Is there only one type of muffler for four stroke engines?

you cant use something like a pitts on them can you, to keep the profile down?

just wondering ... srt5321.

Four stroke mufflers are smaller than two stroke mufflers. It usually works out that you don't need a pitts muffler if you mount the engine on its side or at a 45 degree angle up or down.

They do make them but I've never seen one at the flying field.

Jim

Slimline make a range of "Pitts" style mufflers for four stroke cycle engines - with and without smoke.

Dennis

I have a Slimline Pitts style muffler on my OS70. Works fine but has a distinct sound. Maybe a little louder than the stock muffler.

thanks for the help, guys..

If noise isn't a concern, you don't really need a muffler at all. A piece of pipe or even just the stub will work fine, but will be quite loud. I'm running both my YS.91's with no mufflers at the moment.....just an exhaust deflector zip tied onto the muffler stub. I don't know how long the deflectors will last though....one of mine has just disintegrated. Of course, if you need muffler pressure though, you're stuck with one.

noise would be a problem, i was thinking of something more concealable under a cowling..

You could try a "secondary" muffler and use a piece of silicone tubing to connect to the header pipe. Just Engines sells several of these. Or you could get the Top Flite in-cowl muffler meant for their scale planes and do the same thing.

4 strokes, in general, are not finnicky about muffler volume and back pressure the way 2strokes are. You'd be okay with just about anything plumbed onto the exhaust header.

I wonder if you could get a realistic benefit from 'piping' one?

Four strokes are not as responsive to tuned pipes as two strokes are. There's not a very good payback to it concerning to expense and effort to install one.

Jim