Wiseco Piston Pics and Comments

[blsnelling]

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.

 

[Stihl088stock]

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!

 

[parrisw]

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.

 

[blsnelling]

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.

 

[blsnelling]

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.

 

[kevlar]

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.

 

[Justsaws]

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.

 

[parrisw]

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

 

[parrisw]

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?

 

[kevlar]

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?

 

[parrisw]

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.

 

[teacherman]

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).

 

[Jacob J.]

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...

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...

 

[AUSSIE1]

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.

 

[Jacob J.]

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.

 

[rxe]

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.

 

[WoodChuck'r]

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!!

 

[wigglesworth]

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:

 

[mdavlee]

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

 

[hotshot]

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)