Stihl 026/260 mods and porting

danschweitzer

I just want to thank you boys for all the info especially windthrown for the pictures and info on 2 stroke engines and just in general my 2 026s have both got more power now after simple muffler mods more torque aswell I gues I found all this out at a bit of a cost though. You ll come away the better for it. I think it was me who made an inquiry in the first place from the husky thread, sorry! I ll be a bit more carefull next time

danschweitzer

I ve just realised that alot of the info came from Bruce and therfor thanks aswell!!

Eric Frei

OK, I have nailed a bunch of posts, posts which also quoted nailed posts got removed.

Any more, please speak up now.

__________________

Cut4fun

Thanks Eric for cleaning up my post for me. Now if this windthrown guy can just stay on track with the 026-260 thread.

TreeCo

Some are here to share chainsaw mod information and some are here to run interference with that info. Looks a lot better cleaned up.

__________________
Grow more vegetables!

Cut4fun

I guess you missed I am the one that ask to clean up the thread and remove my distracting post.


Now stay on track Dan or we will sick the on you. This is a 026 260 thread not your personal gripe thread .

So whats the cheapest you guys have seen OEM 026 pistons for lately?

windthrown

You guys better watch it or I will take up the offer to become a mod!

Ain't no such thing as "cheap OEM Stihl". I would get a Meteor piston kit. Cheapchainsawparts has new OEM 026 piston and rings listed on Ebay for $50. Baileys has OEM 026 piston/ring kids for $125 *cough* (Meteor kits there are $35). There was a guy on Darin's forum that was selling complete new OEM 260 P&Cs for less than $100. He was one of my evil enemies over there though, so I got the last 260 OEM P&C that Andy (AKA: Lakeside) had on hand instead, along with a beater 026 carcass that I re-ringed, ported and turned into a little screamer. The scored 026 that I had now has Andy's new OEM 260 44.7mm P&C (poor man's "baby big bore" kit). That saw runs great.

Cut4fun

Thanks for the info.

But I hate to tell I am not scared of no mod's. Most let their heads feel full of air and get booted themselves . Never been booted from my mods job on a chainsaw site of a couple years now .

danschweitzer

Bin in woods today with 026 15 inch bar cutting mainly larch close to same speed as 357 husky. agree about a bit of back presure mind have an idea will try it, if it works can post pics Its suprising wat a quick muffler mod can do hey

Jeff Darby

Well that good your not scared of us mods, after all we are members too...dont forget that.

Our job here is to keep threads on track and free from personal grievences, so anyone can tune in and have a good read, how ever if the situation warrants the action we have the authority to ban members for life if needed.

Anyway I thought I would just post this so every one concerned could see that all of us mods, thats right theres a number of us who help keep this place tidy and a friendly place to talk have more than just hot air whistling between our ears, we are members aswell with a tough job to do, when it come to a judgment call and they are not taken lightly or executed from an egotisical point of view.

Happy New Year guys

JayD

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Join the Australian Tree Association...Have your voice heard !

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© Jeffrey J Darby 2011

Cut4fun

Post the whole post . You left some out.

Happy New Years all.

terry

Hi guys,
I don't know anything about modified saws,but on race engines some back presure is needed for low end torqe,on the other hand top fuel drag cars run with no back presure as their throtle is wide open from start to finish.On that asumption a work saws need back presure and a race saw dosen't.

windthrown

Different types of engines: saws are mainly 2-strokes (but some new ones are 4-mix 4-strokers). Dragsters (and most cars) are 4-strokes. 4-stroke engines have intake and exhaust valves to keep fuel and exhaust from leaking out of the combustion chamber through the ports, so no back pressure is needed for the exhaust. All 2-strokes need some back pressure to keep the fresh fuel inside the combustion chamber. Racing 2-strokes typically have tuned expansion pipes that use pressure waves that bounce off the bipe body to push fresh fuel leaking out the exhaust port back into the cumbustion chamber before the exhaust port is closed by the upward travel of the piston.

