a70eliminator

Sorry for the crappy little pic tried to resize with no avail.
See attached photo. Does anyone know anything about this muffler good or bad, whats the flow through design accomplish?

Gray Beard

My Feedback: (-1)

I'm pretty sure John will know but I just call it LOUD!!! Someone gave one of my young students an engine with that muffler on it and I can't stand to be in the pit with him when he fires it up. It seems to work just fine but not as a silencer.

a70eliminator

Thanks, I don't get the design. It's like a hollow tube with a jacket all around it, the gasses exhaust into it's outer jacket and there are only about 4 tiny holes inside where the gasses can escape into the airstream, thought it may make a great smoke muffler.

RCPAUL

My Feedback: (1)

Its a SIMCO flow through. Made in Massachusetts. i got a tour of the factory a very long time ago. The owner was Jimmy Simonian (sp?) He made various sizes and types, with adapters for most engines of the time.

Paul

Gray Beard

My Feedback: (-1)

I don't get it either but it could have been a number of reasons. Lighter weight? Cooler running? Expansion chamber design? When the engine is running the muffler note is very high pitched and ear piercing. It isn't bad once the plane is in the air but when the kid would come out to the field with me we would make our pit area as far away from the other guys as we could. As far as performance goes it was pretty good but I never compared it with the same engine and a different muffler. It was on a .46 engine, brand I don't recall. Give it a try, it works and looks cool.

RCPAUL

My Feedback: (1)

Several companies made flow-thru mufflers back in the day. The theory was that the air flowing through the center would create a low pressure, pulling the exhaust out, reducing back-pressure. Iowned one made by Kavan at one time. Yes, they were louder than a normal expansion muffler. But remember, back in the 60s and 70s noise was not as much of an issue as it is today.

Paul

JohnBuckner

My Feedback: (1)

I beleve Davis Diesel made a line of strap-ons called Soundmasters that may have also included a flow through. I think I got some buried somewhere and even one that included a primer port, pretty cool for acheving that perfect state of prime.

I can imagine many theorys but many may have just been wishful thinking. To my way of thinking a muffler has two jobs and that would be to control the rate of gas expansion and slow the outlet pressure to acheve efective muffling. Ya probably just more wishful thinking also

A tuned pipe is an entirely different goal of course and that is to cause a back pressure wave to strike back at the combustion chamber just at that precise moment when on a two stroke the exhaust and transfer port(s) are open, packing more of that combustable stuff in that chamber and making the magic.

John

Live Wire

Yup we could even target practice with out getting put in JAIL

JollyPopper

My Feedback: (6)

Back when Moby Dick was still a minnow, Super Tigre (the old Italian Saturno engines) and HP both supplied their engines with flow through mufflers. I don't know if they really did anything magic for the engines, but they sure ran well. I still have a Super Tigre .60 and an HP 40 wiith flow through mufflers, but I never ran them with anything other than what they came with, so I don't know if they made them run better or not. They looked cool and were pretty loud, but who cared then? I still run the HP .40 on a 4*40 and it handles the plane well.

Rodney

Fox also sold some of their engines in the late '50's and early 60's with a flow through muffler. The manufactures touted them as the best way to keep the idle rpm down and still not rob power at the upper end. Yes, they are quite a bit louder than most mufflers. When mufflers became mandatory at many clubs, modellers complained of the big power loss most mufflers of that time caused. Prior to mufflers, there was usually a sliding plate or device to close off a portion of the exhaust opening as the throttle was closed. This was necessary to retain the heat required to keep the glow plug lit a low rpms.

red head

A small rubber/ silicon tube ( about 1 1/2 " ) extension on the out let sometimes takes the sharpness out of the sound. Sometimes it even makes the bearable. ENJOY !!! RED

aspeed

Our club banned them  in the 1980's I guess because they were too loud.  I had/have one that I tried quite a while ago.  I didn't think it was that loud but it had kind of an extra purr to it.  I wanted to use it back then on a converted control line motor. Rules!?&%

countilaw

Does anyone know the part number for the muffler for an O.S. Max .60 SR ?

Frank

Gray Beard

My Feedback: (-1)

You can go into the glow engine forum then into OS support and ask Bax to be sure but I think if you just go to Tower you can buy a new muffler for any of the OS .60s or .61s and the muffler will fit your engine. On something like that with an older engine I like to ask before I order though. Hate sending stuff back.

JPMacG

My Feedback: (2)

I have a 50 sized Soundmaster on my Enya 50SS. The one I have is not flow-through. It is excellent! Very quiet and, if anything, more powerful than the OEM muffler. I have a Fox 74 in need of a good muffler. John, would you happen to have a 75 sized Soundmaster and would you care to sell it?
Thanks

countilaw

Gray Beard, I contacted Tower but no joy. All I got was a form letter thanking me for contacting them and send my name, address and phone number for their records. Oh well.

Frank

aspeed

Just scare up something that will fit.  The newer ones usually are quieter and just as powerful as long as they fit.  Mac's has some aftermarket ones as well as Bisson Jett maybe, etc.

landeck

My Feedback: (1)

If that is an OS .60 FSR the later OS 60 size mufflers will not fit. What will fit is a Fox .61/.74 tilt up/tilt down muffler. You can order either style directly from Fox.

Bruce