Muffler Mod

[mikefrommaine]

Here's how I did my latest muffler mod.

I have been using the husky deflectors to add a second port. But they are expensive,and I'm cheap. I used a piece of 1/2" aluminum electrical conduit as the deflector.

I saw mastermind and others using silver solder instead of brazing but I had an oa torch and have been looking for an excuse to learn brazing. The idea of a pipe outlet in front of the cat was 'borrowed' from mastermind . Sure beats trying to cut or drill out the cat.

.. So here goes, questions, comments and concerns?

I used sketchup to measure the area of the exhaust port. I also made a template of the deflector and used that info to make a template the exact size and shape I wanted.




Here's the template, exactly .47 square inches, which when added to the existing outlet gives me a total of 85% of the exhaust port.

 

[mikefrommaine]

 

[mikefrommaine]

You can see how choked up this muffler is

 

[mikefrommaine]

 

[mikefrommaine]

My first attempt at brazing

 

[mikefrommaine]

A little paint does wonders

 

[mikefrommaine]

On the saw

 

[Michael Golden]

Looks stock! Nice job.......

 

[StihlHead]

I do shark gill slits and rivet on a Husky deflector over a screen (need that here for fire season). No torch needed.

But nice job! Wojo wants $125 for mufflers re-welded like that on Ebay.

 

[mikefrommaine]

That is a downside to this style muffler mod... Next time I'm going to extend the pipe a little and pick up a pipe spark arrestor like on the stihl cut off saws.

 

[mikefrommaine]

Wojo wants $125 for mufflers re-welded like that on Ebay.

I hadn't seen that:

(broken link removed to http://www.ebay.com/itm/Custom-Stihl-361-Power-Ported-Chainsaw-Muffler-By-WOJO-/231044337736?pt=LH_DefaultDomain_0&hash=item35cb50d048)
Up for auction one 361 custom dual port muffler. What is very unique about this is that all the steel that is added to the cover is stainless steel. I made this myself and it is all welded. A very complicated welding process where steel wire is introduced to stainless steel pipe.



So complicated it took me, who has never welded anything, ten minutes to figure out how to get a pipe to stick to the muffler LOL. Total cost, about 35 cents.

 

[MasterMech]

]very complicated welding process where steel wire is introduced to stainless steel pipe.

Sounds like a MIG gun or TIG, or Gas welding to me. TIG would do a real nice job on the muffler for sure. Not that complicated but the equipment is very expensive compared to brazing.

What kind of torch did you use Mike?

 

[clemsonfor]

Nice

 

[DexterDay]

I have a "round" cone type screen if you wanted one? Took it out of a small 2 stroke Genny.

Nice job though. Is that on the 254xp? Or 359?

I have a couple I'd pay for you to port? With paint, that's a fine looking job. In my opinion.

Oh, and I need no Screen. 99.9% of all my cutting is on my property now.

Again, nice job....

 

[NortheastAl]

Nice clean work on that mod.

 

[mikefrommaine]

What kind of torch did you use Mike?

I've got a harris Oxy/Acetylene port a torch. Picked up cheap on CL a few years ago. I picked up a #0 welding tip for it; probably would have been better off with a #1.

(broken image removed)

 

[mikefrommaine]

I have a "round" cone type screen if you wanted one? Took it out of a small 2 stroke Genny.

Nice job though. Is that on the 254xp? Or 359?

I have a couple I'd pay for you to port? With paint, that's a fine looking job. In my opinion.

Oh, and I need no Screen. 99.9% of all my cutting is on my property now.

Again, nice job....

It's on a 359. I'd stick a pipe on the side of a muffler for you but the cost of shipping both ways it might not be worth it? Silver solder seems to be popular over on AS and all you need is regular propane or MAPP torch.

 

[smokinj]

Nice work and good touch on the SS.

 

[clemsonfor]

Heck u van put it in a padded envelope for what $8 each way?

 

[Tinder]

Here's the template, exactly .47 square inches, which when added to the existing outlet gives me a total of 85% of the exhaust port.

While cutting that portion out of the muffler makes sense, why choke it using the 1/2" EMT? Assuming 1/2" is the ID, 3.1459 * (.25")^2 = ~ 0.1966"^2.

 

[mikefrommaine]

While cutting that portion out of the muffler makes sense, why choke it using the 1/2" EMT? Assuming 1/2" is the ID, 3.1459 * (.25")^2 = ~ 0.1966"^2.

I was wondering if anyone would catch that

I had been planning to use an old broom handle I had. But at the last minute I chickened out because it is very thin wall and I was worried I'd burn through it. I guess I'm not very good at mental math and never double checked the area of a 1/2" pipe

Oh well I'm going see about make the original port a little bigger or cut off the pipe and use a bigger one.

This one looks better anyways

 

[mikefrommaine]

The enemy of good enough is perfection

I had the new piece all done and should have stopped but wanted to make it flow into the muffler a little better... Ended up overheating a section and all the filler flowed out leaving a big gap . In my attempt to fix it I burned through the pipe

Ended getting it all filled in and was able to fill the hole, but its definitely not easy to fill gaps when brazing a thin wall pipe to the muffler. Definitely easier to do it right the first time.

Here it is almost ready for paint.

 

[mikefrommaine]

The magic of flat black paint

 

[mikefrommaine]

This is the first time I actually calculated the optimum exhaust size. In the past I drilled a couple holes and covered it with a deflector... Hadn't realized how big the outlet really needs to be. This pipe is about 70% of the exhaust port. Can't wait to try it out.

 

[infinitymike]

Pretty cool mike.
Like they say " paint will make it what it ain't "

Did you try it out yet? What about re-tuning it.