# Stihl 260 muffler mod data, temp, sound level and preformance



## timberwolf (Oct 26, 2002)

Here is the data I measured during a muffler modification on my 260.

Saw is was new 3-4 tanks of gas, sharp .325 Stihl RS chain on a 16" bar.

Tempratures were measured with a digital lazer spot infared sensor. measuements were taken from the hottest area on the front of the muffler cover, and the hottest exposed area of the head which seemed to be just below the cooling fins on the bar side. Outside air temperature 5 degrees C.

Sound levels were measured using a calibrated digital sound meter, peak measurments were taken at 10 feet directly in front of the saw with both the saw and meter 3' above the ground (open field).

Cut times were 3 cut averages measured by stop watch on a 12" dry spruce.


The muffler modification entailed 5 steps.

1 stock
2 stock muffler redrill existing outlet to 7/16 and add one 7/16 hole
3 add one more 7/16 hole
4 join 3 holes and square opening to 7/16 x 1.5 inch plus file back and open deflector angle.
5 match exaust port to muffler

The test consisted of the folowing steps

1 measure temp with saw cold roughly 7 degrees C
2 start and idle saw for 2 min monitor temp until stable
3 measure idle sound level
4 cycle saw to full RPM 5 times and record max sound and rpm
5 cycle saw between idle and full rpm for 1 min and measure temp
6 cut 3 disks and measure temp
7 allow saw to cool befor next test

AND HERE IS WHAT I FOUND
-----------------------------------

Stock muffler opening 0.11 sqr inches
---------------------------

RPM 13450 
Idle sound level 80.2 db 
Max sound level 97.1 db
Idle temp muffler 64 C
Idle temp head 60 C
Cycle test temp muffler 119C
Cycle test temp head 68C
3 cut test temp muffler 183C
3 cut test temp head 105C
3 cut test time 8.5 sec


Muffler with two 7/16 openings total 0. 30 sqr inch
---------------------------------------

RPM 13650 +1.5% 
Idle sound level 84.9 db +5.9% 
Max sound level 99.5 db +2.8%
Idle temp muffler 62 C -3.2%
Idle temp head 58 C -3.4%
Cycle test temp muffler 89C -33.7%
Cycle test temp head 62C -9.7%
3 cut test temp muffler 164C -11.6%
3 cut test temp head 96C -9.4%
3 cut test time 8.0 sec -6.3%

Muffler with three 7/16 openings total 0.45 sqr inches
-----------------------------------------

RPM 13750 +2.2%
Idle sound level 87.1 db +8.7%
Max sound level 101.8 db +4.8%
Idle temp muffler 56 C -14.3%
Idle temp head 55 C -16.4%
Cycle test temp muffler 88C -35.2%
Cycle test temp head 62C -9.7%
3 cut test temp muffler 147C -24.5%
3 cut test temp head 105C -12.9%
3 cut test time 7.6 sec -11.8%

Muffler with one 7/16 x 1.5 inch opening total 0.66 sqr inches
--------------------------------------------------

RPM 14000* +4.1%
Idle sound level 89.9 db +12.1%
Max sound level  103.0 db +6.1%
Idle temp muffler 54 C -18.6%
Idle temp head 52 C -15.4%
Cycle test temp muffler 82C -45.2% 
Cycle test temp head 61C -11.5%
3 cut test temp muffler 143C -28.0%
3 cut test temp head 85C -23.6%
3 cut test time 6.9 sec -24.6%

* mixture richer by a hair RPM = 14100 before adjustment

Exaust port matched and smoothed
---------------------------------------------

RPM 14050 +4.4%
Idle sound level 89.9 db +12.1% NC
Max sound level 103.0 db +6.1% NC
Idle temp muffler 54 C -18.6% NC
Idle temp head 51 C -17.6%
Cycle test temp muffler 82C -45.2% NC 
Cycle test temp head 61C -11.5% NC
3 cut test temp muffler 143C -28.0% NC
3 cut test temp head 83C -26.5%
3 cut test time 6.7 sec -26.8%


Other Notes

My cutting tequnique may have improved over the tests, however I was cutting disks off towards the larger end of the log during the last few tests, so it probably equals out.