Cut4fun

That's only true for the piped class and hotsaws.

90% of the race saws run a muffler in the stock appearing classes. 3ci 4ci 5ci 6ci 6ci+ and mufflers are wide open.

terry

Thanks for the info Terry.

windthrown

Well, to me hotsaws and pipes saws are the racers. My point is that 2-strokes have some sort of device for providing exhaust back pressure, racing or not (pipes or muffler shells). Piped racing saws (and motorcycles) look open, and they are from the perspective of visibility. However, they provide a back pressure wave when they are tuned properly on a saw or bike (or bike saw). This is to force unburned fuel mix that follows the exhaust gasses out the exhaust port back into the combustion chamber above the piston before the exhaust port closes.

This is opposed to a 4-stroke racing engine that also has open headers from the perspective of visibility. 4-stroke racing engines with headers are usually tuned the opposite of 2-stroke pipes though. They are tuned to produce a negative back pressure wave. That pressure wave creates a partial vacuume before the exhaust valves close in order to suck out more of the exhaust gasses. If you also time the intake valves to open just before the exhaust valves close, this negative pressure wave from the exhaust headers also helps to pull in more fuel mix into the cylinder.

In a nutshell, 4 stroke racing engine exhausts are typically tuned the opposite of 2-stroke racing engine exhaust systems when it comes to back pressure. Racing being somewhat arbitrary here.

Clear as mud?

Cut4fun

I take you dont race or hang out at races much.

Here is one show with 5 classes. 3 muffler 2 pipe.

Then other shows are 6 classes with only 1 piped class.

http://tiny.cc/AT5Tk

windthrown

Nope. I typically avoid the big races, cars, bikes and saws these days. They are zoos and the media is there with lots of screaming kids and all. Same with the logging shows and conventions in Eugene these days, as well as the fairs. I worked at too many fairs, and saw too much BS for one lifetime. If I do go these days I only show up and watch the hotsaw and bikesaw stuff, and the demos of the V8 monsters. Two hours is about my limit at such places. Well maybe with an hour in the beer garden makes three.

When I was a kid we used to go to all the logging, boat shows and fairs, and that was mostly axes and hand saws, with a few all-out piped demo saws. I like what looks like piped Stihl 260s in that video though.

Cut4fun

No piped 260's. The piped class was 5 cube like 460 181 281 etc and hotsaws.

Getting some info for you from the guy I use for pipe builds now days. Being the guys that built my other 3 pipes no longer build saws etc.

Cut4fun

Were talking race saws here. Info from a pipe builder and saw builder.



The Husky 50 race saw I built and you seen race and is top of class, it had zero back pressure on a muffler saw. Nothing, if it weren't for the piston you could look right through the saw.

For efficiency and good low speed operation yes some back pressure helps, but when the chips are down a 2 stroke motor is a pump and the more air it pumps the more fuel it can burn and more power it can make. Any restriction on the inlet or outlet of the pump will lower the amount it can pump and by that the ultimate power it can produce.

A pipe is different than simple back pressure as it can both suck and blow the charge out of the cylinder and back into it allowing the cylinder to be filled with more than 100% its volume of uncompressed charge.

Often guy that mess with motors a bit esp bikes and sleds find that squeezing the stinger down makes for more speed and on a lightly modded motor with stock pipe it likely does. However it is not because increased back pressure is doing something good, but because of the increased pipe temperature which effectively shortens the pipe and raises the power band and peek HP RPM.

