Question about Woods Porting?

[blsnelling]

I've done a ton of muffler mods using the deflector with sheetmetal screws. I've yet to have a problem with them coming out. If they are, I'm not hearing it back from my customers.

 

[gink595]

yes, but it looks like a hack did it!!!!

It does, it really does

 

[Tzed250]

.


Here we go....


.

 

[timberwolf]

880 is a pig. I'd rather have a 3120.

LOL yes 880 is a pig but the 3120 is just a pig covered in orange lipstick.

A properly ported 660 will eat up an 880 in anything but the largest wood and even paying top dolar for the port work a ported 660 will be less than the sticker shock of an 880. Same could be said for a ported 395 vs a stock 3120.

 

[pops21]

opcorn:

 

[gink595]

LOL yes 880 is a pig but the 3120 is just a pig covered in orange lipstick.

A properly ported 660 will eat up an 880 in anything but the largest wood and even paying top dolar for the port work a ported 660 will be less than the sticker shock of an 880. Same could be said for a ported 395 vs a stock 3120.

I have both and I will say that is spot on, My 066 has a stock cylinder and it is much more pleasant to run, I think I perfer it for milling too over the 880, at this point I'm not really sure what to do with the 880.... Maybe Hotsaw it, at least it would get used

 

[pops21]

Ok so I'm stumped on how wide you can open the exhaust and intake. I've heard no more then 30% of the bore. So my 288 is 54mm in diameter.

54mm x 3.14(PI) = 196.56mm diameter

196.56 x .30 (30% of bore) = 50.86mm

So I can't go no wider then the width of the piston skirt minus 2mm on each side or 50.86mm since its 30% of the bore. Which ever has the smallest length is the one I should go with?

Is this correct?

 

[mdavlee]

70% of bore or around 36mm or whatever that converts to in inches. Or whatever the piston skirt will cover up. How wide is the piston skirt?

 

[pops21]

I'm heading home for supper so I will let ya know in 30 min. How did you come up with 36mm.:monkey: Math was my worst school subject.

 

[mdavlee]

54x.7=37.8 36 was real closse. I did that in my head as thats 2/3 or 66.6%

 

[AUSSIE1]

If you go wide and especially increase the inlet duration, bring the port floor up a bit at the sides. If you look at the skirt on those pistons at the bottom there is like little cutouts either side. If you go wide without bring the sides up a little, those cutouts will open before the centre lower portion of the skirt. If you set the inlet floor for a particular duration and that area either side opens early, you have effectively increased the duration beyond what you were aiming for.

 

[pops21]

If you go wide and especially increase the inlet duration, bring the port floor up a bit at the sides. If you look at the skirt on those pistons at the bottom there is like little cutouts either side. If you go wide without bring the sides up a little, those cutouts will open before the centre lower portion of the skirt. If you set the inlet floor for a particular duration and that area either side opens early, you have effectively increased the duration beyond what you were aiming for.

So your saying keep the oval shape of the port. That if I put more of a square shape on the port that the sides of the piston will open before the bottom does? I'm trying to picture what your saying. Oh and I measured the piston skirt on both IN and EX. Intake was 38.34mm and EX was 38.22mm. On the bottom of the transfers the is a abrutp ledge from the cylinder wall into the transfer. Can I knock the ledge down and make it a smooth transition into the transfer?

 

[AUSSIE1]

So your saying keep the oval shape of the port. That if I put more of a square shape on the port that the sides of the piston will open before the bottom does? I'm trying to picture what your saying. Oh and I measured the piston skirt on both IN and EX. Intake was 38.34mm and EX was 38.22mm. On the bottom of the transfers the is a abrutp ledge from the cylinder wall into the transfer. Can I knock the ledge down and make it a smooth transition into the transfer?

Sorry mate, what saw is this on?

 

[pops21]

288xp

 

[AUSSIE1]

288xp

Sorry I was thinking 385/390.