The air temprature was cool for the tests, the engine tempratue factors may well be more pronounced if the same tests were done during hot weather. 

Even though the sound level data shows an increase of 12% idle and 6% maximum the real change in much greated due to the logarithimic nature of the db scale, the precieved change of a 10 db increase as in the saw idle measurments would be that the sound level has doubled.

Allthough the mixture seemed to be good at 14000 rpm I richened it to achieve 13800 when I was finished.

gains don't seem to be falling off too fast so I will likely open up the muffler a wee bit more in the future.

Data tables don't post well, I think I'l make it a text file and attach it next time.

Wife didn't think much of me spending most of the day making the chain saw louder! Just wait til I finish the 066. lol

Timberwolf


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## treeclimber165 (Oct 26, 2002)

*WOW!*

Thanks for putting this together. This the type of info most typical saw owners need to see. I appreciate how you strived to make the info as accurate as possible. Even with any standard of variance, your results show ABSOLUTE proof that muffler mods reduce head and muffler temps and allow the saw to perform better with less resistance. Heck, I gotta bookmark this thread! 


I rated this thread a '5'. When it gets enough votes, the rating will show up.


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## chainsawworld (Oct 26, 2002)

timberwolf,
do you or did you ever work for me? sounds like the crazy sick stuff we do here. marty


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## Crofter (Oct 26, 2002)

*--Faster AND Cooler--*

This is what we have been hearing about muffler modifications on the newer restricted saws. 25%or so faster and seem to run cooler. It is nice to see actual measured cylinder an muffler temperatures to support it. So what if you do have to buy your wife a pair of ear muffs too!

Crofter


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## tundraotto (Oct 26, 2002)

well done Timberwolf!!! Well performed test. I am glad to see some empirical data about the temperatures especially. Your time spent is well appreciated!! Just shows how we have been screwed by the EPA....

PS. could you do a test with your Raytek regarding fuel mix, ie. 32:1 head temp vs. 50:1 head temp??? That would be another interesting one.


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## rahtreelimbs (Oct 26, 2002)

*Timberwolf!!!*

Thanks for taking the time to do these tests. This is as Tim said concrete proof. The mufflers that I modified made the saws feel stronger as I never had any solid proof.


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## timberwolf (Oct 26, 2002)

Yes that would be interesting to check mix VS head temp.
I should have mentioned in my original post that the mix was 40:1 with Stihl oil for the muffler tests, I guess it could make a differnce.


It is a bit dark out now, and with that modified muffler I'd just get busted by the noise police aka "WIFE"

I will give it a try tomorow

Timberwolf


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## bwalker (Oct 26, 2002)

Good job. Its good to see someone finnaly prove and doccument what many have thought for so long=Epa mufflers are cooking our saws and killing power. As afar as the mixture thing goes. the only thing you will have to watch out for is keeping the adjustments equal. IE more oil will lean it out slightly so the mixture screws must be a bit richer, in practice this amount is very slight, but it could still make a differance.


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## stihltech (Oct 26, 2002)

*excellent*

Nice job. Real world testing.


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## Tom Dunlap (Oct 27, 2002)

On Thursday I called my brother in Dallas and asked him to send me his sound meter. As i start to tweak mufflers I want to collect sound ratings. I don't have a temp meter though. I plan on collecting the dB changes and cutting time changes. The nursery has a pile of old 6x6 timbers for me to cut up. They should be pretty uniform.

Thanks for taking the time to collect and post this valuable information.

Tom


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## Acer (Oct 27, 2002)

This is really good work, and takes the idea of exhaust mods beyond anecdote. 

I noticed your RPM increased in line with opening area, so anyone attempting these mods ought to retune their saw to avoid engine damage through over-revving (max. engine speed on an 026 is quoted as 14,000 rpm in the manual).

Just one thing: I think the perceived noise increase is more than you think. You're right about the dB scale being logarithmic, but a 3dB increase represents a doubling in sound pressure level.


