Muffler Mod, how big is too big

Treestuff
Wesspur
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Can cut and paste to word and save as a .doc, but none of the math or functionality of and .xls file would be transfered.

.doc seams to keep the rows and columbs, .txt did not, .html got wacky too.
 
hello everybody.


Fantastic posts for me. congratulations for the a lot of useful information I have found in your web and due to it I have bought my first chainsaw(Husqvarna 346xp) .Thank you very much.

I am sorry because don't know English very well.:bang:
 
timberwolf said:
There is more I want to do with this, but it all takes time.

How does a tube stack up to the round hole of the same diamiter?
Muffler temp, head temp and fuel consumption?

Also have two modified 026s, I would like to repeat the test with those saws to see if there are any differences? One saw is ported low for torque, the other ported very high realy designed to run on alky and pipe.
Click to expand...

Hey TW theres a thread going asking about tubes rather than holes, Did you ever do any testing on the shape of the outlet other than the zero backpressure muffler?

http://www.arboristsite.com/showthread.php?t=96073

Im thinking the pipes would need to be too long to be of any benifit.
 
Timberwolf

thanks for all the reserch on the 026 i looked at your charts and decided to inlarge the stock hole to 31/64 altho most people just add two smaller holes above and below. The saw may be a little faster (no timed cut) ( cutting 10 dry pinoak limb in a vice) but mutch more tork than before mod, i could not push saw much(20'bar) now i can stand on it with no stall.
 
Timberwolf

You may have enjoyed all that port testing on 026 but I loved all the fact that you took time to post it. Again I really appreciate it.
Ok I have read about problems with h adjustment on 026 (my muffle had no baffles just a very small exhaust hole) after mod i had to adjust L screw more than H. I thought something was wrong so i screw L in until saw died the backed out until it would run and then screwed H in until it would not rev and backed out until it would then i set wot. this thing will scream leaned out when i try to go just a little further to richen it dosn't sound rite alltho rpm come down then if i keep holding wot no matter how rich i get it i cant drown it out and saw will eventually take gas and begin over reving.
is this two stroking need help
 
timberwolf said:
Had some time and gave the test a run through with the modified saw, I used the same bar and chain, though the chain was not realy enough for the saw and I was pushing too much to do the cut times and saw justice.

This saw is not a high reving saw, exhaust port duration is acctually a little lower than stock. Built for torque, that it has, will pull 3/8 8 pin on muffler. Though in this test I was using 8 pin .325 for both saws.

Here are the numbers, again experienced the same need to richen the LS on the first couple openings and acctually lean the HS. This time the gains did not level off as much as with the stock saw.

Again up arround 180-190% of the port area the idle started getting touchy and it was nessicary to crank up a few hundred RPM.
Click to expand...

On one data sheet (post 30), you show stock WOT RPM's being greater than mod WOT RPM's, yet cut times go down. Why is this? (Rows 16 and 17)
 
How do these rules change on larger saws (70-90cc)? How does the ratio of cylinder port area to muffler port area change as the cc's of the saw increases?
 
stihlhere said:
You may have enjoyed all that port testing on 026 but I loved all the fact that you took time to post it. Again I really appreciate it.
Ok I have read about problems with h adjustment on 026 (my muffle had no baffles just a very small exhaust hole) after mod i had to adjust L screw more than H. I thought something was wrong so i screw L in until saw died the backed out until it would run and then screwed H in until it would not rev and backed out until it would then i set wot. this thing will scream leaned out when i try to go just a little further to richen it dosn't sound rite alltho rpm come down then if i keep holding wot no matter how rich i get it i cant drown it out and saw will eventually take gas and begin over reving.
is this two stroking need help
Click to expand...

do a search on tuning a saw, this does not sound right.
 
i tuned my own saws forever and never had this problem.# but just to let you know i read all those before i posted.# I thought i had heard something about some models wont richen up enough.# wondering about carb mod or replacement.# I have a few ms290 carbs dont know if they would# be any better.# That being said i removed a 18" oak today ant the 026 just riped compared to before It also cranked easier.
 
attachment.php
attachment.php
So do I have to cut my tubes off or can I leave them on?I really want to leave them on but I want the most power and torque I can get.
attachment.php
These are on my Snellerized 359.
 

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