I have a saw that has a similar diffuser and the hole diameter can be checked with bendable wire then do the math. Step drill up to a 1/4" hole to start and run it. The low speed jet will need to be adjusted.
Husqvarna 44 Muffler mod?
- Thread starter Gareth83
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Find a wire (bend it 90 degrees) diameter that just fits in the small diffuser hole and then find the area of that diameter and multiply by the number of small holes to get the total diffuser area.
what's the diffuser area got to do with anything though?
I know roughly the area of the port at the piston, i then simply calculate 80-85% of this and that is what the area of the actual muffler exit should be?
What am I calculating the diffuser are for now? I know by sight it is not larger than the exhaust outlet at present
I know roughly the area of the port at the piston, i then simply calculate 80-85% of this and that is what the area of the actual muffler exit should be?
What am I calculating the diffuser are for now? I know by sight it is not larger than the exhaust outlet at present
From what you have said in your previous posts, I understand that the diffuser (tube that goes from the back of the muffler to the front has holes in the side. So all the exhaust gas has to pass throught the small side holes to be able to finally pass through the muffler outlet. If the total diffuser side hole area is less than the muffler outlet then opening up the muffler outlet wont help.
Maybe I am butting in here on your thread but I find a step drill the best tool to make round holes in mufflers. I don`t see why you would have to rip your muffler open to accopmlish a simple port job on this saw.
Pioneerguy600
Pioneerguy600
Because the restriction is inside in the form of the diffuser as discussed above
All we usually do is drill another hole through the baffel from the backside and another hole througt the muffler housing itself , don`t see where a dremmel is needed. I have done 45+ muffler mods without using a dremmel so was just curious where a dremmel was needed.
Pioneerguy600
woodyman
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I put a pipe on mine right where the baffle was.
I had drilled a hole in the front of the muffler that was sealed up.
well I went around the weld join with the dremel and guess what?? It still wouldn't split in half!
It looks as if the diffuser is holding it together.
Been trying to force it open but done nothing but dent and damage it.
Wish I never bothered! There is a silencer also prior to the existing outlet. What I should have done was capped this off and just drilled a bigger hole elsewhere.
I now need another muffler, anyone got one going spare?
It looks as if the diffuser is holding it together.
Been trying to force it open but done nothing but dent and damage it.
Wish I never bothered! There is a silencer also prior to the existing outlet. What I should have done was capped this off and just drilled a bigger hole elsewhere.
I now need another muffler, anyone got one going spare?
well I finally got round to cutting it up and have a brand new one of the same ready to mod.
From the picture can I simply
a) weld up the existing exit and drill a larger one anywhere on the box thus bypassing the silencer
or
b) just drill an additional hole elsewhere so some of the gases will exit via the existing and be silenced somewhat and some will exit via the new hole
My guess is a would be more efficient if somewhat louder?
From the picture can I simply
a) weld up the existing exit and drill a larger one anywhere on the box thus bypassing the silencer
or
b) just drill an additional hole elsewhere so some of the gases will exit via the existing and be silenced somewhat and some will exit via the new hole
My guess is a would be more efficient if somewhat louder?
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Gareth, if that were my muffler, I would drill a hole the same diameter as the existing muffler outlet hole in the same axis (I think earlier in this thread you called it parallel to the pipe).
Saw Dr.
Junk Collector
WOW, this sure got complicated.
I'd take said dremel, and slice the inner baffle tube from the inlet side of the muffler. The halves should seperate nicely then. Once it is apart you can remove everything from the inside and make two steel sleeves so the muff won't crush from the attachment nuts. You may find that no more outlet area is desired after this. I would try that first. If you still feel you need more, then you can add a port.
I'd take said dremel, and slice the inner baffle tube from the inlet side of the muffler. The halves should seperate nicely then. Once it is apart you can remove everything from the inside and make two steel sleeves so the muff won't crush from the attachment nuts. You may find that no more outlet area is desired after this. I would try that first. If you still feel you need more, then you can add a port.
To do that though I'd still need to cut the outer surface to split the casing which seems too much effort on a brand new muffler considering I'll have to pay someone to weld it all back up.
Drilling an additional hole as Scott suggests would be easiest method but I'd be concerned exhaust gases would be competing to exit the two holes.
Welding the existing exit and drilling one larger one seems the most sensible option surely?
If you want to think about the back pressure inside of the muffler then an additional hole would lower it. I wouldn't worry about the pressure competing to exit the two holes. Make it easy on yourself and lower the back pressure and see if when you retune your saw runs better. I'd bet it runs much better.
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