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## Kneejerk Bombas (Oct 27, 2002)

The test is great.
One question I have is about the RPMs and cut speed. Shouldn't you have adjusted the carb to the same factory reccomended setting each time? 
I say this because just leaning out the carb to increase RPMs would decrease cut times, to some extent, wouldn't it?


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## camel (Oct 27, 2002)

*That is why i love this site...*

Verry Good Job !!!!


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## chainsawworld (Oct 27, 2002)

timberwolf,
i'm glad you proformed your tests and got a great welcome. i recall posting some information close to what you did and it did not go over as well. i heard things like a hand held instrument (tach or thermometer) can not hold a true reading. lots of people enjoyed what i posted but a few fought my results. i also supplied timed cutting results. thank you; marty


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## tundraotto (Oct 27, 2002)

when was this marty? I belive by the description that timberwolf used a Raytek infrared thermometer that is the industry standard and record the temp with a .1 degree accuracy - approx between 50 -1300 degrees - is that what you used? tach is great to use, but where your test conducted in specified conditions like these were? ie. same saw, same beginning temp, same log, same sawyer, same chain, same day, etc.??? please post a link.


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## timberwolf (Oct 27, 2002)

> One question I have is about the RPMs and cut speed. Shouldn't you have adjusted the carb to the same factory reccomended setting each time?



I can see your point but,

I intentionaly avoided adjusting the mixture, it would have thrown another wild card in, I only adjusted it when the saw did not break between 2 and 4 cycle at full unloaded throtle.

Now wether the saw was increasing RPM through leaning of the mixture due to increased flow and improved scavenging or wether it was less resistance to exaust flow (another question). I would think most likely a combination of factors.

Timberwolf


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## timberwolf (Oct 27, 2002)

> Just one thing: I think the perceived noise increase is more than you think. You're right about the dB scale being logarithmic, but a 3dB increase represents a doubling in sound pressure level.




Actualy I had to double check this in a text book befor my original post, 3db is a doubling is sound preasure level, but our ears don't follow a liniar responce to the SPL. according to The text I have concerning sound systems a 10 db gain is what the average person precieves to be a doubling of apparent sound level.

If a 3 db gain was precieved as twice as loud then the 9-10 db increase would be precieved as 8 times as loud. The saw was louder but not that much louder.


This sure builds a case for good hearing protection, proper ear muffs give a typical db atenuation of -25db to -30db. if the saw is 103 db at 10 feet it would be more like 110 to 115 for the opperator. With established so called safe sound levels being around 85db ear muffs would provide only marginal protection. This is likely part of the rational to restrict mufflers to ensure that standard hearing protection brings sound levels within ocupational health and safety guidelines.

Timberwolf


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## chainsawworld (Oct 27, 2002)

i'll go back through the threads. it was with a 372xp. the muffler was walkerized,digtial tach and laser thermo. the cants were 8x8, same day, same carb settings and on and on!!!!!! marty


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## tundraotto (Oct 28, 2002)

well....what did you find Marty?


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## Acer (Oct 28, 2002)

> _Originally posted by timberwolf _
> *Actualy I had to double check this in a text book befor my original post, 3db is a doubling is sound preasure level, but our ears don't follow a liniar responce to the SPL. according to The text I have concerning sound systems a 10 db gain is what the average person precieves to be a doubling of apparent sound level.
> 
> *



I learn something every day. In a previous job, I used to take rough sound surveys in factories, just to see if a more in depth survey was needed. We were more interested in sound pressure level, as this does the damage. Then, the acceptable dose was the equivalent of 90dB over an 8 hour period (it has dropped to 85 dB now, I believe)- any higher would result in hearing damage. So, an operator running a saw with no hearing protection and experiencing 114dB, say, would receive their dose in just under 2 minutes!!


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## sritzau (Oct 28, 2002)

Are there earlier versions of the 026 that did not have to meet the same EPA regulations as the current ones? If so, it would be interesting to see what they had for open areas in their mufflers and try to figure out how the folks at Stihl settled on that value.

Steve


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## bwalker (Oct 28, 2002)

This is just a swag, but I would guess that pre EPA saws will benifit some from muffler mods also as the stock mufflers are restrictive for ANSI noise standards.


