Modded Saws

shaggs · 14th November 2007, 01:56 AM

Hi All
Just thought I'd show a couple of pics of an old 036 stihl I did an exhaust mod on a few years ago.
Its just a piece of 19mm tube MIG welded to the exhaust and painted with high temp paint. It really did/has made a difference and I haven't had any prob with it. It's not the prettiest but it does work and holds WOT longer.

Anyone else modded any saws and noticed good gains or nil gains or problems?
I have also done 019's, 039, 066 but not the newer 361's as som say they dont respond as well.
Thanks EKKA for the help with the pic's.

Cheers

rsz_036mod1.jpg

rsz_036mod2.jpg

Quintrex · 14th November 2007, 02:26 AM

How much extra noise?

Tree Machine · 14th November 2007, 02:52 AM

More.

playfordtree · 14th November 2007, 04:24 AM

I haven't had much to do with modding saws Shaggs.
(Apart from ripping out those stupid spark arrestors.)

How does the pipe make a difference?
What does it do?
Is it like putting a sports exhaust on your car?
Do you need to alter your tuning?

shaggs · 14th November 2007, 02:54 PM

Hey guys.
My 036 was an experiment at first. As I said I have had "ol faithful" for years and apart from changing piston/rings has served me well.
There is a percentage of "opening up" the exhaust that you must limit yourself too. (From memory it may be that your muffler be no more than 80% larger than your cylinder exhaust...but will check).
She is louder, and sounds "beefier" next to a stocker but no difference with ear protection on.
They reccommend retuning after each mod. Simple to do and I pretty much retune after each clutch/filter change etc. But Some have been modded with unaltered carbs if the mod is not dramatic.
Some things to remember...
1. Watch which way you point the exhaust. (blowback, melted plastic/hands etc)
2. Dont protrude it too far that it hit the log before your dogs do.
3. Watch for burning bark.
4. This saw has no spark arrester in the pipe so watch it if you are in fire zones.
5. Angle it so that no dust/dirt falls in thru the muffler when not in use, as this is a direct line to your cylinder.
6. She cools down quicker and doesn't seem to run as hot.

I only used the 19mm0d/14mm id tube 'cuz thats what was in the garage at the time!!!

shaggs · 15th November 2007, 03:03 AM

Sorry Playford, I just realised I missed one of your questions. "How does it make a difference?"
Yes, its just like a sports exhaust on a car...less restriction, therefore more flow...more go. Manufacturers are bound to keep emissions low, sound low and sparks out. These all impede the natural flow of exhaust from the engine. The more restriction the more heat as well.

Ekka · 15th November 2007, 03:08 AM

Hmmm

Muffler mods seem a real specialty area. Yanks call them "pipes" and spend big on custom made ones for racing.

I heard that by AREA on a 2 stroke the muffler exit shouldn't exceed by more than 25% the surface area of the exhaust port.

What I dont understand and seems to make a lot of difference is the expansion chamber size.

Even with Rotax's v8 chainsaw you'll see on 4 strokes pipes go straight out to atmosphere yet on 2 strokes they have a chamber (muffler body thingo). Like what would happen if you just had a pipe going straight out of a 2 stroke also?

shaggs · 15th November 2007, 03:20 AM

VERY loud, and actually loose power as back pressure is required.
With engines that are manufactured to their near maximum horsepower, such as 2 stroke racing dirt bikes, they have a large expansion chamber that is "tuned". Very delicate stuff to modify or change. They aren't limited (at the time) to the emissions and noise debate required for on road vehicles etc.
For a chainsaw it would be impracticle to have a tuned pipe, although serious racing saw do have them.
I keep my mods "least change for most gain". Remembering these are all "working" saws where I still expect maximum reliability and functionality.
I always figured if the mod didn't work, just reweld up the pipe!!!!!! LOL

Ekka · 15th November 2007, 03:50 AM

So how do you tune a pipe?

Or, how do you engineer a tuned pipe? Like what is the criteria for making it perfect? Guess work?

treekiwi · 15th November 2007, 12:22 PM

Have been told that removing the spark arrester can help with more power, because of the carbon build up on the arrester, how much difference can this small mod make?