They have the full circle piston. Well yeah just go wide mate.

 

[pops21]

Both the piston that was in the 288 and the meteor that I just got brand new are not a full circle piston. They have cut-outs.:monkey: Maybe you were talking about the 385/390 having a full circle piston. What about the bottom of the transfer? Can I grind that off to make a smooth transfer. I know the top of the transfer has to do with timing but not sure about the bottom.

 

[AUSSIE1]

Both the piston that was in the 288 and the meteor that I just got brand new are not a full circle piston. They have cut-outs.:monkey: What about the bottom of the transfer? Can I grind that off to make a smooth transfer. I know the top of the transfer has to do with timing but not sure about the bottom.

Yeah right. I fitted a 288 kit to the 181 but can't remember the piston type.
I had a look a the 181 piston and it's a full circle. I just had a look at the kits on Bailey's site.

Yeah you can open up the lower transfer taking that lip away also. The bottom doesn't have anything to do with timing.

A bit of reading for you.

http://www.arboristsite.com/showthread.php?t=129152

 

[parrisw]

Holy ****, I can't believe my one little comment started all of this!!!

Vegemite1,

I've got it worked out, no problem. Is a "working saw" in your mind, one that runs and is owned by a IT support specialist, or computer programmer? Sounds like it. I was describing a saw that is run for 8 hours a day felling trees 365 days a year. Cutting up firewood would require a "working saw", but how can you have time to do that and work on the computer 8 hours a day?
As far as the timing goes, that would require another post for explaination and pictures. Do a search...as everyone likes to say.

I'm done, goin to work. I just got on this thread because buddy told me that they were bashing D + D. This forum arguing is worthless......I'm outta here....

I never bashed Double D from the start and don't believe anybody else did.

All I did was say your not getting much for $90?? Is that so freakin hard to understand without getting your panties all wadded up???

The more I read about all the mods that can be done, I am thinking that less might be more in my case. For example, I am now thinking that all I may require is a simple muffler mod followed by the proper carb adjustment. This would in fact give my saw more power and help it run more efficiently and cooler would it not? Anyway, all the other expensive tweaking might not be necessary is what I am thinking. Plus, I am not crazy about shipping my saw across the freaking country and then having it shipped all the way back. If there was a local shop in my area that did this kind of work I would not even hesitate. But I don't really wanna trust UPS or Fed Ex, etc, etc, etc with the care of such an expensive saw when I am not exactly the richest guy in the world. Plus, the money I save on just doing the simple muffler mod and carb adjustment I figure I can put it towards another BIGGER saw and then do the same thing to it. Am I making sense here guys?

sounds like you don't need a modded saw at all. Most of the people here don't, they just do it for fun.

 

[Shrug]

Hey guys, I stopped at a Stihl dealership today and started asking some questions. It was not long before I realized that with the little knowledge that I had before I joined this site, plus the new knowledge that I have picked up from you guys already, that I knew way more than the salesman that was trying to sell me a saw. It was pretty amusing actually, I was asking questions about after market parts and talking about porting and what not, and the dude looked super confused. It is the only Stihl dealership near my house, and I will be buying a saw there in the near future, but they don't seem to know much. I am gonna have to order my saw because they don't carry anything big. I think I am gonna tell them to just leave it the way it comes and not even bother assembling it, I am kinda afraid that they will screw it up, haha.

 

[gink595]

All I did was say your not getting much for $90?? Is that so freakin hard to understand without getting your panties all wadded up???

It's hard to say unless you can see what they do, I don't see how people pay 250+ for some of the port jobs they get. I'd like to know what a guy really gets for his 250+, plus shipping. If I sent a saw out and got it back and it yields 15-20% I'd feel like I was farked really hard. I won't buy on that just because these fella's in Southern Indiana charging 90.00 aren't giving the same thing some of the "pro's" on the net are doing, anyone can grind ports wider, and drill holes in the muffler, it takes someone with some knowledge to start changing timing and making them go.