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## 046 (Jun 15, 2005)

muffler mod coming up on my 026


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## chowdozer (Jun 15, 2005)

Good information!

I'm guessing you used a Raytec or similiar non-contact infrared thermometer. A word of caution when using these type of instruments: It is very difficult to get an accurate temperature measurement unless you are able to obtain an emissivity value of the material you are pointing at and even then bare aluminum is a no-no. In layman's terms, the measurement of the muffler is probably within 10% of actual. The cylinder head temp is probably way off. Reason being that flat black is a good emitter, ie heat radiator with an emissivity of 0.90 or greater. Unpainted aluminum is a very poor emitter, (emissivity of <0.20) and in fact aluminum sanded with 100 grit sandpaper is a very good infrared mirror causing you to measure heat reflected from something else. (Just for info, emissivity + relectivity = 1) where emissivity is the ability to radiate heat and reflectivity is the ability to reflect heat. Think "space blanket" or one of those parabolic reflectors on an electrical heater. I'm reasonably certain that if you were to paint a cylinder with VHT Flameproof coating and use an emissivity # of 0.92 in your Raytec you would get a different number. The VHT would also help the saw to run cooler. Why engine manufaturer's don't paint them black, I have no idea. Woodstove manufacturer's know about flat black paint.

I do believe that your temperature differentials are valid.

Greg
(thermal non-contact measurements are my job)


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## DanMan1 (Jun 15, 2005)

chowdozer said:


> Good information!
> 
> I'm guessing you used a Raytec or similiar non-contact infrared thermometer. A word of caution when using these type of instruments: It is very difficult to get an accurate temperature measurement unless you are able to obtain an emissivity value of the material you are pointing at and even then bare aluminum is a no-no. In layman's terms, the measurement of the muffler is probably within 10% of actual. The cylinder head temp is probably way off. Reason being that flat black is a good emitter, ie heat radiator with an emissivity of 0.90 or greater. Unpainted aluminum is a very poor emitter, (emissivity of <0.20) and in fact aluminum sanded with 100 grit sandpaper is a very good infrared mirror causing you to measure heat reflected from something else. (Just for info, emissivity + relectivity = 1) where emissivity is the ability to radiate heat and reflectivity is the ability to reflect heat. Think "space blanket" or one of those parabolic reflectors on an electrical heater. I'm reasonably certain that if you were to paint a cylinder with VHT Flameproof coating and use an emissivity # of 0.92 in your Raytec you would get a different number. The VHT would also help the saw to run cooler. Why engine manufaturer's don't paint them black, I have no idea. Woodstove manufacturer's know about flat black paint.
> 
> ...



Greg, My experience with infrared thero, is in total alignment with what you posted. On metals the reading is severly distorted by suface impuraties. Just a speck of paint or rust, or a small rough or smooth area throws off the reading. Different stainless steel formulas give totaly different results, even when you look up the emisivity from a chart and dial in the meter. I DO think they don't paint the heads because convection and conduction accounts for more cooling on engines than radiation. And any paint applied reduces conduction heat transfer. Painted woodstoves favor radiation because they want to heat object across rooms and can't rely on convection provided by a flywheel fan.


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## bwalker (Jun 15, 2005)

Using a infared device to measure the heat of a motor is a scientific circle jerk.
I had a HVAC guy out at my place this winter and he basicly confirmed what I thought all along about the devices lack of accuracy.


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## Al Smith (Jun 15, 2005)

bwalker said:


> Using a infared device to measure the heat of a motor is a scientific circle jerk.
> I had a HVAC guy out at my place this winter and he basicly confirmed what I thought all along about the devices lack of accuracy.


Well Ben,are you a thermal expert?Most infrared measuring devices take the measurements with ambient,or background temperature as a reference.If your theory holds true,then American as well as world wide industry has spend billions of dollars on a fluke.If ,however,the calibration of these measuring devices are inaccurate,then so would be the measurements.I will admit that you can't compare the several hundred dollar device the furnace man had to the $40,000 one we have where I work,which I will say is very accurate.