Willard Holmen

Good posts cut4fun.
In 3 weeks time my chainsaw competitons that I sponsor and organize is coming up quickly. I am right in the middle of rounding up competitors and getting things ready to help celebrate our 2010 Northern Manitoba Trapper's Festival. Google www.trappersfestival.com
I took the last 3 festivals off and now have new enthusiasm after seeing the last director almost run the competition into the ground, by not running the speed cutting events and not bringing in the pros to compete in the timed carving event.
So I don't have time to get too heavily involved in a thread at the moment, but after 3 weeks time I'm going to start a "Racing sawchain secrets" thread.
My advice here to all readers on Tree World is enter a organized chainsaw speed cutting competiton. You will never be sorry for doing it. Sitting on the sidelines of a timbersport or saw competiton is no where near the fun of hands on competition.
Willard.

Bruce Hopf

Since I joined web sites like this one here, I didn't know too much about races, for chain saws of any kind.
Since I joined web sites like this one here, I've learned a lot, and a lot more to learn.
Thus far, I've only done muffler modifications, to my chain saws, and my nest step, will be porting. I've picked up another 044, that presently is all stock.
Once I have a nice day (weather hasn't been all that nice here), I'm going to do some test cuts, between stock muffler, and modified muffler. I'll be making videos, of both cutting with the stock, and modification, and putting them on You Tube, and post the link to it here, that way I can share with everyone here.
I also have another 034, that presently is stock, and I'll be doing the same thing with it, doing test cuts with the stock muffler, and the modified muffler, and making videos as well of cutting with stock, and modification, and as well as putting the4m on You Tube, and I'll post the links for it as well here.
I'm sending pioneerguy600, the cylinder off of my 044, along with a parts chain saw that he was looking for, and found for him, and he is going to the porting of it for me.
Reason I'm getting pioneerguy600, to do the porting for me, for my 044, is that I don't have an extra cylinder for the 044, like I do for my 024, and 034. So if I screw up with porting the cylinder, for the 024, and the 034, I'm not out a chain saw to work with, and won't have to replace a cylinder.
Once I get my ported cylinder back from pioneerguy600, and back on the chain saw, I'll be doing test cuts again, and making a video of the chain saw again, to see the difference between all the stages of modification, of the chain saw. I'll also be putting it on You Tube, and once again, provide the link to it, to share with everyone here.
If I like the outcome of the cylinder porting, for my 044. I'll definitely give porting a go on my own, with the extra cylinders for my 024, and 034, that I have on hand, and see how I do with it. I know that there is a lot to learn, about porting, and with the knowledge of the few guys, that actually have done a lot porting, that I have met on these web sites, I'm quite sure, and confident, that I can do it successfully, along with their coaching, and guidance. Thanks. Bruce.

__________________
McCulloch chain saws
1- Pro Mac 60, 1- Pro Mac 700, 2- Mac 10-10 Automatic's, 2- Mini Mac 30's, 2- Mac 110's,
2- Mini Mac 35's, 1- Mac 140 with Automatic Chain Sharpener,
1- Pro Mac 10-10, 1- Mac Cat, 2- Eager Beaver
2.0's, 1- Mac 1-10
Stihl chain saws
2- 044's, 2- 034's, 2- 024's, 1- 064, 1- 084,
Strunk chain saws
1- Busy Beaver, 1- SpeeDemon Special
Stand Back, I Have A Very Extreme Case of CAD (Chain Saw Addiction Disorder).

Bruce Hopf

Here is a link, to a thread I started, in regards to the stock muffler, and modified muffler for my 044, and links provided there to You Tube. Stihl 044, with Stock Muffler, and Modified muffler. . Thanks. Bruce.

__________________
McCulloch chain saws
1- Pro Mac 60, 1- Pro Mac 700, 2- Mac 10-10 Automatic's, 2- Mini Mac 30's, 2- Mac 110's,
2- Mini Mac 35's, 1- Mac 140 with Automatic Chain Sharpener,
1- Pro Mac 10-10, 1- Mac Cat, 2- Eager Beaver
2.0's, 1- Mac 1-10
Stihl chain saws
2- 044's, 2- 034's, 2- 024's, 1- 064, 1- 084,
Strunk chain saws
1- Busy Beaver, 1- SpeeDemon Special
Stand Back, I Have A Very Extreme Case of CAD (Chain Saw Addiction Disorder).

danschweitzer

Bin tryin to work this out so hope i can get thesae images on otherwise forhive me. well I ll just try

mastermind7864

That 044 of yours is looking real good Bruce, I've been following Jerry's build. Come to think of it you should have it back by now right? How does that bad boy cut?

