# Wiseco Piston Pics and Comments



## blsnelling (Feb 20, 2010)

As most of you know, I've been in Orlando on business travel this week. So I'm just now getting around to posting about these new Wiseco pistons that came Monday.

First of all, the quality of the forgings looks excellent. They all use thin 1mm rings. The 066 rings have end gaps of .009". Piston to cylinder clearance is about .0015"-.002", as best as I can measure.

My scale can only measure in .2 oz increments, so not very accurate at this weight. The factory Mahle piston came in at 3.0 and the Wiseco at 3.4, for nearly a 15% weight increase.

I've run into a couple rather serious issues. The 066 piston is much wider between the pin bosses, leaving .180" play of the piston from side to side, allowing the needle bearing to come out of the rod by the same amount. I do not yet know if this is an issue on any of the other pistons. It looks like I'll have to have a set of bushing/spacers machined up to take up that gap. That's going to add more weight to an already heavier piston.

The 044 piston looks to have a manufactures defect, where the ring end pins are way off center. This is allowing one ring to drop into the intake and the other into a transfer port. This piston is unuseable. The pins are properly centered on all of the other pistons.


This is the 044 piston. Notice how far off center the pins are to the right.







Well right of the window.






Well into the window.






The pencil marks are where the pins are.







LOTS of metal around the pin bosses. That's where all the extra weight is.


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## blsnelling (Feb 20, 2010)

This is the 372 piston.






















Here's one of the thin 1mm rings. Notice how it's shaped to fit around and over the locating pins. These rings can be install either side up.


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## blsnelling (Feb 20, 2010)

Here's the issue with the 066 piston. I can' see this being right, so I figure I'll have to have Nik make me up some spacers.


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## Rounder (Feb 20, 2010)

Hmmm, for the money, I'll stick with Meteor - thanks for the post- Sam


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## albert (Feb 20, 2010)

Spacers and and hi rpm usually not a good idea.


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## volks-man (Feb 20, 2010)

i want to see one of these pistons fail.
i am not hoping for a failure, nor do i expect one.

i want to know if a forged piston melting down will leave you with an unusable cylinder more often than a standard soft piston.


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## blsnelling (Feb 20, 2010)

albert said:


> Spacers and and hi rpm usually not a good idea.



What's the alternative?


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## volks-man (Feb 21, 2010)

albert said:


> Spacers and and hi rpm usually not a good idea.





blsnelling said:


> What's the alternative?



meteor?


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## blsnelling (Feb 21, 2010)

Hopefully that's still an option, should it need to be. However, the skirts are a little wider on this Wiseco piston, and I ported the cylinder before installing it. I think I'm still ok though with a stock width piston. But I intend to make this piston work. It's just a matter of finding the right solution. A wider needle bearing would be ideal.


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## brncreeper (Feb 21, 2010)

"free port" needle bearings?:monkey:


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## blsnelling (Feb 21, 2010)

brncreeper said:


> "free port" needle bearings?:monkey:


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## Stihl088stock (Feb 21, 2010)

Wow, these are a lot "porkier" than I thought they would be.

That 066 slop is no-good at all!


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## weimedog (Feb 21, 2010)

blsnelling said:


> What's the alternative?



If you shim the bearing thats enough. The rod will center based on where it is on the crank. My bet is Wiseco will figure this out. The "windows" look small...will they flow? Those pins just don't want to be over a port, other than that who cares.

I've also seen needle bearings with wider shoulders to take space...wonder if thats what they had in mind.


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## brncreeper (Feb 21, 2010)

blsnelling said:


>


Oh, I see where the play is now. OK, carry on...


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## mtngun (Feb 21, 2010)

blsnelling said:


> However, the skirts are a little wider on this Wiseco piston, and I ported the cylinder before installing it.


Ah ....... wider skirts..... wider ports. That's one potential advantage.



> A wider needle bearing would be ideal.


Good on you for being sharp enough to notice the problem with the fit of the needle bearing. Darned, that may be expensive for Wiseco to re-engineer.

What material does Nik suggest for the spacers ? I dunno if a plastic material would hold up in a saw, but if it would, that would be ideal. Metal spacers would rattle around and perhaps cause damage unless they fit on the pin perfectly. 

Thank you for the honest and detailed report. 

Question -- how much meat between the top ring and the top of the piston ? I'm wondering how much could be safely shaved off to make a pop-up, since Grande Dog has yet to recognize the huge market potential for a cast pop-up piston for the 066 and 066BB (hint, hint ).


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## Stihl088stock (Feb 21, 2010)

weimedog said:


> I've also seen needle bearings with wider shoulders to take space...wonder if thats what they had in mind.



If they had that in mind, they should include one with the piston!!! Something is goofy.


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## blsnelling (Feb 21, 2010)

The OEM needle bearing is 12x17x13. That means something like a 12x17x17 would work. Anyone know if such a critter exists?


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## parrisw (Feb 21, 2010)

blsnelling said:


> Hopefully that's still an option, should it need to be. However, the skirts are a little wider on this Wiseco piston, and I ported the cylinder before installing it. I think I'm still ok though with a stock width piston. But I intend to make this piston work. It's just a matter of finding the right solution. A wider needle bearing would be ideal.





blsnelling said:


> The OEM needle bearing is 12x17x13. That means something like a 12x17x17 would work. Anyone know if such a critter exists?



Brad I ended up with a bunch of needle bearings in my stock acquisition. I'll have a look, how exactly do you measure one of those? Measure on the needles or the cage?


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## kevlar (Feb 21, 2010)

I don't think the space between the rod and the piston will matter, I see this in snowmobile engines all the time,once located inside the cylinder it ain't going anywhere!


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## parrisw (Feb 21, 2010)

kevlar said:


> I don't think the space between the rod and the piston will matter, I see this in snowmobile engines all the time,once located inside the cylinder it ain't going anywhere!



I think he is worried about the bearing coming out of the rod slightly.


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## blsnelling (Feb 21, 2010)

parrisw said:


> Brad I ended up with a bunch of needle bearings in my stock acquisition. I'll have a look, how exactly do you measure one of those? Measure on the needles or the cage?



I looked through all the other Stihl saw IPLs and don't see anything close.


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## Stihl088stock (Feb 21, 2010)

kevlar said:


> I don't think the space between the rod and the piston will matter, I see this in snowmobile engines all the time,once located inside the cylinder it ain't going anywhere!



LoL... problem is the bearing won't stay centered... have another beer!


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## parrisw (Feb 21, 2010)

blsnelling said:


> I looked through all the other Stihl saw IPLs and don't see anything close.



You looked through all the IPL's??????? How many is that!! I'll still look, there could be some there for cut off saws, and trimmers.


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## blsnelling (Feb 21, 2010)

kevlar said:


> I don't think the space between the rod and the piston will matter, I see this in snowmobile engines all the time,once located inside the cylinder it ain't going anywhere!



The space isn't a problem at all for the piston. The problem is that there's nothing to keep the bearing in the rod all the way.


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## blsnelling (Feb 21, 2010)

parrisw said:


> You looked through all the IPL's??????? How many is that!! I'll still look, there could be some there for cut off saws, and trimmers.



Only in the saw IPLs that I have. Even a 12x17x15 would probably work. The entire wrist pin doesn't have to be covered.


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## kevlar (Feb 21, 2010)

parrisw said:


> I think he is worried about the bearing coming out of the rod slightly.



I understand that,but like I said snowmobile pistons are the same way they slide back and forth on the wristpin quite a bit,and the wristpin bearing sliding out the side is a non issue.


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## Justsaws (Feb 21, 2010)

I think Shinidaiwa use spacers along with some other brands. I would try and find a longer bearing. Nothing comes to mind at the moment though.

FourPaws made some posts along time ago about shimming piston/rods.

Lots of meat on that piston your grinder gonna need be busy.


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## parrisw (Feb 21, 2010)

Did ya check the clutch bearings?? This is the closest I have is a 
9512 003 3760 Its a clutch bearing out of a 045, 14x17x17


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## parrisw (Feb 21, 2010)

kevlar said:


> I understand that,but like I said snowmobile pistons are the same way they slide back and forth on the wristpin quite a bit,and the wristpin bearing sliding out the side is a non issue.



How much is still in the rod though?


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## kevlar (Feb 21, 2010)

take another look at the picture, brad has the rod pushed all the way over when in the cylinder this will be impossible,so with the rod centered worst case half of what is shown in the pic could possiby be showing that does not seem like a whole lot to me? Like edge of bearing housing?


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## parrisw (Feb 21, 2010)

kevlar said:


> take another look at the picture, brad has the rod pushed all the way over when in the cylinder this will be impossible,so with the rod centered worst case half of what is shown in the pic could possiby be showing that does not seem like a whole lot to me? Like edge of bearing housing?



Ya your right, probably not an issue.


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## teacherman (Feb 21, 2010)

Looks like somebody in the design dept. didn't see to it that it fit properly on the crankshaft of the saw for which it was designed. That, and the extra metal weight around the pin make it seem a rather poor alternative to OEM, Episan, or Meteor. Wonder what all the fuss is about. I would only use one if it were the only choice. They are a mfr. of premium performance products, and are accustomed to properly fitting AM pistons to various machines. I would say it's back to the CAD board (computer aided design, not our CAD, lol).


