Lycoming muffler

[Palm Bay Airboater]

I know this has been talked about a lot, but I have a question about mufflers for a Lycoming engine. I read somewhere that I have to run the bullet muflers because the oval mufflers have too much restriction, is this true. Also I know I need stainless mufflers, so does anyone know where I can find some stainless bullet muflers.

Dennis

 

[dblj006]

I used the Magnaflow 4x9 ovals with 2-1/2 in-out. They are stainless
and free flow. I called Magnaflow tech to make sure and they guaranteed
100% free flow. They were cheap too. I linked off their website and ordered them online for $70.00 a piece.

Not only do I like the sound I swear my 150 runs smoother and a whole lot cooler. It will shut right down even after hard running. Go figure.

Try the website they have a bunch of different sizes.

http://www.magnaflow.com/

 

[Anonymous]

dblj, before you put the mufflers on you were over-scavenging the cylinders ..... the engine was running too hot on the exhaust cycle. When you put the mufflers on you added beneficial shock waves to the exhaust and cooled the exhaust cycle down. Your valves thank you, and that's what makes it shut down now like it should.

Very few things can be as hard on exhaust valves as a straight pipe.

feather

 

[woodswoman]

I run a set of Borla 2-1/2" in/out Stainless offset mufflers on my Lyc 0540. With the mufflers & my Power Shift, I run about 86 db at 50' at 1800 rpm on a plane.
Iv'e had the Borlas on about 3 years with no problem other than less noise.

 

[ONA540]

I bought my mufflers from Jr. Jurnigan. I trust him because of his knowledge of Lycomings. They are 3" in/out, polished stainless, haven't put them on yet, but will this week.