Muffler mod pics

[lgh]

Here are a couple of pics of my 345- modded mufler

 

[lgh]

Still trying

I guess that link did'nt work.

 

[lgh]

Muffler pic

modded 345 muffler

 

[lgh]

Reinstalled

modded muffler

 

[lgh]

Thanks

Thanks for the help RockyJSquirrel ,still need to figure out how to post more than one pic at a time. LOL

 

[Toneman]

Nice muffler mods, Igh.
Did you do it yourself?

 

[lgh]

Mod

Yes Toneman I did the mod my self.Wife was'nt looking when I took the pics, but she thought I had a screw loose when I took new saw apart.I only have about a gallon of gas through the saw and I,m impressed.

 

[Kneejerk Bombas]

Nice work!
I'm glad to see the screens covering the holes, nice touch.

 

[jokers]

Hi lgh
I have to agree with the others in complimenting your work. How did you attach the screens? It could definitely be my eyes, I didn`t even notice the screens the first time I saw them, but they resemble the strainers you might see on a faucet.

Did you see a nice performance enhancement after the mod?

Russ

 

[lgh]

mods

HI jokers ,yes there are screens in the tubes. I work for a patternshop and we use these to vent core boxes used in the casting industry. They come in differnt mesh size and OD size. The ones I used are .750 OD .687 ID #24 mesh. Just press fit inside .750 ID tube. I curently have the original outlet blocked off just useing new ports,and I think the saw runs stronger.I have caps made so I can put it back stock and run timed tests when I get a chance.

 

[Doug01]

I think that is the first one i've seen with the ports having screen in it like that. I was going to post a question to see if anyone used screen over the ports like that or if theyput screen over the exhaust port. So there's my question to everyone and then also does it hurt anything to have the screen over the exhaust port, because that is what I did to my 350 when I opened the top. I just got the wife a digital camera so when I figure out how to post pictures on here I'll throw it on.

 

[rbtree]

lgh,

I think you may have made your ports too large. Mine has two 9/16 ports, and that is plenty. The saw has incredible power. But perhaps the mesh reduces the flow a bit. I think my 372 ports are about that size, and the 3120 are 0.90 each

Some backpressure is needed, and too large a port area could cause a power drop off. The formula seems to be to have 1 to 1.25 times the cylinder exhaust port area. I recently posted 1.25 to 1.5 as I thought Ken Dunn had once said that.. Could be, but I searched for the old threads and couldn't find the info. Someone else thought that 1.5 might be too much.

 

[lgh]

mods

rbtree if you figure the 30% loss for the screen I am still about 100% of exhaust port.

 

[bwalker]

Roger,I do n0t think a blanket size like 1.5x can be applied to all saws. Cylinder size, port size, ignition timing and port time/areas all come into play. FWIW I know my 260 was really sensitive to changes in port size and ran like crap when the port size was increased too much.

 

[Gypo Logger]

This is a true story, I saw an 038 get a 12ft. powertune. It was droped off a ladder by the guy on the 30 degree ladder I posted not to long ago. Anway, the muffler was smashed in, but did it ever cut after the seam in the muffler was broken. So to get the same effect, just take a ballpeen hammer to the muffler of any boat ancor and watch it get up and talk.
John

 

[rbtree]

lgh,

Any chance you could send me two for my 3120XP-G. Ports appx 0.9 ID?

I'd feel better having screens over those huge ports, mainly to keep crap out of the muffler. And I could do a cut test to see if the restriction slows the saw down...I'd guess not, as it is one mean machine.

Let me know your costs if are willing to do this.

 

[lgh]

Mods

rbtree I will check tomorrow and see if we have anything that size.I will be out of town for a couple days,wont be back on puter till Monday.I will let you know if we have anything that size.