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## bwalker (Jun 15, 2005)

Al, dont be banal. Of course I am talking about the units bought at home depot and such and not the 40k units you have at work.
When I visited a test cell dyno at one of the large American auto companies a few years back I sure as heck didnt see any engineers taking readings with a infared device. Rather every thing was measured via digital temp gauges and thermcouples.


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## chowdozer (Jun 15, 2005)

to Al. I have 8 thermal imagers at work and two portable IR spectrometers. The measly $60-80K per imager isn't the costly part, it's the $300-400K for the lenses. That's per imager. Raytec's are notoriously inaccurate, but with careful preparation, they can do in a pinch.


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## Al Smith (Jun 15, 2005)

How then,may I ask,do they take measurements in the production of steel?


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## chowdozer (Jun 15, 2005)

Ben, sometimes a test engineer can't wire up thermocouples to the test object. Something about strapping loose wires on a supersonic jet engine that's going to roll out at 30K feet in a 7G turn. And sometimes, it might be a non-cooperative target.


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## chowdozer (Jun 15, 2005)

I need to clarify one of my previous posts. Anyone can take a top notch piece of equipment and produce results, often times undesirable results. Few people can take a less than top notch piece of equipment and produce good results. Nothing against Raytec, they are decent if the operator knows what he's doing. If the operator doesn't understand what he's doing, a $100K piece of equipment won't make his results any better. It's about preparation and understanding.


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## Al Smith (Jun 15, 2005)

I will agree that high end thermocouple devices,properly calibrated ,are far more accurate,but the use of thermal imaging devices has saved industry tons and tons of money by being able to detect potential problems with machinery breakdowns,faulty electrical devices and the like.On the opposite end of the light spectrum ,the ultraviolet devices have became well accepted as a means for ignition detection,etc.This posses a bit of a puzzle.All of our dyno cells at work,have state of the art temperature measuring devices,several for comparison,tied through a goobly gook of computers,monitoring devices etc etc.How,may I ask,would one take the temperature of an exhaust valve,if not for a thermal imager.


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## DanMan1 (Jun 16, 2005)

Al, apples and oranges.

Yes temperature measurement based on light energy measurement can be accurate and repeatable in a controlled environment and on known pure (that's the important part) materials. But come on, you have to admit thats not what you have with a used chainsaw muffler, is it? We all know that even after a minute of running a muffler develops areas with discoloration. Even a slight bluing of metal changes the emisivity. Then spots of missing paint, rust etc... So you are looking at a non pure material. How can you get repeatable accurate results from a handheld IR gun. You can't. You can get good ballpark results, but that's it.


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## chowdozer (Jun 16, 2005)

Several things to mention here Dan. 

It is wrong to call infrared energy light energy. It is an electromagnetic wave, just as radar or sound are. The wavelength of the typical IR bands, 3-5 um and in the case we're talking, 8-12 um, are much higher than light. Your eye only "sees" to the high .7 um, low .8 um. 

The higher the temperature, the less difference the coating makes. This is one of the reasons why a cavity blackbody is an optimum calibration source. (That and the elimination of reflections.)

Areas of discoloration aren't very important on a part under test - to some degree. One of the reasons I use VHT flameproof paint, is that it bakes into the metal somewhere around 300 C. It might look like crap, but it does perform well. When you paint a part, it's ok to slightly see the metal underneath. If you have too much coating, it may be insulating the part.

If you were going to perform a lower temp test, the best paint is Krylon ultra flat black. This is a high carbon paint and very emissive, E= 0.95 Trouble is, it doesn't stick to well either and flakes off at higher temperatures.

I agree that you can't get good results with Raytecs, or any other devices of that nature. The only instance I know of that they are used with some degree of accuracy is race car tires. But then, I don't think the E of the rubber varies much either.


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## DanMan1 (Jun 16, 2005)

chowdozer said:


> Several things to mention here Dan.
> 
> It is wrong to call infrared energy light energy. It is an electromagnetic wave, just as radar or sound are. The wavelength of the typical IR bands, 3-5 um and in the case we're talking, 8-12 um, are much higher than light. Your eye only "sees" to the high .7 um, low .8 um.
> 
> ...