Ekka · 15th November 2007, 12:33 PM

A fair bit, especially on a 200T.

shaggs · 15th November 2007, 12:47 PM

The pipes I put on my saws are really just tube to increase air flow from the engine. The tuned pipes on 2 stroke motorbikes with expansion chambers I tries to understand once....ONCE. Very technical with flow and pressure guages required!
Treekiwi, alot of performance loss with an older saw can be attributed to carbon buildup in the muffler. Even just cleaning out alot of the built up carbon each year will keep it working nice.
It will also stop large chunks of carbon falling off and back into your cylinder when she's riding around in the back of the ute..

playfordtree · 15th November 2007, 07:28 PM

Howdy shaggs,

Your not wrong about trying to understand expansion chambers

, i've been told its all about getting the "pulse" of the exhaust flow in balance with the back pressure.

Also same sought of thing with "tuned length" extractors on a car, each "pulse" of exhaust gas from each cylinder has to be perfectly in tune with the "pulse" of the cylinder before and the "pulse" of the cylinder after.
Pretty complicated stuff and far too hard to try and understand on a hot Adealide afternoon.

Regarding your saw,

is the pipe just welded to the cover, or is it inserted inside muffler somewhat?
have you done anything to the muffler internally?
with the decrease in heat did you notice a reduction in fuel consumption?

Cheers mate

shaggs · 15th November 2007, 08:13 PM

G'day Playford,
I just took the outer muffler cover off the saw. Drilled at an angle with a step drill (although large normal drill will do). INSERTED pipe thru just a tad, but only welded on outside on a very LOW setting with a mig. Sprayed with high temp paint and haven't touched it for years.
Always take off muffler so no shavings end up in your cylinder. Its a good chance to clean all the carbon out too. I think I actually left the spark arrestor in this one as I use it to cut firewood (which is often in dead grass).
To be honest, I never really noticed any fuel reduction, mainly power and faster cooling.
Cheers

DBS · 21st November 2007, 04:56 PM

Quote:

Originally Posted by Ekka

A fair bit, especially on a 200T.

what was that mod we spoke of regarding the muffler packing and then some tuning would be required???

-Daryl

Therrin · 22nd November 2007, 07:17 PM

I actually just ordered a spark arrestor to put BACK on my 200T, since it didn't have one (used) when I got it.

But then I tend to work in foresty areas pretty frequently, and with all the fires in California lately I'd not like to be the one "playing with the box of matches". It doesn't take long to take a wire brush to it at the end of the day.

kevlar · 22nd November 2007, 07:53 PM

muffler mods are a great way to improve performance on a saw,but as was stated some fore thought is required,have seen people drill holes in the muffler and call it modded to me this is bs.(you would not drill holes in your truck muffler would you?)As for other items removal of the base gasket is a good start bumps up compression reseal cylinder with some sealant though!

30 thou off the bottom of both piston skirts and ten thou off the top off the piston now we have a fairly fast saw!

as far as porting you better know what you are doing!! My first attemt I stuffed a ring into the exhaust port and ruined a top end-Not good!

kevlar · 22nd November 2007, 07:55 PM

Quote:

Originally Posted by Therrin

I actually just ordered a spark arrestor to put BACK on my 200T, since it didn't have one (used) when I got it.

But then I tend to work in foresty areas pretty frequently, and with all the fires in California lately I'd not like to be the one "playing with the box of matches". It doesn't take long to take a wire brush to it at the end of the day.

I usually build my modded mufflers with a screen why take that chance right?
Although I have seen more sparks off of a bar and chain than I have ever seen from any saw muffler!

14th November 2007, 01:56 AM	#1 (permalink)
shaggs Afterburner is shakin' Join Date: May 2007 Location: sydney Posts: 459	Modded Saws Hi All Just thought I'd show a couple of pics of an old 036 stihl I did an exhaust mod on a few years ago. Its just a piece of 19mm tube MIG welded to the exhaust and painted with high temp paint. It really did/has made a difference and I haven't had any prob with it. It's not the prettiest but it does work and holds WOT longer. Anyone else modded any saws and noticed good gains or nil gains or problems? I have also done 019's, 039, 066 but not the newer 361's as som say they dont respond as well. Thanks EKKA for the help with the pic's. Cheers rsz_036mod1.jpg rsz_036mod2.jpg

14th November 2007, 02:26 AM	#2 (permalink)
Quintrex Afterburner is shakin' Join Date: Jun 2007 Location: Sydney Posts: 414	Re: Modded Saws How much extra noise?

14th November 2007, 02:52 AM	#3 (permalink)
Tree Machine Astronaut Join Date: Mar 2007 Location: Indianapolis Posts: 567	How much more? More.