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## Jacob J. (Feb 21, 2010)

teacherman said:


> Looks like somebody in the design dept. didn't see to it that it fit properly on the crankshaft of the saw for which it was designed. That, and the extra metal weight around the pin make it seem a rather poor alternative to OEM, Episan, or Meteor. Wonder what all the fuss is about. I would only use one if it were the only choice. They are a mfr. of premium performance products, and are accustomed to properly fitting AM pistons to various machines. I would say it's back to the CAD board (computer aided design, not our CAD, lol).



Maybe they wanted to make this piston easily transferable to a Husky 288... 



parrisw said:


> Brad I ended up with a bunch of needle bearings in my stock acquisition. I'll have a look, how exactly do you measure one of those? Measure on the needles or the cage?



Measure the cage grasshopper...

I think there's a Husky wrist pin bearing, like the one in the 380CD, that's pretty close to the aforementioned dimensions...


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## AUSSIE1 (Feb 21, 2010)

When talking weight, a wider bearing would equal there abouts with bushings.

As Kevlar stated, the needles wouldn't protrude but there would be less contact at the other side.
With that being said Jacob J has run the short 066/660 bearings in the 066/660 pistons in the 288XP's wider rod with success.


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## Jacob J. (Feb 21, 2010)

AUSSIE1 said:


> When talking weight, a wider bearing would equal there abouts with bushings.
> 
> As Kevlar stated, the needles wouldn't protrude but there would be less contact at the other side.
> With that being said Jacob J has run the short 066/660 bearings in the 066/660 pistons in the 288XP's wider rod with success.



I have done that yes, but the wrist pin bosses of the 066 pistons I installed on the 288 rods were snug up against the rod, so there was no possible movement of the piston. The bearing inside had very little room to move, maybe around 1.25mm on each side.


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## rxe (Feb 21, 2010)

If these are pre production, then you've found a few problems, they'll fix them. I would imagine the wrist pin slop is a question of tweaking a few figures on a milling machine, hopefully not re-creating a forging blank from scratch.

Are you also saying that the pins are in the wrong place and they will catch on the windows? That would be bad, but easily fixed.


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## WoodChuck'r (Feb 21, 2010)

I don't have much to contribute, this is (for the most part) rather new to me. I'm learning a lot though, good stuff.


But DANG! What kind of camera are you using?! Those photos are beautiful!!


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## wigglesworth (Feb 21, 2010)

rxe said:


> If these are pre production, then you've found a few problems, they'll fix them.



To my understanding, they have been selling them already. I wonder if there has been any failures? I for one am kinda surprised that a Premier, High performance, USA made piston manufacture would let something like this out their door, in fact im kinda shocked. According the Brad, the 044 piston is unusable due to ring end pin's, the 046 piston is unusable due to ring end pin's and the 066 piston is, IMHO, very iffy on it's usability unless using another style bearing and/or spacers, which, in turn, will most likely put it right up there with OEM prices, not even mentioning the weight increase of said solution. 


They do look pretty though........:monkey:


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## mdavlee (Feb 21, 2010)

The pistons look great. Maybe they have changed the ring end locations on them already and you got some of the early ones.


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## hotshot (Feb 21, 2010)

*Recommended clearance*

What is the recommended design for cage to side bosses total clearance?
I have seen up to 0.025" on some aftermarket Stihl pistons, but not OEM Mahle. 

A longer bearing (12/17/14.4) is listed in the INA Needle Bearing section, under the piston/wrist pin section, but you'd still need two shims. 

http://www.schaeffler.com/remotemedien/media/_shared_media/library/downloads/tpi94_de_en.pdf

Sprocket bearings are not the same (too fragile)


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## Cliff R (Feb 21, 2010)

The wrist pin being able to move off center isn't going to hurt anything, the rod will stay well centered with plenty of contact area with needle bearings in actual use.

I still don't get a "warm and fuzzy" putting things together that could be better. I'd opt for a longer bearing with less movement anyhow, last resort would be to fabricate/obtains some small/hardened spacers to keep the bearing centered better.

I'm not an expert on these little engines when it comes to weight of the reciprocating and spinning parts. Common sense would drive me to want the finished piston weight on par with the weight of an OEM piston.

Brad, for accurately measuring the bores, a low cost and easy method is to obtain some telescoping gauges, they have round ends on them. Been using them here for decades, and with a little practice you can accurately measure bore sizes, mic the piston at the widest part of the skirt, and come up with actual piston to wall clearance.

Most modern allows used for forgings do not require much clearance, at least in comparison to older designs. Cast pistons being of completely different construction/materials hold their dimensions, shape, diameter better than forgings, and can be set up tighter. In automotive applications, we used to have to run .0035-.0055" piston to wall clearance with forged pistons. The cast pistons typically .0005-.0015". No problem at all with modern forgings at .002" if a torque plate is used for final bore finish. 

The key with piston clearance, is to make sure that it doesn't absorb enough heat and expand enough to "drag" in the bore. In most cases they will make the needed clearance and continue to run. If too tight, of course, the smear enough material to lock up and/or comprimise ring seal, etc.

Another advantage to a casting is less piston "rock" with a cold engine. This increases engine life as the rings don't wear out as fast. I would certainly want the saw engine fully warmed up before burying a 24" bar in a hard peice of Oak....FWIW.....Cliff


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## volks-man (Feb 21, 2010)

*why?*

*why does the world need a forged saw piston?*

it is heavier. probably negatively effecting power.

it is more durable? so, 2000+ hours or so on a pro saw isn't enough? and it is still aluminum folks. dirt will still eat it up and so will lean running and straight gas.

more money? i can buy a good quality meteor and have money left for other parts for the rebuilds.

questionable quality. yeah, it is start-up... but haven't they shipped already?

what will happen when a forged piston melts down? will you loose the jug too every time?

i'll stick with old school cast pistons, thanks.


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## Tzed250 (Feb 21, 2010)

.


The forged piston might live with 220lbs of compression...


.


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## TRI955 (Feb 21, 2010)

Justsaws said:


> I think Shinidaiwa use spacers along with some other brands. I would try and find a longer bearing. Nothing comes to mind at the moment though.
> 
> FourPaws made some posts along time ago about shimming piston/rods.
> 
> Lots of meat on that piston your grinder gonna need be busy.



Justsaws is right, they used spacers on the 550/575/577/680 saws. The only problem is they're all for a 11mm pin. The 695 and 757 both have a 12mm pin but don't use the spacers...


Mike


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## 2000ssm6 (Feb 21, 2010)

Nice!


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## Evan (Feb 21, 2010)

so are these piston available through baileys now or are these the batch that brad is testing.

i think they look very good. i like the beefy pin bosses though i would do some grinding there.

they will get it right.


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## Tzed250 (Feb 21, 2010)

Evan said:


> so are these piston available through baileys now or are these the batch that brad is testing.
> 
> i think they look very good. i like the beefy pin bosses though i would do some grinding there.
> 
> they will get it right.



Adding to cart... 
Home > Item Detail 
Wiseco Piston Assembly (54mm) for Stihl 066, MS 660 Item # WSC 3286 
Only $129.95 

Qty: 

In Stock 


Average rating: Rate this!



Upgrade your stock cast piston to a forged piston from Wiseco. Wiseco forged pistons add durability, and the precision demanded by high performance engines of every category. Forgings have condensed grain that is aligned to the features of the part, which produces higher mechanical properties, and resistance to impact and fatigue. Each forging is designed to optimize the strength-to-weight ratio, and maximize performance. Compared to cast pistons, forgings are tougher and more durable, and will stand up to the abuse of high RPM engines. Wiseco pistons are used in automobiles, motorcycles, ATV, outboard marine or anywhere superior quality is a must. Bailey’s now offers you this same quality for your chainsaw.


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## mtngun (Feb 21, 2010)

volks-man said:


> *why does the world need a forged saw piston?*
> 
> i'll stick with old school cast pistons, thanks.


I agree, but we've had that discussion on another thread, so I won't keep ragging on it.

For an extreme "hot" saw, yes. For nitrous, yes. Is there such a thing as a turbocharged chainsaw ? 

Oh, well. The wiseco piston is beautiful, a work of industrial art. 

Good luck with the project, Brad.


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## wooddog (Feb 21, 2010)

Sir from what I have read on the wiseco piston kits come with special supplied wrist pin bearing, wrist pin, circlips, rings in a complete kit. Maybe Bailey's sent floor scraps for some reason to be tested . 
Was piston kits even in the wiseco box and complete kits?

Looks like they tried to make these pistons :newbie: proof


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## Tzed250 (Feb 21, 2010)

mtngun said:


> Oh, well. The wiseco piston is beautiful, a *work of industrial art*.
> 
> Good luck with the project, Brad.





True, but I submit this...


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## Evan (Feb 21, 2010)

129?????
as good as i know them to be in the 2 stroke sleds and bikes ill pass at 129 atleast untill they get the bugs worked out and the price drops to 50-75 bucks.

i think you can buy mahle pistons or stihl stamped chicumn garbage for that price


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## Stihl Crazy (Feb 21, 2010)

We are paying $125 here for some OEM pistons, Stihl 260 for example.


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## blsnelling (Feb 21, 2010)

kevlar said:


> I understand that,but like I said snowmobile pistons are the same way they slide back and forth on the wristpin quite a bit,and the wristpin bearing sliding out the side is a non issue.





kevlar said:


> take another look at the picture, brad has the rod pushed all the way over when in the cylinder this will be impossible,so with the rod centered worst case half of what is shown in the pic could possiby be showing that does not seem like a whole lot to me? Like edge of bearing housing?



You make a valid point. I actually had this bolted together and was going to run it. But I got nervous and brought it to you guys for your advice.