Chowdozer, Nice mix of fact and fiction.

"It is wrong to call infrared energy light energy"

Sorry, you are wrong, plain and simple.
Just because it's not visible to human eyes doesn't mean it's not light. 
I'm sure like me you must have learned that in your first years at college.
To passify you I included a cople of random definitions I just grabed from the net below.

1)A band of the electromagnetic spectrum between the visible and the microwave.
2)Light of wavelength longer than the reddest part of the visible spectrum
3)Light waves just outside the visible spectrum; that is, waves slightly longer than those visible to the human eye. Infrared light is sometimes filtered out to reduce heat on film or slides. Also see Infrared control.

"It is an electromagnetic wave, just as radar or sound are"

Here is where I stopped reading your post. Sorry but on Earth, 'sound' is the result of physical movent of a solid, liquid or gas such as air, NOT an electromagnetic wave.


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## chowdozer (Jun 16, 2005)

> Sorry, you are wrong, plain and simple.
> Just because it's not visible to human eyes doesn't mean it's not light.
> I'm sure like me you must have learned that in your first years at college.
> To passify you I included a cople of random definitions I just grabed from the net below.
> ...



That’s a riot. I punched “light definition” into Google and took the third site. I took the third site because the first site said something about "web definitions of light". The second site was called “definition of the speed of light” or some such. So I took the third hit because it said "light ( līt ) n. Physics". That looked good. I read the first definition, here it is:

Electromagnetic radiation that has a wavelength in the range from about 4,000 (violet) to about 7,700 (red) angstroms and may be perceived by the normal unaided human eye.




> Sorry but on Earth, 'sound' is the result of physical movent of a solid, liquid or gas such as air, NOT an electromagnetic wave.



Yep, I brainfarted and I’m willing to admit it.  

Since we’re going to nitpick Dan, I want to know where you got this fiction?

“…can be accurate and repeatable in a controlled environment and on known pure (that's the important part) materials.” 

Why does it have to be “pure”? Exactly what is “pure”? The best measurement you can make is on a sooty part. It’s carbon and if it sticks, it’s the best material to get an IR measurement from. Period



> Nice mix of fact and fiction.



Ditto to you, Dan!
 
ps, use the spell check


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## BigUglySquirrel (Jun 17, 2005)

*little carried away....*

Hey fellas, I think it's great that you guys are so into the nuances of your respective technical fields. Is it possible to stop arguing with each other and try to come up with a variable for the equipment this fella is using? He's gone through all of the trouble of collecting data and establishing baselines and conducting tests to as strict a standard as he can. Obviously he's not using state of the art equipment in a controlled testing environment designed specifically for the application. ($40k thermocouples? I see them too...what's the chances one of us is going to obtain one and THEN use it properly at home?? When you get down to .001 of a degree, you'd better be able to control the ambient air temp down to that accuracy or your tests are crap anyway.) He's not using toys out of the Crackerjack box either. His testing methods are unbiased and consistent. So I pose this challenge to you, gentlemen: Can you put your heads together long enough to define a degree of accuracy? 5%? 15%? I know it's hard to set aside ingrained technical learning, but try to keep in mind...this is NOT a definitive thesis on the matter at hand. It IS a very well conducted test for the purpose of "heads-up" comparison. Make a few assumptions based on well conducted home testing.


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## chowdozer (Jun 17, 2005)

Can't argue with you there Chris. Timberwolf, my suggestions for the best measurements in the future are as follows:

Give the cylinder a light fogging of VHT flameproof black paint. Degrease first. Ideally a sandblast would be nice but we all have our dreams. Scuff up the muff removing all the paint you can. Fog it with the VHT also. Perform your test as you have outlined. If your intsrument has an emissivity setting indicated by a capital Greek E, set it to 0.92

All told though Timber, I think your delta temps, or differences (on the head and on the muff. I don't believe comparing the head temp to the muff temp would be accurate), are as accurate as your equipment can be. I would call your test a success for the answers you were after.


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## timberwolf (Jun 17, 2005)

Have not posted in a while, but this draws me out.