14th November 2007, 04:24 AM	#4 (permalink)
playfordtree Afterburner is shakin' Join Date: Oct 2007 Location: Adelaide Australia Posts: 340	Re: Modded Saws I haven't had much to do with modding saws Shaggs. (Apart from ripping out those stupid spark arrestors.) How does the pipe make a difference? What does it do? Is it like putting a sports exhaust on your car? Do you need to alter your tuning? __________________ I Drink Therefore I am.

14th November 2007, 02:54 PM	#5 (permalink)
shaggs Afterburner is shakin' Join Date: May 2007 Location: sydney Posts: 459	Re: Modded Saws Hey guys. My 036 was an experiment at first. As I said I have had "ol faithful" for years and apart from changing piston/rings has served me well. There is a percentage of "opening up" the exhaust that you must limit yourself too. (From memory it may be that your muffler be no more than 80% larger than your cylinder exhaust...but will check). She is louder, and sounds "beefier" next to a stocker but no difference with ear protection on. They reccommend retuning after each mod. Simple to do and I pretty much retune after each clutch/filter change etc. But Some have been modded with unaltered carbs if the mod is not dramatic. Some things to remember... 1. Watch which way you point the exhaust. (blowback, melted plastic/hands etc) 2. Dont protrude it too far that it hit the log before your dogs do. 3. Watch for burning bark. 4. This saw has no spark arrester in the pipe so watch it if you are in fire zones. 5. Angle it so that no dust/dirt falls in thru the muffler when not in use, as this is a direct line to your cylinder. 6. She cools down quicker and doesn't seem to run as hot. I only used the 19mm0d/14mm id tube 'cuz thats what was in the garage at the time!!!

15th November 2007, 03:03 AM	#6 (permalink)
shaggs Afterburner is shakin' Join Date: May 2007 Location: sydney Posts: 459	Re: Modded Saws Sorry Playford, I just realised I missed one of your questions. "How does it make a difference?" Yes, its just like a sports exhaust on a car...less restriction, therefore more flow...more go. Manufacturers are bound to keep emissions low, sound low and sparks out. These all impede the natural flow of exhaust from the engine. The more restriction the more heat as well.

15th November 2007, 03:08 AM	#7 (permalink)
Ekka Eric Frei Administrator - Brisbane L5 (Dip) Hort Cert III Arb + some Join Date: Jan 2007 Location: Brisbane Posts: 5,673	Re: Modded Saws Hmmm Muffler mods seem a real specialty area. Yanks call them "pipes" and spend big on custom made ones for racing. I heard that by AREA on a 2 stroke the muffler exit shouldn't exceed by more than 25% the surface area of the exhaust port. What I dont understand and seems to make a lot of difference is the expansion chamber size. Even with Rotax's v8 chainsaw you'll see on 4 strokes pipes go straight out to atmosphere yet on 2 strokes they have a chamber (muffler body thingo). Like what would happen if you just had a pipe going straight out of a 2 stroke also? __________________ Remember to use the "search" function, if you have answers/questions post them so everyone can benefit. Free Tree and Green Industry Link Directory Qualified Brisbane Tree Lopping Brisbane Tree Care, Consultations and Arborist Reports Forum Sponsors

15th November 2007, 03:20 AM	#8 (permalink)
shaggs Afterburner is shakin' Join Date: May 2007 Location: sydney Posts: 459	Re: Modded Saws VERY loud, and actually loose power as back pressure is required. With engines that are manufactured to their near maximum horsepower, such as 2 stroke racing dirt bikes, they have a large expansion chamber that is "tuned". Very delicate stuff to modify or change. They aren't limited (at the time) to the emissions and noise debate required for on road vehicles etc. For a chainsaw it would be impracticle to have a tuned pipe, although serious racing saw do have them. I keep my mods "least change for most gain". Remembering these are all "working" saws where I still expect maximum reliability and functionality. I always figured if the mod didn't work, just reweld up the pipe!!!!!! LOL

15th November 2007, 03:50 AM	#9 (permalink)
Ekka Eric Frei Administrator - Brisbane L5 (Dip) Hort Cert III Arb + some Join Date: Jan 2007 Location: Brisbane Posts: 5,673	Re: Modded Saws So how do you tune a pipe? Or, how do you engineer a tuned pipe? Like what is the criteria for making it perfect? Guess work? __________________ Remember to use the "search" function, if you have answers/questions post them so everyone can benefit. Free Tree and Green Industry Link Directory Qualified Brisbane Tree Lopping Brisbane Tree Care, Consultations and Arborist Reports Forum Sponsors

15th November 2007, 12:22 PM	#10 (permalink)
treekiwi Cruisin' Join Date: Nov 2007 Location: New Zealand Posts: 85	Re: Modded Saws Have been told that removing the spark arrester can help with more power, because of the carbon build up on the arrester, how much difference can this small mod make?