With the rod centered between the pin bosses, the bearing can only come out of the rod 2.25mm. With a 13mm wide bearing, that still leaves better than 10mm of bearing in the rod. So what's your opinion here? Make spacers, or let it be?



Jacob J. said:


> I think there's a Husky wrist pin bearing, like the one in the 380CD, that's pretty close to the aforementioned dimensions...



So check out the bearing for a 380CD? Any idea what the size of it is?



hotshot said:


> A longer bearing (12/17/14.4) is listed in the INA Needle Bearing section, under the piston/wrist pin section, but you'd still need two shims. http://www.schaeffler.com/remotemedien/media/_shared_media/library/downloads/tpi94_de_en.pdf


I'll definately check that out.



Cliff R said:


> I'd opt for a longer bearing with less movement anyhow, last resort would be to fabricate/obtains some small/hardened spacers to keep the bearing centered better.


So you'd leave it as is before you fabbed up spacers? I have the orignal worn out Mahle piston I though I'd machine down the pin bosses to size, if I went that route.



WoodChucker81 said:


> But DANG! What kind of camera are you using?! Those photos are beautiful!!


Canon 7D with 24-105 f4 L IS lens.


These pistons came with rings, wrist pin, and circlips. No needle bearing was included. Squish with an OEM gasket is .022". These are production pistons AFAIK. Only the 440 piston appears to have the pins in the wrong location. I've not yet fitted up the 372 or 460 piston, but they look ok.


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## kevlar (Feb 21, 2010)

blsnelling said:


> You make a valid point. I actually had this bolted together and was going to run it. But I got nervous and brought it to you guys for your advice.
> 
> With the rod centered between the pin bosses, the bearing can only come out of the rod 2.25mm. With a 13mm wide bearing, that still leaves better than 10mm of bearing in the rod. So what's your opinion here? Make spacers, or let it be?
> 
> ...



I would run it, like I stated snowmobile engines have far more play as they rock around on the wristpin. I even think that this may allow more oil to enter the bearing? I remember a post from Lakeside about high rpm and spacers in saws and that it led to failures.


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## blsnelling (Feb 21, 2010)

kevlar said:


> I remember a post from Lakeside about high rpm and spacers in saws and that it led to failures.



I seem to remember something about that as well. This cylinder is ported too, so will be running higher than factory RPMs. Would you even bother with sourcing a wider bearing? Is 10mm enough bearing in the rod?


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## kevlar (Feb 21, 2010)

I guess if you need piece of mind that there probably is a bearing out there that would work. Myself ,I would just run it ,I bet the bearing never even leaves the rod.


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## Mad Professor (Feb 21, 2010)

blsnelling said:


> As most of you know, I've been in Orlando on business travel this week. So I'm just now getting around to posting about these new Wiseco pistons that came Monday.
> 
> First of all, the quality of the forgings looks excellent. They all use thin 1mm rings. The 066 rings have end gaps of .009". Piston to cylinder clearance is about .0015"-.002", as best as I can measure.
> 
> ...


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## blsnelling (Feb 21, 2010)

I'll have to go back and fix that. It's only on the 440 piston.


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## splitpost (Feb 21, 2010)

Sure is pretty ,but no way would i run it ,just been down that very road with my 044bb piston ,theres nothing to keep the rod from walking sideways and off the centreline ,looks like it might cause bearing failure ,just my 2c


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## rob066 (Feb 21, 2010)

I sure wouldnt use one of those pistons at the moment The clearance issue makes to many insucurities. I want to make a useable saw that I can make revenue with. Not scrap for the local scrap yard.


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## Hddnis (Feb 21, 2010)

On the piston with the pins in the wrong location is that because it's ported or is it wrong for a stock jug too?

Can't you move the pin locations? I can see where if you are trying to test it as an out of the box piston you wouldn't want to do that though.


Mr. HE


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## deezlfan (Feb 21, 2010)

Four pages of back and forth regarding the bearings and not one thought of asking the piston manufacturer why it was made that way? Wiseco is made in the USA, is it not? The company has millions of pistons in service, perhaps they have a good reason for the design? A phone call or e-mail may bring the answer we need. Maybe one of the engineers could provide some insight as to the requirements for forged piston construction? Do forged pistons behave in a different manner than cast pistons regarding expansion and heat cycles? Might save a ton of time and broken test pieces vs jury-rigging a bearing when it was not necessary?

It seems to me that the intent was to evaluate the piston and let us know if it was an alternative to OEM. Tossing modifications into the mix without input from the manufacturer doesn't make sense to me. Enough soapboxing. I'll go read some oil threads as penance for my insolance.


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## blsnelling (Feb 21, 2010)

Hddnis said:


> On the piston with the pins in the wrong location is that because it's ported or is it wrong for a stock jug too?
> 
> Can't you move the pin locations? I can see where if you are trying to test it as an out of the box piston you wouldn't want to do that though.
> 
> ...



They're simply in the wrong location. The piston was not indexed correctly when the pins where installed.



deezlfan said:


> Four pages of back and forth regarding the bearings and not one thought of asking the piston manufacturer why it was made that way? Wiseco is made in the USA, is it not? The company has millions of pistons in service, perhaps they have a good reason for the design? A phone call or e-mail may bring the answer we need. Maybe one of the engineers could provide some insight as to the requirements for forged piston construction? Do forged pistons behave in a different manner than cast pistons regarding expansion and heat cycles? Might save a ton of time and broken test pieces vs jury-rigging a bearing when it was not necessary?
> 
> It seems to me that the intent was to evaluate the piston and let us know if it was an alternative to OEM. Tossing modifications into the mix without input from the manufacturer doesn't make sense to me. Enough soapboxing. I'll go read some oil threads as penance for my insolance.



Kind of hard to get ahold of manufactures on a weekend isn't it?


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## Terry Syd (Feb 22, 2010)

*Pin boss*

My guess on the extra space on the wrist pin has to do with the construction of forged pistons. The pin bosses go all the way to the top of the piston. If the pin boss was moved in that far the piston would be a heck of a lot heavier.

Of course, they could then mill the sides of the piston down to trim the excess off the outside of the pin boss, but would that leave enough skirt width to seal the ports?

I figure it was a weight saving option that created other issues.


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## deezlfan (Feb 22, 2010)

> Kind of hard to get ahold of manufactures on a weekend isn't it?



Yes, it is. But my basic point still holds. My comments were intended as a reasonable contribution to the thread, not to start a pissin' match. I am not prepared to condemn the pistons just yet as I feel there may be a perfectly good reason for it's construction. It just make sense to ask the experts that built the piston to me. I thought my input might make a useful addition to the thread vs writing off the entire affair as a waste of time without considering the facts.


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## Cliff R (Feb 22, 2010)

Brad, the wrist pin bearing offset will be fine in actual use. There is plenty of support left between the parts, the piston will not tilt off center on the pin, plenty of lubrication will make it to the needles, etc.

It just could be better, and something to take up with the manufacturers early in the game.

I just finished assembling a high dollar engine yesterday that used a host of aftemarket parts. Every single part was found to be well within specifications, which is often not the case. We've found plenty of problems with aftermarket parts, most of which are produced offshore, and worked with the supplyiers of these parts to get them up to par and on spec. This process is not a fast one, but the offshore produced engine parts have continued to increase in quality and fit, to a point where they are a very good bargain for the engine builds we use them in.

Since you are working with an American company, I'm sure some direct feedback to Weisco will remedy the problem(s) in short order.....Cliff


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## blsnelling (Feb 22, 2010)

Well, I'd have this 066 together and running if the dealer hadn't forgotten to order my gasket/seal kit. I faxed a list of 20 PNs to them last Monday, looking forward to putting it together when I got home Saturday. Unfortunately, they missed the gasket kit. It should be here tomorrow though.


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## brad1000s (Feb 22, 2010)

blsnelling said:


> The OEM needle bearing is 12x17x13. That means something like a 12x17x17 would work. Anyone know if such a critter exists?



wiseco has a bearing that measures 12x17x14.2 part number is B1015


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## blsnelling (Feb 22, 2010)

brad1000s said:


> wiseco has a bearing that measures 12x17x14.2 part number is B1015



Who would stock those in this part of the country? I'd like to order one.

Here are the PNs on the pistons.

066 - 10919N05400 - 4719J - I threw away the box and the stamping's kind of hard to read. Perhaps the N is an M like the rest of the pistons.

044 - 10918M05000 - 0952C - That's on the box. On the piston, the M looks like a K.

046 - 10920M05200 - 1251K

372 - 10921M05000 - 6946K


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## blsnelling (Feb 22, 2010)

It looks like all of the 044 pistons are defective, so it's back to the manufacturer for a fix. No word on the 066 pin boss situation yet.


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## wooddog (Feb 22, 2010)

Maybe Bailey's needs to know how to order a complete piston kit with the correct supplied wrist pin bearing as Mr. Leeha did when ordering his custom made wiseco 166 pistons. They came from wiseco with longer wrist pin bearing in the kit. Just a thought Sir. http://www.arboristsite.com/showthread.php?t=123864&highlight=dolmar+166+piston


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## blsnelling (Feb 22, 2010)

wooddog said:


> Maybe Bailey's needs to know how to order a complete piston kit with the correct supplied wrist pin bearing as Mr. Leeha did when ordering his custom made wiseco 166 pistons. They came from wiseco with longer wrist pin bearing in the kit.  Just a thought Sir. http://www.arboristsite.com/showthread.php?t=123864&highlight=dolmar+166+piston



There is no mention of the wrist pin bearing anywhere in that thread. No bearing pictured with the piston kit either.