Given the objective is not to find the exact temprature, but to find the temprature change between each step much of the error canclels it self out.

When I did this test I found a spot on the head and one on the muffler that were giving the consistantly highest readings.

Since then I have looked at saws and pipes with a 20k thermal imaging camera, cool images, but they wouldn't shead one bit of additional light on the temprature change between 2 tests, as interpreting the color display is very subjective. However it was very interesting to see the hot spots where there is poor air cooling, where the xfer ports cool the jug, and where the exaust heats it. Might also be useful for pipe tuning.

I agree thermal couples would be better because they can be fixed in one location, can give constant output (heat curve), are not as affected by reflectivity but do have thermal lag that might need to be taken into account for.


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## whatsnext (Jun 17, 2005)

BigUglySquirrel said:


> Hey fellas, I think it's great that you guys are so into the nuances of your respective technical fields. Is it possible to stop arguing with each other. So I pose this challenge to you, gentlemen: Can you put your heads together long enough to define a degree of accuracy? 5%? 15%? I know it's hard to set aside ingrained technical learning, but try to keep in mind...this is NOT a definitive thesis on the matter at hand.




You must be new here.


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## tony marks (Jun 17, 2005)

good work timberwolf. u went to a lotto trouble to get useful info. we appreciate u publishing it.


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## Lobo (Jun 17, 2005)

Timberwolf, I echo what Tony has posted.

Most of us I guess realized off the bat that your testing was not perfect and it was to be used as a guideline and indicator primarily, more precise tooling would change the numbers slightly but the patterns would remain fairly consistent I am convinced.

Thanks again for all the work.


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## DanMan1 (Jun 17, 2005)

tundraotto said:


> when was this marty? I belive by the description that timberwolf used a Raytek infrared thermometer that is the industry standard and record the temp with a .1 degree accuracy - approx between 50 -1300 degrees - is that what you used? tach is great to use, but where your test conducted in specified conditions like these were? ie. same saw, same beginning temp, same log, same sawyer, same chain, same day, etc.??? please post a link.



Timberwolf,

This was the post that really sparked my initial response. Then someone had to tell me what I wrote was wrong, and then we are off to the races.

Assuming you put the beam on the same area of the components each time, you should feel comfortable stating that your relative ( not absolute) meaurements are good within a couple of degrees. As long as you don't state things like ".1 degree accuracy", you can't get any guff from people.


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## BigUglySquirrel (Jun 17, 2005)

Yeah...still pretty new to the site. Don't have a whole lot of time to sit on the computer...but this site is worth the time I squeeze in. Didn't mean to ruffle any feathers...it just seemed to be a a waste of obvious experience and expertise to quibble over things that mean little to nothing to most people. I'm not dogging anyone. I'm actually QUITE impressed with the amount of VERY informed and VERY well read contributors. It just kinda upset me to see guys get so caught up in technical comparisons that it kinda stole Timberman's thunder on a really good "homebrew" comparison. Sorry for any smashed toes....rock on!


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## ErrolC (Jun 18, 2005)

I have to add my 2c worth ...I just love this site...better than any of the drama my family watch on the idiot box..I love it..good effort & results timberwolf...all in the quest for knowledge..no one knows it all...some might think so.

Q: Few people are capable of expressing with equanimity opinions which differ from the prejudices of their social environment. Most people are even incapable of forming such opinions... Albert Einstein

Q:Only two things are infinite, the universe and human stupidity, and I'm not sure about the former...Albert Einstein

Q: Imagination is more important than knowledge... Albert Einstein


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## Al Smith (Jun 18, 2005)

Oh,what the heck,it's all good .As my grandaddy used to say"there is more than one way to skin a cat".


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## klickitatsacket (Jun 18, 2005)

Timberwolf  Thanks for the work you did and for posting it. When I first found it, I even printed out your results. I have a copy of them in my note books.This post is also why I do not post a lot of my testing data. Pi$$ on lazy nit pickers who do NOTHING but read or who have never tried to learn on their own with out the use of some one else's money. You could easily spend a half million dollars to prove exactly what you already proved. Muffler modification reduces heat and unrestricts flow. When it comes right down to it that's all you really need. If you really wanted to get picky just run the same tests 5 times each and take averages. The chances of NASA coming up with better data that is relatively meaningful would be about the same as congress doing something relatively meaningful.


