Double barrel shotgun muffler mod

[Freakingstang]

I think it looks good. Do you notice any change (increase) in power with the double barrel muffler mod vs the previous mount bracket mod?

I think it does, but then again maybe that is because I hear more of it?! The opening I had on my first go round was about 3/8" smaller overall and thus could account for the bigger pipes having a tad more increase in power, if any. This was done before I had done any timed cuts. Although I still have the other muffler and could take some timed cuts in the future. The main reason I did it was the last big tree I took out was a 47" at 36" dbh and the saw spent a lot of time in one spot, thus burning the bark more than I liked.

I will say, it takes more of a welder to weld them to the muffler itself than the pipes together. The muffler case is extremely thin. My first mod (55 Rancher) I pop'd through the muffler a couple times.

Steve

 

[asb151]

I think it does, but then again maybe that is because I hear more of it?! The opening I had on my first go round was about 3/8" smaller overall and thus could account for the bigger pipes having a tad more increase in power, if any. This was done before I had done any timed cuts. Although I still have the other muffler and could take some timed cuts in the future. The main reason I did it was the last big tree I took out was a 47" at 36" dbh and the saw spent a lot of time in one spot, thus burning the bark more than I liked.

I will say, it takes more of a welder to weld them to the muffler itself than the pipes together. The muffler case is extremely thin. My first mod (55 Rancher) I pop'd through the muffler a couple times.

Steve

Steve, what did you finally set for flow areas? I think you said (2) 7/16th pipes and then you restricted the flow again?

When I modded my 365 I cut a .9 x .45 hole in the same spot you are and then added a bolt on deflector and screen (previously posted). It works great and the saw has noticeably more power. I am getting ready to do the 372 soon.

I also like what Ben did. It's nice and clean. It's also seems like an easier assembly than the dual pipes. As long as you have another muffler available to cut up.

Aaron

 

[bwalker]

FWIW I used two 3/4 holes. In other words I added one extra, stock sized hole.
I got the deflector off a saw that was sitting in my dealer junk pile. Skidder crunched it.

 

[Freakingstang]

Steve, what did you finally set for flow areas? I think you said (2) 7/16th pipes and then you restricted the flow again?

When I modded my 365 I cut a .9 x .45 hole in the same spot you are and then added a bolt on deflector and screen (previously posted). It works great and the saw has noticeably more power. I am getting ready to do the 372 soon.

I also like what Ben did. It's nice and clean. It's also seems like an easier assembly than the dual pipes. As long as you have another muffler available to cut up.

Aaron

Those measurements were for another saw (55 Rancher). The first outlet I did in the mounting bracket was an oval (1/2" x 1.25") Those pics were two 5/8 id pipes. That is an overall area of 1.25" vs the 1.125" that was in the lower part and the bracket.

I have a couple of the deflectors for smaller mufflers that I can take pics of, and I might be able to get a couple of the deflectors from my Husky dealer, as he is big with the loggers and is constantly getting smashed saws in.

 

[Gypo Logger]

The biggest problem with the Hoffmanized style of muffler where a flat washer is tick tacked to the front, is that it can actually set the bark on fire under certain situations, especially while cutting big wood with a dull chain.
Walkers make a real nice muffler as well with the pipes put in the right place.
John

 

[asb151]

Steve, Ben,
Thanks for the info. Both of you guys added a little more exit area than I did. I don't think I'll adjust the 365 because I am very happy with the way it runs. However, when I mod the 372 muffler though I may go larger. Especially since I plan to be running screens.
Since the mufflers are the same between the 2 saws I could experiment. Swap the mufflers and run some timed cuts to see if there is any difference. We'll see.

 

[Simonizer]

Simon, Please go slither back under your rock. You offer nothing positive.

OK, (since you said please).

 

[bwalker]

Steve, Ben,
Thanks for the info. Both of you guys added a little more exit area than I did. I don't think I'll adjust the 365 because I am very happy with the way it runs. However, when I mod the 372 muffler though I may go larger. Especially since I plan to be running screens.
Since the mufflers are the same between the 2 saws I could experiment. Swap the mufflers and run some timed cuts to see if there is any difference. We'll see.

To be honest, when I did mine there were no calculations or science used in sizing the additional port. I just added a second hole the same size as the stock one.
I dont think you can really go worng, unless you go way big.
One thing to consider though, is the fact that I do not run screens. To get a equal amount of area to mine while using screens the outlets would have to be significantly bigger.
I do know that my mod muffler nets roughly 20% so I must have did something right.
:greenchainsaw:

 

[Gypo Logger]

Here's two different ways of doing the muffler.
On the left we have a 5 year old Walkers muffler with the pipes and the lazy mans way on the right. Both are for my 385's.
I much prefer the pipes, not only for looks, but they don't set the bark on fire like the one on the right.
John

 

[StIhL MaGnUm]

I just ordered a new muffler for my 385 from Walkers last week , the one I originally got from them a few years ago got trashed last year , bolts loosened up and broke the flange off on the exhaust side .. So gettin the saw rebuilt and ordered the new muff .. Miss the bark of the ole' girl

Later Rob

 

[woojr]

Great looking job. What's left inside? Did you completely gut it? If there is a baffle like extension remaining you might make a flange (small 90) and braze it directly to it.
ALso, something I think allot of people forget about is using a oxy-acet. torch to gas weld these thinner parts. I have a cheapo mig with flux core wire (no gas) that I can hardly see. Need a cheater and larger view shield. Anyway I figured it wouldn't look any worse so I tried it. I suggest if you have a torch you'd be be pleasantly surprised how thin you can weld and control where th eheat is... Just a thought. woojr

 

[Brigham]

I've gotten huge gains from this style of tip.

 

[bwalker]

Is'nt that the dirt azz forwarder?

 

[Freakingstang]

Steve post a picture!

Sorry for the long Delay. I just got it back this weekend. This is my loaner saw. This is the one that I was describing with the two 3/8" pipe nipples welded to it. For a 55 Rancher, it runs pretty respectable! Don't laugh this was my first mod that wasn't a hole in the bracket. I thought I had actually thought of this until I saw this thread. It made me sad.....

The pics are a little on the big side, but you should be able to see most of the details.


-Steve

 

[Kneejerk Bombas]

Haha, your time would have been better spent sharpening the saw. You do know they aren't supposed to be used as a trencher, hey?

 

[Marky Mark]

The threaded pipe looks great plus you can screw on your Silencers.:deadhorse:


I guess after all these years we still have this muffler debate.

 

[Freakingstang]

Haha, your time would have been better spent sharpening the saw. You do know they aren't supposed to be used as a trencher, hey?

Goes to show why it is my loaner saw. I just got it back this weekend! The pipes have been in place about 4-5 months.

 

[Freakingstang]

Why don't you guys have sights on the end of your barrel?
Also, why an over-and-under and not a side-by-side?

Ask and yea shall recieve....


Here's my newest double barrel mod: It started life as a smashed muffler, so I didn't have much to loose to start with.

 

[Kneejerk Bombas]

Cool.
Do you have to take the cover off every time you want to load it?

 

[kevinj]

Nice pipes sedanman. I bought a 361 in March, have to wait till March 07
to modify my muffler. I am sure if I did this now, it would void my warranty.
Is that black pipe that you used?