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## wooddog (Feb 22, 2010)

blsnelling said:


> There is no mention of the wrist pin bearing anywhere in that thread. No bearing pictured with the piston kit either.



Someone needs to delete one of the wiseco threads or combine them. Having to post the same thing in two threads is ridiculous. Choose a thread. I'm done double posting. Brad and I have had to double post for what 

Sir that is what the PM is there for. You can get all the little details if you just ask Mr. Leeha. Lot of good information being shared in PM's.


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## Freakingstang (Feb 22, 2010)

that sucks about the pin location on the 44 pistons...


As far as weight is concerned, Any forged piston is going to be noticably heavier than a cast or hyperuetectic piston. Has to do with the heavier material and the molecule compositon.

The last set of forged pistons i used in one of my car engine builds were about 300 grams heavier than its cast counterpart. If you want to play, you gotta pay

These pistons are not "marketed" for stock rebuilds....

Wiesco is based out of Cleveland...I've had a couple sets of custom pistons made and they are one of the best piston manufactures I've seen


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## blsnelling (Feb 22, 2010)

wooddog said:


> Someone needs to delete one of the wiseco threads or combine them. Having to post the same thing in two threads is ridiculous. Choose a thread. I'm done double posting. Brad and I have had to double post for what
> 
> Sir that is what the PM is there for. You can get all the little details if you just ask Mr. Leeha. Lot of good information being shared in PM's.



I'm wondering why the doulbe post as well. 

Unfortunately, the info in PMs doesn't help the rest of us.


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## Hddnis (Feb 22, 2010)

wooddog said:


> Someone needs to delete one of the wiseco threads or combine them. Having to post the same thing in two threads is ridiculous. Choose a thread. I'm done double posting. Brad and I have had to double post for what
> 
> Sir that is what the PM is there for. You can get all the little details if you just ask Mr. Leeha. Lot of good information being shared in PM's.





Are you naturally this grouchy and superior in your demeanor or do you save it just for us here at AS?



Mr. HE


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## indiansprings (Feb 22, 2010)

Since they are obviouosly only being made for Bailey's, it makes you wonder if Bailey's has the right individual sourcing these internal engine parts for them. First the issues with the import products and now the domestic product, not saying I'm right, but it is possible. It might benefit them to hire a guy with the technical expertise on interal engine components. Enginners speak a different language than mechanics or your typical purchasing agent.
Just saying it could save them alot of time and money,development cost and loss of customer confidence. Just a thought, Brad has done a good job in pointing out the potential issues beyond fit and cosmetics, may save someone a blown or jacked up saw.


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## blsnelling (Feb 22, 2010)

Here's Baileys and Wisecos answer on the 066 bearing question. I'll post another pic in a little while with the rod centered and the bearing to the side. That will demonstrate how little bearing can come out of the rod. The question still remains, why build it that way? I'm sure there's a technical reason, but I like to know those kinds of things.
*
"We discussed the bearing float vs. wrist pin tower distance prior to production. Our lead engineer questioned this early on and we gave him the feed back of being a "Bottom Guided" crank assembly. When the parts are assembled in the engine the crank keeps the rod in center of the towers, but you will still have a small portion of the bearing that will be exposed. This is acceptable, just not as extreme as the "bench test" picture that was posted on that link suggests. The crank centers the rod to the piston, the pistons remains center in the bore, but yes.. the bearing will slide side to side and have minimal exposure which is acceptable."*

Interestingly enough, thats the answer you guys came up with. I suggested putting a note in the kits indicating as such. That would sure save the end user a lot of time, concerns, and questions.


----------



## Bowtie (Feb 22, 2010)

blsnelling said:


> Here's Baileys and Wisecos answer on the 066 bearing question. I'll post another pic in a little while with the rod centered and the bearing to the side. That will demonstrate how little bearing can come out of the rod. The question still remains, why build it that way? I'm sure there's a technical reason, but I like to know those kinds of things.
> *
> "We discussed the bearing float vs. wrist pin tower distance prior to production. Our lead engineer questioned this early on and we gave him the feed back of being a "Bottom Guided" crank assembly. When the parts are assembled in the engine the crank keeps the rod in center of the towers, but you will still have a small portion of the bearing that will be exposed. This is acceptable, just not as extreme as the "bench test" picture that was posted on that link suggests. The crank centers the rod to the piston, the pistons remains center in the bore, but yes.. the bearing will slide side to side and have minimal exposure which is acceptable."*
> 
> .



That bearing float issue is a definite deal killer for me. I applaud Baileys BIG TIME for the risk and all they are taking trying these kits out, but for that kind of money I expect perfection for a damn chainsaw piston. Im sure that will happen in time.

They can call it acceptable to them (Wiseco), but it is unacceptable to me.


----------



## Paul001 (Feb 22, 2010)

blsnelling said:


> Here's Baileys and Wisecos answer on the 066 bearing question. I'll post another pic in a little while with the rod centered and the bearing to the side. That will demonstrate how little bearing can come out of the rod. The question still remains, why build it that way? I'm sure there's a technical reason, but I like to know those kinds of things.
> *
> "We discussed the bearing float vs. wrist pin tower distance prior to production. Our lead engineer questioned this early on and we gave him the feed back of being a "Bottom Guided" crank assembly. When the parts are assembled in the engine the crank keeps the rod in center of the towers, but you will still have a small portion of the bearing that will be exposed. This is acceptable, just not as extreme as the "bench test" picture that was posted on that link suggests. The crank centers the rod to the piston, the pistons remains center in the bore, but yes.. the bearing will slide side to side and have minimal exposure which is acceptable."*
> 
> Interestingly enough, thats the answer you guys came up with. I suggested putting a note in the kits indicating as such. That would sure save the end user a lot of time, concerns, and questions.



Context would help with the above answer. Who's lead Engineer? Who gave him the feed back of being a "Bottom Guided" crank?

Sounds like it was already spec'ed and ready to go, changes would have cost money and time. Hopefully they didn't swap their time and money for customers time and money.

Seem like a few silly mistakes or forgotten ECN's.


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## Terry Syd (Feb 22, 2010)

*Pop-up*

I'd expect that a lot of people would discount the wristpin gap issue if the piston came with a pop-up. With the pop-up, they would probably be willing to make some compromises (such as a longer bearing) in order to have a high compression piston.

Is there any feedback on why there isn't a pop-up/high compression piston?


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## 2000ssm6 (Feb 22, 2010)

Terry Syd said:


> Is there any feedback on why there isn't a pop-up/high compression piston?



Not enough demand, we are a very small peice of the pie.


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## parrisw (Feb 22, 2010)

2000ssm6 said:


> Not enough demand, we are a very small peice of the pie.



Ya, plus I'm wondering, how it would work for every saw, since some can be slightly different. If your shooting for squish to within a couple of thou. I'm sure some saw can differ that much easy. Better off to make the popup yourself.


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## 2000ssm6 (Feb 22, 2010)

Bowtie said:


> They can call it acceptable to them (Wiseco), but it is unacceptable to me.



I expected a lot more from Wiseco than that, sad.


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## 2000ssm6 (Feb 22, 2010)

parrisw said:


> Ya, plus I'm wondering, how it would work for every saw, since some can be slightly different. If your shooting for squish to within a couple of thou. I'm sure some saw can differ that much easy. Better off to make the popup yourself.



Yup, pop ups are "one of a kind" so to speak. The same one won't work in a different saw unless they(bases and squish band) are measured and machined accordingly.


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## Bowtie (Feb 22, 2010)

Looking at the pic Brad posted, that is a lot of bearing floating to and fro. The side loads on the small rod end cant be good. If there was a way to keep the bearing in the center of the rod other than spacers, no big deal. But with the current piston configuration, that isnt possible.


----------



## leeha (Feb 22, 2010)

blsnelling said:


> There is no mention of the wrist pin bearing anywhere in that thread. No bearing pictured with the piston kit either.



You are correct Brad. 
i forgot to put the bearing in the photo.
The bearing is not part of the Wiseco piston
kit. I had to buy them seperate from Wiseco
and supply them with every kit.

The width between the pin bosses is in there
machining process and can't make that dimension
as narrow as the stock piston. Not sure why.
I wasn't happy with that so they did the research
and found a bearing to make up the addition clearance.
The cage of the bearing actually a bit wider and not the 
needles so the needles are still completely in the rod.


Lee


----------



## blsnelling (Feb 22, 2010)

leeha said:


> You are correct Brad.
> i forgot to put the bearing in the photo.
> The bearing is not part of the Wiseco piston
> kit. I had to buy them seperate from Wiseco
> ...



Thanks Lee.


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## 2000ssm6 (Feb 22, 2010)

Bowtie said:


> Looking at the pic Brad posted, that is a lot of bearing floating to and fro. The side loads on the small rod end cant be good. If there was a way to keep the bearing in the center of the rod other than spacers, no big deal. But with the current piston configuration, that isnt possible.



Who would spend $130-140 on a piston then have to get spacers machined? Even with spacers, will these pistons go 1000-2000 hours with all that flop? Sounds retarded to me but I'll stick with Stihl and Mahle.


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## wigglesworth (Feb 22, 2010)

2000ssm6 said:


> Yup, pop ups are "one of a kind" so to speak. The same one won't work in a different saw unless they(bases and squish band) are measured and machined accordingly.