15th November 2007, 12:33 PM	#11 (permalink)
Ekka Eric Frei Administrator - Brisbane L5 (Dip) Hort Cert III Arb + some Join Date: Jan 2007 Location: Brisbane Posts: 5,673	Re: Modded Saws A fair bit, especially on a 200T. __________________ Remember to use the "search" function, if you have answers/questions post them so everyone can benefit. Free Tree and Green Industry Link Directory Qualified Brisbane Tree Lopping Brisbane Tree Care, Consultations and Arborist Reports Forum Sponsors

15th November 2007, 12:47 PM	#12 (permalink)
shaggs Afterburner is shakin' Join Date: May 2007 Location: sydney Posts: 459	Re: Modded Saws The pipes I put on my saws are really just tube to increase air flow from the engine. The tuned pipes on 2 stroke motorbikes with expansion chambers I tries to understand once....ONCE. Very technical with flow and pressure guages required! Treekiwi, alot of performance loss with an older saw can be attributed to carbon buildup in the muffler. Even just cleaning out alot of the built up carbon each year will keep it working nice. It will also stop large chunks of carbon falling off and back into your cylinder when she's riding around in the back of the ute..

15th November 2007, 07:28 PM	#13 (permalink)
playfordtree Afterburner is shakin' Join Date: Oct 2007 Location: Adelaide Australia Posts: 340	Re: Modded Saws Howdy shaggs, Your not wrong about trying to understand expansion chambers, i've been told its all about getting the "pulse" of the exhaust flow in balance with the back pressure. Also same sought of thing with "tuned length" extractors on a car, each "pulse" of exhaust gas from each cylinder has to be perfectly in tune with the "pulse" of the cylinder before and the "pulse" of the cylinder after. Pretty complicated stuff and far too hard to try and understand on a hot Adealide afternoon. Regarding your saw, is the pipe just welded to the cover, or is it inserted inside muffler somewhat? have you done anything to the muffler internally? with the decrease in heat did you notice a reduction in fuel consumption? Cheers mate __________________ I Drink Therefore I am.

15th November 2007, 08:13 PM	#14 (permalink)
shaggs Afterburner is shakin' Join Date: May 2007 Location: sydney Posts: 459	Re: Modded Saws G'day Playford, I just took the outer muffler cover off the saw. Drilled at an angle with a step drill (although large normal drill will do). INSERTED pipe thru just a tad, but only welded on outside on a very LOW setting with a mig. Sprayed with high temp paint and haven't touched it for years. Always take off muffler so no shavings end up in your cylinder. Its a good chance to clean all the carbon out too. I think I actually left the spark arrestor in this one as I use it to cut firewood (which is often in dead grass). To be honest, I never really noticed any fuel reduction, mainly power and faster cooling. Cheers

22nd November 2007, 07:17 PM	#16 (permalink)
Therrin The Tree World Bandit Join Date: Oct 2007 Location: Lancaster, Ca Posts: 1,113	Re: Modded Saws I actually just ordered a spark arrestor to put BACK on my 200T, since it didn't have one (used) when I got it. But then I tend to work in foresty areas pretty frequently, and with all the fires in California lately I'd not like to be the one "playing with the box of matches". It doesn't take long to take a wire brush to it at the end of the day. __________________ Ken Fessia I.T.S.A. Tree Service (661) 916-4703

22nd November 2007, 07:53 PM	#17 (permalink)
kevlar Gettin' motoring Join Date: Nov 2007 Location: British Columbia Posts: 47	Re: Modded Saws muffler mods are a great way to improve performance on a saw,but as was stated some fore thought is required,have seen people drill holes in the muffler and call it modded to me this is bs.(you would not drill holes in your truck muffler would you?)As for other items removal of the base gasket is a good start bumps up compression reseal cylinder with some sealant though! 30 thou off the bottom of both piston skirts and ten thou off the top off the piston now we have a fairly fast saw! as far as porting you better know what you are doing!! My first attemt I stuffed a ring into the exhaust port and ruined a top end-Not good! __________________ Got Wood!! olympyk 264 deluxe,999.jonsered 66e.huskvarna 394. stihl 026pro,036pro,038 mag,045,046,460,056mag,066,075.homelite super xl and xl12. pioneer 600a,maculloch d36and pro mac1000.whew! What out for the boy he's crazy!!