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## cbfarmall (Jun 30, 2005)

Al Smith said:


> How then,may I ask,do they take measurements in the production of steel?




Hey, something I can answer. We use disposable thermocouples mounted on the end of a cardboard sleeve. In a basic oxygen furnace, the system is referred to as a sublance. The sleeve is meant to protect the sublance pole which transmits the reading from the thermocouple to the computer. When the steel is in a ladle, it is more or less the same equipment on a smaller scale. We call it an autosampler. 

For liquid steel, infrared is useless because you would only be measuring the slag surface temperature which is considerably cooler than the steel. After all, anytime liquid steel is exposed to air it oxidizes and slag is formed. So you have to get the measuring device through the slag (which is not always easy) and into the 1600 degree steel. That means your gonna lose whatever you stick in the steel.

I think the sublance thermocouples are around $50 a pop, the ladle thermocouples around $12. And they are accurate to +/- 3 degrees, which is good for steelmaking.

But this has nothing to do with chainsaws, so I will diminish...

Chris B.


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## klickitatsacket (Jun 30, 2005)

timberwolf)
Since then I have looked at saws and pipes with a 20k thermal imaging camera said:


> Do have a picture of this image by any chance that you could post? I would love to see it. Chowdozer is there any way you could do some stuff like this for me. Take some thermal images of the saw, maybe a before and after picture. I was thinking that your saw would be perfect for this. I would drive it up if you are interested.


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## Jtheo (Apr 26, 2009)

timberwolf said:


> Here is the data I measured during a muffler modification on my 260.
> 
> Saw is was new 3-4 tanks of gas, sharp .325 Stihl RS chain on a 16" bar.
> 
> ...



Thank you for this information. This is one of the reasons that I enjoy this forum so much.


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## chopperfreak2k1 (Aug 5, 2010)

for all the time, thought and work that went into this, THANK YOU Timberwolf


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## Naked Arborist (Nov 23, 2012)

klickitatsacket said:


> Timberwolf  Thanks for the work you did and for posting it. When I first found it, I even printed out your results. I have a copy of them in my note books.This post is also why I do not post a lot of my testing data. Pi$$ on lazy nit pickers who do NOTHING but read or who have never tried to learn on their own with out the use of some one else's money. You could easily spend a half million dollars to prove exactly what you already proved. Muffler modification reduces heat and unrestricts flow. When it comes right down to it that's all you really need. If you really wanted to get picky just run the same tests 5 times each and take averages. The chances of NASA coming up with better data that is relatively meaningful would be about the same as congress doing something relatively meaningful.



Thanks Timberwolf! 
Here it is for the masses (that's you and you) need to know about a muffler mod. I NOW SEE that the KNIT-PICKING started a LONG LONG TIME ago on here.

All these saw questions about mufflers GEZZZ. Like you never heard of a Flow Master muffler on a street vehicle? REEEEEEEEALLY?? I know for a fact you have all literally "hear'd" dem befour" WAA BAA LOL.

Grind it, fill it, juice it or drill it but always RUN IT HARD! It it fails there is much more to be learned by then.

Now back to our regularly scheduled program about port timing numbers and whose are best.


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## hdbill (Nov 23, 2012)

Timberwolf

Great info and post, really helps and explains for a whole lot of folks reading. To bad there has to be a pi$$ing contest from other readers that dont really help nothing but thier egos


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## thomas1 (Jan 18, 2014)

Bump


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## Iron Buffalo (Feb 11, 2018)

Awesome Muffler Mod Thread, Thanks Timberwolf !

I was wondering if your tests were performed with the Spark Arrestor Screen installed ?

Sorry for replying to such an old thread but this information it Timeless

Thanks

Iron Buffalo


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## ncfarmboy (Feb 11, 2018)

He hasn't been on any site that I know of in years. Saw some of his muffler work before site crash no spark screen.
Shep


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