An 028 super piston has a factory pop-up that would be a good design to model for a universal fit. 028 Piston


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## blsnelling (Feb 22, 2010)

Bowtie said:


> Looking at the pic Brad posted, that is a lot of bearing floating to and fro. The side loads on the small rod end cant be good. If there was a way to keep the bearing in the center of the rod other than spacers, no big deal. But with the current piston configuration, that isnt possible.



First of all, I'm not real happy about this either. But the engineers say it's OK. I'm going to run it initially with the OEM bearing. I do intend to buy the wider B1015 bearing though. That'll give me a chance to go back in there after running it with the OEM bearing.

Do remeber that the rod will never be off to the side like I posted. It will be centered as in the pic below.


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## wigglesworth (Feb 22, 2010)

blsnelling said:


> First of all, I'm not real happy about this either. But the engineers say it's OK. I'm going to run it initially with the OEM bearing. I do intend to buy the wider B1015 bearing though. That'll give me a chance to go back in there after running it with the OEM bearing.
> 
> Do remeber that the rod will never be off to the side like I posted. It will be centered as in the pic below.




Isnt there side to side movement of the rod on the crank? Wont that allow the rod to float to the side?


----------



## leeha (Feb 22, 2010)

2000ssm6 said:


> Who would spend $130-140 on a piston then have to get spacers machined? Even with spacers, will these pistons go 1000-2000 hours with all that flop? Sounds retarded to me but I'll stick with Stihl and Mahle.



The Homelite Super 2100 uses spacers
from the factory and they had no problems.


Lee


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## blsnelling (Feb 22, 2010)

wigglesworth said:


> Isnt there side to side movement of the rod on the crank? Wont that allow the rod to float to the side?



Very little. They all do a small amount, by design.


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## blsnelling (Feb 22, 2010)

2000ssm6 said:


> Who would spend $130-140 on a piston then have to get spacers machined? Even with spacers, will these pistons go 1000-2000 hours with all that flop? Sounds retarded to me but I'll stick with Stihl and Mahle.



What flop are you referring to?


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## Jacob J. (Feb 22, 2010)

leeha said:


> The Homelite Super 2100 uses spacers
> from the factory and they had no problems.
> 
> 
> Lee



Some of the Macs used a type of spacer as well, called "thrust washers"...


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## 2000ssm6 (Feb 22, 2010)

blsnelling said:


> What flop are you referring to?



Side to side. When that piston is on the rod ready to be installed, can you move the piston any along the wrist pin to the L or R?


----------



## leeha (Feb 22, 2010)

Jacob J. said:


> Some of the Macs used a type of spacer as well, called "thrust washers"...



Exactly correct.

Lee


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## blsnelling (Feb 22, 2010)

2000ssm6 said:


> Side to side. When that piston is on the rod ready to be installed, can you move the piston any along the wrist pin to the L or R?



All pistons float on the wrist pin, just not normally this much. The crank centers the rod between the pin bosses.


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## 2000ssm6 (Feb 22, 2010)

leeha said:


> The Homelite Super 2100 uses spacers
> from the factory and they had no problems.
> 
> 
> Lee



Good point but Homelite nor Mac make saws worth a crap "anymore". I know they were great saws for their time era. Maybe it worked for them but why doesn't Stihl, Dolmar or husqvarna use these methods today? I just don't see any advantages.....


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## 2000ssm6 (Feb 22, 2010)

blsnelling said:


> All pistons float on the wrist pin, *just not normally this much*. The crank centers the rod between the pin bosses.



That was what I was looking for.


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## leeha (Feb 22, 2010)

2000ssm6 said:


> Good point but Homelite nor Mac make saws worth a crap "anymore". I know they were great saws for their time era. Maybe it worked for them but why doesn't Stihl, Dolmar or husqvarna use these methods today? I just don't see any advantages.....



Maybe they don't anymore.
But back in there day those 
old mac's and Homelites survived
the most demanding conditions and
threw more chips than most.
And that little thrust washer didn't stop them.


Lee


----------



## parrisw (Feb 22, 2010)

2000ssm6 said:


> Who would spend $130-140 on a piston then have to get spacers machined? Even with spacers, will these pistons go 1000-2000 hours with all that flop? Sounds retarded to me but I'll stick with Stihl and Mahle.



Yep, I was thinking the same thing!!

Spacers wouldn't be a big deal IMHO. I'd use brass.


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## wigglesworth (Feb 22, 2010)

I think that the thrust washer is a good idea and would most likely work with no problems. Heck it might just work as it is with the slop in it. However, it stand's to reason that nobody should spend that kind of money on a piston, that is supposed to be a direct replacment, and feel they have to modify, shim, install a new bearing, jerry-rig or whatever to create a usuable piston. This is supposed to be a direct replacment correct? It is *not* identical to an OEM piston, therefore results may vary.......


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## 2000ssm6 (Feb 22, 2010)

leeha said:


> Maybe they don't anymore.
> But back in there day those
> old mac's and Homelites survived
> the most demanding conditions and
> ...



A toast to the old beasts!


----------



## blsnelling (Feb 22, 2010)

2000ssm6 said:


> That was what I was looking for.



I did a little math. The gap is about 2.2mm per side when centered as it would be in operation. Put the 1.2mm wider 12x17x14.2 B1015 bearing in there, and the bearing can only come out of the rod 1mm. I think I got that right.


----------



## Bowtie (Feb 22, 2010)

blsnelling said:


> First of all, I'm not real happy about this either. But the engineers say it's OK. I'm going to run it initially with the OEM bearing. I do intend to buy the wider B1015 bearing though. That'll give me a chance to go back in there after running it with the OEM bearing.
> 
> Do remeber that the rod will never be off to the side like I posted. It will be centered as in the pic below.



Right Brad, but the bearing is free to float from wrist pin boss to wrist pin boss. A certain amount of float is normal, but that is way excessive.

From Lee's post, I wonder why they couldnt machine it closer? Thats weird for a company like Wiseco.


----------



## Tzed250 (Feb 23, 2010)

.

The forging process sets the width between the bosses. Stick your finger in a piece of play-doh. The underside of these pistons is formed in the same manner. Wiseco could have easily made the gap smaller, but then the whole area from pin bore to dome would be filled by metal, not a good thing on an item fighting weight issues. 


.


----------



## blsnelling (Feb 23, 2010)

Cliff R said:


> Brad, the wrist pin bearing offset will be fine in actual use. There is plenty of support left between the parts, the piston will not tilt off center on the pin, plenty of lubrication will make it to the needles, etc.





kevlar said:


> I would run it, like I stated snowmobile engines have far more play as they rock around on the wristpin. I even think that this may allow more oil to enter the bearing? I remember a post from Lakeside about high rpm and spacers in saws and that it led to failures.





Cliff R said:


> The wrist pin being able to move off center isn't going to hurt anything, the rod will stay well centered with plenty of contact area with needle bearings in actual use.
> 
> I still don't get a "warm and fuzzy" putting things together that could be better. I'd opt for a longer bearing with less movement anyhow, last resort would be to fabricate/obtains some small/hardened spacers to keep the bearing centered better.





kevlar said:


> I don't think the space between the rod and the piston will matter, I see this in snowmobile engines all the time,once located inside the cylinder it ain't going anywhere!





kevlar said:


> I understand that,but like I said snowmobile pistons are the same way they slide back and forth on the wristpin quite a bit,and the wristpin bearing sliding out the side is a non issue.





Baileys/Wiseco said:


> "We discussed the bearing float vs. wrist pin tower distance prior to production. Our lead engineer questioned this early on and we gave him the feed back of being a "Bottom Guided" crank assembly. When the parts are assembled in the engine the crank keeps the rod in center of the towers, but you will still have a small portion of the bearing that will be exposed. This is acceptable, just not as extreme as the "bench test" picture that was posted on that link suggests. The crank centers the rod to the piston, the pistons remains center in the bore, but yes.. the bearing will slide side to side and have minimal exposure which is acceptable."



I really appreciate you guys experience and advice. Lot's of people can offer advise based on opinion or gut feeling. But it's a different story when it comes from real world experience. 

With that said, I'd like to dig a little deeper into this. Have you seen sled engines where the bearing actually comes partially out of the rod? I understand that the bearing floating left and right is a non issue. I understand that the rod stays centered between the pin bosses. Do the sled engines use spacers to limit bearing travel?

As indicated by Wiseco engineers, it's said not to be an issue. But I still plan to go back in a a later date to inspect after some run time, and install the wider bearing just for peace of mind. That'll probably also help if/when I decide to sell this saw.


----------



## lone wolf (Feb 23, 2010)

blsnelling said:


> I really appreciate you guys experience and advice. Lot's of people can offer advise based on opinion or gut feeling. But it's a different story when it comes from real world experience.
> 
> With that said, I'd like to dig a little deeper into this. Have you seen sled engines where the bearing actually comes partially out of the rod? I understand that the bearing floating left and right is a non issue. I understand that the rod stays centered between the pin bosses. Do the sled engines use spacers to limit bearing travel?
> 
> As indicated by Wiseco engineers, it's said not to be an issue. But I still plan to go back in a a later date to inspect after some run time, and install the wider bearing just for peace of mind. That'll probably also help if/when I decide to sell this saw.


 run it as intended and blame wiseco if you must but im thinking they should know more than us right?