Bruce Hopf

I was talking with Jerry earlier, via email, and he has put it in (now) Yesterdays mail. I can't wait till it get here (kind of like a kid in a candy shop), once I get it all back together again, and running, I'll post another video of it, in action, cutting fire wood . Bruce.

__________________
McCulloch chain saws
1- Pro Mac 60, 1- Pro Mac 700, 2- Mac 10-10 Automatic's, 2- Mini Mac 30's, 2- Mac 110's,
2- Mini Mac 35's, 1- Mac 140 with Automatic Chain Sharpener,
1- Pro Mac 10-10, 1- Mac Cat, 2- Eager Beaver
2.0's, 1- Mac 1-10
Stihl chain saws
2- 044's, 2- 034's, 2- 024's, 1- 064, 1- 084,
Strunk chain saws
1- Busy Beaver, 1- SpeeDemon Special
Stand Back, I Have A Very Extreme Case of CAD (Chain Saw Addiction Disorder).

Bruce Hopf

Today the parts that Jerry built for me, had arrived in today's mail. I've had the flue for a couple of days, and I haven't had a chance to look at everything, as of yet.
I'll be posting a link for YouTube once I get the chain saw up and running. Hopefully in a day or two, I'll be feeling better. Bruce.

__________________
McCulloch chain saws
1- Pro Mac 60, 1- Pro Mac 700, 2- Mac 10-10 Automatic's, 2- Mini Mac 30's, 2- Mac 110's,
2- Mini Mac 35's, 1- Mac 140 with Automatic Chain Sharpener,
1- Pro Mac 10-10, 1- Mac Cat, 2- Eager Beaver
2.0's, 1- Mac 1-10
Stihl chain saws
2- 044's, 2- 034's, 2- 024's, 1- 064, 1- 084,
Strunk chain saws
1- Busy Beaver, 1- SpeeDemon Special
Stand Back, I Have A Very Extreme Case of CAD (Chain Saw Addiction Disorder).

danschweitzer

I know none of you will respond to this but any way thanks to some good info and my friend showing me how to re size these pics I thought I d share them. When tuned right this saw is alot more economical on fuel and has a good bit more all round power,so thanks for shareing but as I know dont feel inclined to respond to this as that would be some thing out of the normall. iff no one does it was my last post here so thanks once again

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Bruce Hopf

Hi Dan.
That is a different way of doing things as well. Did you by chance, take some before video, and after the modification video? Would be nice to see as well.
Good job anyways. Bruce.

__________________
McCulloch chain saws
1- Pro Mac 60, 1- Pro Mac 700, 2- Mac 10-10 Automatic's, 2- Mini Mac 30's, 2- Mac 110's,
2- Mini Mac 35's, 1- Mac 140 with Automatic Chain Sharpener,
1- Pro Mac 10-10, 1- Mac Cat, 2- Eager Beaver
2.0's, 1- Mac 1-10
Stihl chain saws
2- 044's, 2- 034's, 2- 024's, 1- 064, 1- 084,
Strunk chain saws
1- Busy Beaver, 1- SpeeDemon Special
Stand Back, I Have A Very Extreme Case of CAD (Chain Saw Addiction Disorder).

danschweitzer

Did nt but this is close to same speed as 357 xpt and these are quite a bit heavier i can use myn all day think i de be cramping up with the husky it is a powerfull saw though that has to be said. I might get round to a vid one day but it has good all round power perfect with the 15 inch bar. Just wandered caus I baut an 8 tooth rim sprocket for the front but did nt think that the chain would nt fit it how many more links i ll need from 57. just one?

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