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## blsnelling (Feb 23, 2010)

Here's the low down on the 440 piston. Distance between the pins is fine, but they're 2mm off center. My measurements show a 1mm difference between pins, but that's a stong 39mm. I can't measure much closer than that with what I have. So it's probably within .5mm. Reguardless, that's not a problem at all. The distance between pin bosses is within .006". Notice the wider skirt width on the Wiseco


----------



## leeha (Feb 23, 2010)

blsnelling said:


> With that said, I'd like to dig a little deeper into this. Have you seen sled engines where the bearing actually comes partially out of the rod? I understand that the bearing floating left and right is a non issue. I understand that the rod stays centered between the pin bosses. Do the sled engines use spacers to limit bearing travel?
> 
> I have worked on and rebuilt many Ski Doo snowmobile engines in my time. Many of there models like there triple
> cylinder 600, 700, and 800cc motors have a cage less bearing with spacers on each side of the rod to keep the needles from coming out to far.
> ...


----------



## mtngun (Feb 23, 2010)

leeha said:


> I have worked on and rebuilt many Ski Doo snowmobile engines in my time. Many of there models like there triple
> cylinder 600, 700, and 800cc motors have a cage less bearing with spacers on each side of the rod to keep the needles from coming out to far.


Lee, what material is used to make those spacers ?

Brad, thanks for the detailed information and great pics. I still don't foresee a forged piston in my future, but the technology is interesting nonetheless.


----------



## lone wolf (Feb 23, 2010)

blsnelling said:


> Here's the low down on the 440 piston. Distance between the pins is fine, but they're 2mm off center. My measurements show a 1mm difference between pins, but that's a stong 39mm. I can't measure much closer than that with what I have. So it's probably within .5mm. Reguardless, that's not a problem at all. The distance between pin bosses is within .006". Notice the wider skirt width on the Wiseco


call or email them and see what the heck is the reasoning for this.


----------



## blsnelling (Feb 23, 2010)

lone wolf said:


> call or email them and see what the heck is the reasoning for this.



It's all posted above. Gregg is working this out with Wiseco. They have confirmed that the engineering documents have them centered off the centerline at a 45° angle. So they're definately defective.

BTW, quoting all the pictures tends to make the thread hard to read. Thanks


----------



## Meadow Beaver (Feb 23, 2010)

Brad, I see the Wiseco skirt is wider on the 440, is it any wider on the 660?


----------



## kevlar (Feb 23, 2010)

leeha said:


> blsnelling said:
> 
> 
> > With that said, I'd like to dig a little deeper into this. Have you seen sled engines where the bearing actually comes partially out of the rod? I understand that the bearing floating left and right is a non issue. I understand that the rod stays centered between the pin bosses. Do the sled engines use spacers to limit bearing travel?
> ...


----------



## blsnelling (Feb 23, 2010)

StumpStomper said:


> Brad, I see the Wiseco skirt is wider on the 440, is it any wider on the 660?



It is, but it's together where I can't measure it right now.


----------



## blsnelling (Feb 24, 2010)

The 066 is running. I've put about 1 tank through it. Compression is 150 PSI. Videos and comments here.


----------



## leeha (Feb 24, 2010)

Brad, What type of breakin did you
do with this piston kit.
I wouldn't have thought all the machining
lines would be worn off this early.



Lee


----------



## blsnelling (Feb 24, 2010)

leeha said:


> Brad, What type of breakin did you
> do with this piston kit.
> I wouldn't have thought all the machining
> lines would be worn off this early.
> ...



I started and warmed it up several times with a cool down between. Only after the 3rd or 4th time did I rev it enough to put a tach on it. I then put it in the wood as seen in the Ash videos. I'd make a cut and then let it idle for a few seconds between cuts. It wasn't extensive, but perhaps a little more than I normally would. I've never seen one wear this much though. However, the piston is perfectly smooth with no smearing or scoring at all. I'll probably have it back off shortly and get some pics of it.


----------



## indiansprings (Feb 24, 2010)

Good video Brad, saw sounds good. That hard oak is the world we live in.
I chalk up the great performance to those sexy holes in the air filter cover!lol
I know you got it that way, couldn't help but notice those. It'll be interesting to see how it looks after some serious useage. I don't think the sideplay is an issue as long as the needles aren't exposed, if they were it would be a different issue. Glad it worked.


----------



## Paul001 (Feb 24, 2010)

I'm still interested in knowing the context of the quote you provided. Who's lead engineer brought up the issue? Wiseco or Baileys? It's wonderful they are now figuring out that spec's were not followed, would be interesting to know how the first run got past Q/C.

Sounds like a lot of Bill Clinton speak with regards to these issues.

Hopefully they get it sorted out and Baileys is able to manage the customer relations side of things.


----------



## blsnelling (Feb 24, 2010)

The filter was quite clean after nearly a full tank, perhaps cleaner than normal. These do like to cake up but work well in spite of it.

I'm going to put a degree wheel on it tonight. I did not alter port timing the first time round. I only widened and shaped the ports. Depending on what I find, I may or may not do some more port work. If nothing else, I want to see the piston, and check up on the bearing deal. Hopefully the new bearing will show up before I'm ready to go back together.


----------



## blsnelling (Feb 24, 2010)

Paul001 said:


> I'm still interested in knowing the context of the quote you provided. Who's lead engineer brought up the issue? Wiseco or Baileys? It's wonderful they are now figuring out that spec's were not followed, would be interesting to know how the first run got past Q/C.
> 
> Sounds like a lot of Bill Clinton speak with regards to these issues.
> 
> Hopefully they get it sorted out and Baileys is able to manage the customer relations side of things.



I *think *it was Wisecos engineer that brought up the bearing issue. I'm not 100% sure on that though. Gregg would have to answer that.


----------



## indiansprings (Feb 24, 2010)

If it keeps the filter cleaner, it may be the mod of the future. You'll have three hundred people experimenting with what size holes and angle of the holes work best.lol I've run the 660 with the filter cover off and it doesn't seem to be as dirty, just depends what your doing.

What rpms were running no load? I think I've got mine too fat.


----------



## blsnelling (Feb 24, 2010)

indiansprings said:


> What rpms were running no load? I think I've got mine too fat.



As you saw, I was playing around with it quite a bit. I was seeing from 13,500-14,200. It seemed to be getting faster as I went, requiring me to keep richening it up. It'll probably continue to do that as the saw breaks in. I believe spec on a stock 066 is 13,000.


----------



## kevlar (Feb 24, 2010)

looks good Brad! So what's she feel like- possible a little torquier from the heavier piston, didn't seem any slower to spool up.


----------



## blsnelling (Feb 24, 2010)

kevlar said:


> looks good Brad! So what's she feel like- possible a little torquier from the heavier piston, didn't seem any slower to spool up.



RPMs aren't what I hoped for in a ported saw. I don't know if the weight of the piston is playing a factory or not. That's why I'm going to put a degree wheel on it.


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## leeha (Feb 24, 2010)

blsnelling said:


> I started and warmed it up several times with a cool down between. Only after the 3rd or 4th time did I rev it enough to put a tach on it. I then put it in the wood as seen in the Ash videos. I'd make a cut and then let it idle for a few seconds between cuts. It wasn't extensive, but perhaps a little more than I normally would. I've never seen one wear this much though. However, the piston is perfectly smooth with no smearing or scoring at all. I'll probably have it back off shortly and get some pics of it.




Sounds like you broke it in ok. I think i would have done a couple light cuts then let it completely cool and repeat a couple times. According to Wiseco it is important to do a few heat cycles so the piston will take shape to the cylinder.
Your .0015 - .002 piston clearance might be a bit tight for a forged piston. Wiseco and myself decided to with 
.003 - .0035 on the 166 pistons we did. But the 166 is also a 56mm bore. I'm sure the 066 must be a bit smaller.


Lee


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## blsnelling (Feb 24, 2010)

leeha said:


> According to Wiseco it is important to do a few heat cycles so the piston will take shape to the cylinder.



Which indicates to me that they're expecting more break-in wear than we're used to.



leeha said:


> Your .0015 - .002 piston clearance might be a bit tight for a forged piston. Wiseco and myself decided to with
> .003 - .0035 on the 166 pistons we did. But the 166 is also a 56mm bore. I'm sure the 066 must be a bit smaller.



That was at the very bottom of the skirt. It was significantly smaller than that at the crown.


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## mtngun (Feb 24, 2010)

blsnelling said:


> I'm going to put a degree wheel on it tonight. I did not alter port timing the first time round. I only widened and shaped the ports.


This dataholic would enjoy seeing yet another set of 066/660 port timing data. 

Thanks as always for your detailed reports, Brad.

Paul001, I don't want to publicly embarrass our sponser, and I don't know what goes on behind the scenes in spec'ing these products -- but I can guess, having done some design and outsourcing in one of my previous careers. 

Manufacturing is a new thing for Bailey's. They recently hired a QC guy, but I doubt if they have a technical designer per se. They are probably relying heavily on their vendor's design expertise. Until recently it appears they mostly cloned OEM specs and didn't get too creative except for enlarging cylinder bores.

One can imagine the discussion going on now between Bailey's and Wiseco, with each pointing a finger at the other. It happens all the time when you are working with vendors and contractors.

I've said it before, and I'll say it again, the Bailey's products are gradually getting better, and I appreciate them giving us more choices. This forged piston idea was a big step for them, maybe a little too big. I am still optimistic that things are getting better, and the bottom line is that thanks to Baileys, we have many choices now that we didn't have before.


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## Grande Dog (Feb 24, 2010)

Howdy,
In this particular case we supplied Wiseco with the OEM samples. Right now, it sounds like they had the specs right (45 degrees off center line) for the pins but, the indexing jig must have been off the center line of the piston. So the pins did end up being 90 degrees apart, just not on center. I'm still waiting on the disposition.
Regards
Gregg


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## Paul001 (Feb 24, 2010)

mtngun said:


> This dataholic would enjoy seeing yet another set of 066/660 port timing data.
> 
> Thanks as always for your detailed reports, Brad.
> 
> ...



Having spent a portion of my life in a similar position as you, I agree.  Hence, part of the reasoning behind my loaded question.

I have no doubt that Baileys will handle the customer service issue better most anyone would. I'd like to see this project succeed if for no other reason than the ability to provide my customers (and me personally) with another reasonably priced option, besides OEM.


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## Bowtie (Feb 24, 2010)

Grande Dog said:


> Howdy,
> In this particular case we supplied Wiseco with the OEM samples. Right now, it sounds like they had the specs right (45 degrees off center line) for the pins but, the indexing jig must have been off the center line of the piston. So the pins did end up being 90 degrees apart, just not on center. I'm still waiting on the disposition.
> Regards
> Gregg



Thats odd of Wiseco to make an error like that. I ran their pistons in outlaw mini sprints in Colorado in the 90's and they were they racing piston producer to beat. I have also seen their products in other applications and for them to screw up like that puts them on par with Toyota's current SNAFU on a smaller scale.

That being said, I know they will fix it. Someone in QC needs walking papers.


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## matt9923 (Feb 24, 2010)

Bowtie said:


> Thats odd of Wiseco to make an error like that. I ran their pistons in outlaw mini sprints in Colorado in the 90's and they were they racing piston producer to beat. I have also seen their products in other applications and for them to screw up like that puts them on par with Toyota's current SNAFU on a smaller scale.
> 
> That being said, I know they will fix it. Someone in QC needs walking papers.



Iv had quite a few bikes with them. Usually good quality.


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## blsnelling (Feb 25, 2010)

Here are pics of the 066 Wiseco piston after 1 tank of fuel, as shown in the vids yesterday. As mentioned before, I warmed up the saw 4 times with complete cool downs before revving it enough to put a tach on it. I then started bucking about 20" logs with a few seconds of idle between to cool down.

This piston isn't hurt, but it appears to me that it's a little tight for the bore. Additional careful break-in will be in order.

The cylinder looks just like it did when I put it together. BTW, all ports were beveled and then the edges sanded by hand. I then check for snags with a ring.













I always get polishing immediately on the bottom of the intake skirt, but never anywhere near this much.







You can see wear near the crown about all the way around the piston.












Please ignore the little divot. That was a boo boo


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## mtngun (Feb 25, 2010)

blsnelling said:


> Please ignore the little divot. That was a boo boo


Glad I'm not the only one who makes boo-boos.

Thanks again for the detailed report.

You mentioned something about checking port timing ?


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## blsnelling (Feb 25, 2010)

Port timings are:

Exhaust 96°
Transfers 116°
Intake 81°

Very little port timing was changed during the initial porting. The intake may have been dropped 1°, that's it.


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## timberwolf (Feb 25, 2010)

That rubbing all the way around the crown is a sure sign of too tight a piston fit or too much heat. It was right on the edge of failure.

That rub up top tell that the piston crown grew due to thermal expansion from its cold measurment to the full diamiter of the bore. At little math and the average crown temperature can be worked out, assuming the rubbing occured before the bore reached full temperature and had no chance to expand adding to piston clearance (which was likely the case).


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## blsnelling (Feb 25, 2010)

I'm careful to warm a saw before putting it to work or reving much. Does this thing need to set and idle for 5 minutes or what? Perhaps it simple expands more than the cylinder. That's beyond my pay grade though, lol.


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## timberwolf (Feb 25, 2010)

I think this article covers the issue quite well.

http://www.docstoc.com/docs/14437665/Expansion-coeffficient-of-aluminum-%E2%80%93-Forged-vs-Cast

The main point is the silicon use to improve the castibility of cast pistons and cylinders for that mater also reduces the thermal expansion. Forged pistons simply change in size more with change in temperature and will require a little extra piston clearance and care in the warm up period.


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## Hddnis (Feb 25, 2010)

So, for this piston, should Brad take a little 1200 grit sandpaper to it until it has proper clearance for the cylinder he has?




Mr. HE


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## blsnelling (Feb 25, 2010)

I found this quote in the article interesting.

"Cast pistons give better long term wear in "normal" applications because the excess silicone hardens the surface.".

Sounds to me like a factory cast piston will give a longer service life in a chainsaw. The advange of the forged piston comes into affect under heavy abuse, perhaps as found in boosted applications.


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## blsnelling (Feb 25, 2010)

Hddnis said:


> So, for this piston, should Brad take a little 1200 grit sandpaper to it until it has proper clearance for the cylinder he has?
> 
> 
> 
> ...



I have some super fine grit. Perhaps I should run my ball hone through the cylinder, giving it a little more oil holding ability, and perhaps ever so slightly enlarging it?


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## blsnelling (Feb 25, 2010)

When measuring piston to bore clearance, where do you measure on the piston? There a big variance from crown, to below the rings, to the bottom of the skirt. Clearance at the skirt on this piston was less than .002".


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## Hddnis (Feb 25, 2010)

I have sanded in the past when I had really tight pistons. I would fold the sandpaper in a zig-zag pattern and then wrap it around the piston and turn the piston by hand. This basically made an internal flap wheel sander and seemed to work well for taking a very small amount off evenly. 

I could take a picture if you need.



Mr. HE


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## Jacob J. (Feb 25, 2010)

Hddnis said:


> I have sanded in the past when I had really tight pistons. I would fold the sandpaper in a zig-zag pattern and then wrap it around the piston and turn the piston by hand. This basically made an internal flap wheel sander and seemed to work well for taking a very small amount off evenly.
> 
> I could take a picture if you need.
> 
> ...



That's exactly what I do too. I got a Golf piston once that was too big for the bore so I spent the better part of an hour hand-sizing it and checking the clearance with a feeler gauge to get it within specs. I think this is the best way of re-sizing a slightly too large piston. 

Wiseco pistons have long been known to expand a lot due to the piston skirts and other areas being thicker overall. When I'm building the kart engines I have to spend a lot of time relieving areas inside the pistons to get them to a point where they won't cold seize.


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## blsnelling (Feb 25, 2010)

blsnelling said:


> When measuring piston to bore clearance, where do you measure on the piston? There a big variance from crown, to below the rings, to the bottom of the skirt. Clearance at the skirt on this piston was less than .002".



What clearance should I be looking for here on a 54mm bore, and where to measure on the piston?


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## leeha (Feb 25, 2010)

IMO, I would like to see .003 for that piston.
And check it at the bottom and half way up the skirt.
The crown is always much smaller.


Lee


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## Jacob J. (Feb 25, 2010)

leeha said:


> IMO, I would like to see .003 for that piston.
> And check it at the bottom and half way up the skirt.
> The crown is always much smaller.
> 
> ...



+1. On the Macs that are just slightly larger in bore diameter I usually shoot for .0035" to .0045" depending on the thickness and height of the piston. On the great big engines I might go a little more. The last West Bend 820 I put together with a Wiseco piston I went .0055" just because of the sheer size of the piston.


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## rxe (Feb 25, 2010)

Rather than sanding it, shouldn't this one be going back so that they can work out the pistons need more clearance?


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## blsnelling (Feb 25, 2010)

Careful measurement with my Brown & Sharpe dial calipers measures the bore at 2.1265". I know that's not the correct measuring device, but that's the best I have.

Here are piston measurements.

Very top edge - 2.116" / .0105" Clearance
Just below bottom ring - 2.120" / .0065"
Middle of skirt - 2.123" / .0035"
Bottom of skirt - 2.122" / .0045"

You can see how much the skirt has already worn.


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## leeha (Feb 25, 2010)

With dial calipers the part that hits the cylinder
is not sharp but is slightly flat and will give a false reading.
I would use a bore gauge or a good inside micrometer.



Lee


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## blsnelling (Feb 25, 2010)

leeha said:


> With dial calipers the part that hits the cylinder
> is not sharp but is slightly flat and will give a false reading.
> I would use a bore gauge or a good inside micrometer.
> 
> ...



These have a sharp edge, so it should be quite accurate.


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## Hddnis (Feb 25, 2010)

rxe said:


> Rather than sanding it, shouldn't this one be going back so that they can work out the pistons need more clearance?




My thoughts on this are no it should not go back. 

The reason is because not every cylinder is the same size. Brad might have one on the smaller side and that is why his piston is too big. You could get a saw with a cylinder on the larger size and the piston would be just right for you.

Even a factory piston should be checked for size and adjusted down if too large and a larger one used if too small. Usually the a factory piston, being cast and having larger clearences, can just go right in a you'll get away with it.



Mr. HE


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## blsnelling (Feb 25, 2010)

I decided to go ahead and give it a quick hone.


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## indiansprings (Feb 25, 2010)

Can't believe the amount of skirt wear, most I've seen for no more than you ran it. Even with the hone job, I'd be afraid of seizure with prolonged sustained cutting. Gonna have to be careful and let the saw warm up as you do before spooling up. Got anyone close with a lathe. Might be able to chuck it up and use a fine emery cloth with a little oil to remove very little material on the crown.


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## rxe (Feb 25, 2010)

> My thoughts on this are no it should not go back.
> 
> The reason is because not every cylinder is the same size. Brad might have one on the smaller side and that is why his piston is too big. You could get a saw with a cylinder on the larger size and the piston would be just right for you.



Hmmm. I see what you are saying...but there will be nominal "cold" size for both piston and jug. I would assume that Wiseco have got this right. The problem with these forged pistons is that they seem to expand far faster than the jug. Most people will not be like Brad, they will start up the saw and stick it in some wood - and get a cold seize. If these things need a bit more slop in them when they are cold, then the need to be a scratch narrower than the stock items. The damage to this piston is effectively "the evidence". 

Brad may have a narrow jug, he may not - that will need measuring (precisely) as well.


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## matt9923 (Feb 25, 2010)

:agree2:




Hddnis said:


> My thoughts on this are no it should not go back.
> 
> The reason is because not every cylinder is the same size. Brad might have one on the smaller side and that is why his piston is too big. You could get a saw with a cylinder on the larger size and the piston would be just right for you.
> 
> ...



In reality very few people know how to do this and never measure anything, they just pop it in an go. If they are in fact to big I think Baileys is goign to start having problems. Just my thoughts.


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## Mad Professor (Feb 25, 2010)

Did Wiesco ever RUN these slugs in saw?

Or just make them and let come what be?


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## blsnelling (Feb 25, 2010)

Mad Professor said:


> Did Wiesco ever RUN these slugs in saw?
> 
> Or just make them and let come what be?



Kind of looking that way isn't it? These are going to have to be drop in reliable if they're going to be a success.


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## Mad Professor (Feb 25, 2010)

Fit may get even trickier if they make them for the older saws with "A" and "B" size cylinders.

The meteor site lists several size slugs for each model and they suggest you mic the cylinder before ordering. If I remember correctly they vary by 0.01 mm (ca. 0.0004").


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## leeha (Feb 25, 2010)

Mad Professor said:


> Did Wiesco ever RUN these slugs in saw?
> 
> Or just make them and let come what be?



From Wiseco's Rep who i delt with.
We don't manufacture pistons for chainsaws.
We need to know the original piston clearance.
What temp they may get up to. They need to know
these things to help with there enginering dept.
so there won't be any failures. There forged pistons
have a much different expansion rate than a cast
piston. In my experience forged pistons always need
more clearance no mater what the engine is.
I don't believe Wiseco would manufacture a piston 
and just throw it in someones lap without knowing some spec's. If the information that was given to Wiseco was incorrect then any failures would be in the lap of the original person who placed the order.


Lee

Lee


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## Tzed250 (Feb 25, 2010)

blsnelling said:


> These have a sharp edge, so it should be quite accurate.





The accuracy of calipers when used like that is about the same as the clearance, making them unsuitable for determining the clearance in that application.


.


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## AUSSIE1 (Feb 25, 2010)

I would of thought an air cooled 2 stroke would have too much of a temperature variance for a forged piston.


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## matt9923 (Feb 25, 2010)

Tzed250 said:


> The accuracy of calipers when used like that is about the same as the clearance, making them unsuitable for determining the clearance in that application.
> 
> 
> .



what is a reasonably priced bore gauge?


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## Tzed250 (Feb 25, 2010)

matt9923 said:


> what is a reasonably priced bore gauge?



The set seen here can be had for about $100. A 2-3" micrometer will be needed too. 


.


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## matt9923 (Feb 25, 2010)

Tzed250 said:


> The set seen here can be had for about $100. A 2-3" micrometer will be needed too.
> 
> 
> .



where can you buy em?


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## blsnelling (Feb 25, 2010)

Here's the piston polished up. There are no signs of the scuffing. According to the calipers, I didn't really remove anything, just polished it up.


This is the intake side the had the worst wear.








And the exhaust side.


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## matt9923 (Feb 25, 2010)

blsnelling said:


> Here's the piston polished up. There are no signs of the scuffing. According to the calipers, I didn't really remove anything, just polished it up.
> 
> 
> This is the intake side the had the worst wear.
> ...



How did you polish it?


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## blsnelling (Feb 25, 2010)

matt9923 said:


> How did you polish it?



600 grit. I decided not to go any finer. Pistons purposely have the "machined lines" in them, supposedly to carry oil. It took very little to polish it up, since there was no real scoring, just some minor scuffing.


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## indiansprings (Feb 25, 2010)

Leeha, I agree with your train of thought. Bailey's is a great company with an excellent service record, but they seem to need a trained engineer on staff to communicate the spec's of engine components. It's a specialized task, if they are using anyone other than someone who has specialized training in this field then they are asking too much of the individual and placing the customer potenially at risk. I wouldn't ask a saw mechanic to do it, as good as one may be, there's alot more to it than meets the eye, the communication and language between engineers, whether it be software, civil, mechanical or whatever is usually different than what someone outside the field would be in my observations of product development processes.


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## swerner (Feb 25, 2010)

matt9923 said:


> where can you buy em?



Enco or MSC industrial supply will have them. The easiest way to set a dial bore gauge is with a ring gauge or gauge blocks with ends. A micrometer will do, it just takes longer. Companies like Sunnen make fancy bore gauge setting machines that are real easy to use, although very cashy.


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## Tzed250 (Feb 25, 2010)

swerner said:


> Enco or MSC industrial supply will have them. The easiest way to set a dial bore gauge is with a ring gauge or gauge blocks with ends. A micrometer will do, it just takes longer. Companies like Sunnen make fancy bore gauge setting machines that are real easy to use, although very cashy.



Ring gages are expensive and you will need the mic to measure the piston.


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## Mad Professor (Feb 25, 2010)

swerner said:


> Enco or MSC industrial supply will have them. The easiest way to set a dial bore gauge is with a ring gauge or gauge blocks with ends. A micrometer will do, it just takes longer. Companies like Sunnen make fancy bore gauge setting machines that are real easy to use, although very cashy.



Snap gauge for the bore and measure that with a precision Mic, the same one used for the piston.


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## howellhandmade (Feb 25, 2010)

indiansprings said:


> Leeha, I agree with your train of thought. Bailey's is a great company with an excellent service record, but they seem to need a trained engineer on staff to communicate the spec's of engine components. It's a specialized task, if they are using anyone other than someone who has specialized training in this field then they are asking too much of the individual and placing the customer potenially at risk. I wouldn't ask a saw mechanic to do it, as good as one may be, there's alot more to it than meets the eye, the communication and language between engineers, whether it be software, civil, mechanical or whatever is usually different than what someone outside the field would be in my observations of product development processes.



Not to mention, if something bad happens and there's not a Professional Engineer signature on it really would be unfortunate for Bailey's.

Jack


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## mtngun (Feb 26, 2010)

Tzed250 said:


> The accuracy of calipers when used like that is about the same as the clearance, making them unsuitable for determining the clearance in that application.
> .


Brass feeler gages can be used to measure skirt-to-bore clearance. They don't cost much and don't require a lot of skill to use.


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## blsnelling (Feb 26, 2010)

I put another tank of fuel through it this afternoon and pulled it back apart. It's still trying to scuff a little, but nothing like it was before. I'm going to get a little more aggressive with the land above the top ring since that's where most of it's occurring. I'm not impressed so far.


Intake












Exhaust


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## blsnelling (Feb 26, 2010)

This was freshly honed last night, with no marks. It's still not hurt. You can't feel any of this.


Intake












Exhaust


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## blsnelling (Feb 26, 2010)

BTW, here are a couple shots of the pin bosses. It looks like the bearing is staying in the rod.


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## blsnelling (Feb 26, 2010)

Here's video of todays cutting with it. *VIDEOS*


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## HARRY BARKER (Feb 26, 2010)

what is "really hard oak"???


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## blsnelling (Feb 26, 2010)

HARRY BARKER said:


> what is "really hard oak"???



Oak that when your friends cut it say, man, that stuff is as hard as a rock, lol


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## Tzed250 (Feb 26, 2010)

mtngun said:


> Brass feeler gages can be used to measure skirt-to-bore clearance. They don't cost much and don't require a lot of skill to use.



LOL....that is what you do when you don't have the right tools...


.


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## FATGUY (Feb 26, 2010)

blsnelling said:


> Oak that when your friends cut it say, man, that stuff is as hard as a rock, lol



yup, been threre, said that.


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## matt9923 (Feb 26, 2010)

blsnelling said:


> Oak that when your friends cut it say, man, that stuff is as hard as a rock, lol



That rock oak is all I cut, mostly. When I get to pine I just smile.


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## parrisw (Feb 26, 2010)

Brad, you do your best work on your knees!!:jawdrop:


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## Freakingstang (Feb 26, 2010)

parrisw said:


> Brad, you do your best work on your knees!!:jawdrop:



WOW.........

Funny as hell, but WOW


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## parrisw (Feb 26, 2010)

Freakingstang said:


> WOW.........
> 
> Funny as hell, but WOW



ha ha ha. I thought so. Hopefully not too outa line!!


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## Freakingstang (Feb 26, 2010)

ooops double post


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## mountainlake (Feb 27, 2010)

HARRY BARKER said:


> what is "really hard oak"???



That looks like white oak. Steve


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## matt9923 (Feb 27, 2010)

Mad Professor said:


> Fit may get even trickier if they make them for the older saws with "A" and "B" size cylinders.
> 
> The meteor site lists several size slugs for each model and they suggest you mic the cylinder before ordering. If I remember correctly they vary by 0.01 mm (ca. 0.0004").



I don't see Baileys offering different ones? I got one here and its pretty tight .0015" in some spots.


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