Brodak Tongue Mufflers - fit what?

[Keith Miller]

Hi all -
I posed these questions to Brodak, and they deferred me to this forum until their knowledgeable person returns from vacation.
Maybe one of you knows?
Their web site has no specifications or drawings for their products (which is the norm, I guess; few suppliers in our hobby take the time to really describe what they're selling..)

And yes, I live in an area where we need to reduce noise so as not to loose our precious flying areas. So please don't ask me why I'd muffle a classic open-exhaust engine.

- Will the TM-5 Fit the Super Tigre C35 (non-bearing combat)?
- Which tongue muffler would best fit an OS Max-H 35? This engine has rounded exhaust stack with no ears similar to the McCoy Red Head 35 but a little wider.
- Would any of the TM-19 through -21 fit the Torpedo 19? Its stack is narrower than the McCoy Red Head 19.

Thanks in advance!!

Keith

[Perry Rose]

I just ask for a muffler that fits the stated engine. Most are Big Art brand mufflers.

[Dan McEntee]

    The ST.35 combat engine wasn't designed for mufflers, so you will have to see what fits the exhaust stack and then rig up a strap tp hold it on. Have you got some flying buddies that are mostly stunt fliers with a good collection of vintage mufflers? You could make a tongue muffler out of the Dubro exhaust extension stock and have some one machine it to precisely fit the stack. Then cut it to desired length. Rig your strap or retaining spring on the machined end. Then drill and tap some 4-40 holes on the other end, one on each side. Cut a plate that will bolt to that end, and shim it out with some flat washers for exhaust clearance and you have a muffler. Any existing muffler that has enough material to be machined out can be fitted this way also.
   HAPPY NEW YEAR!!
   Dan McEntee

[Peter in Fairfax, VA]

Dan,

Thanks for weighing in on tongue mufflers, as well as the utility of the Du-Bro stock.  Some of our best machinists in our local club, NVCL, have also mentioned that stock.  Others have machined the whole thing from bar stock.

Basic question:  How do you plug the end of the Du-Bro stock?

I'm also after a couple of tongue mufflers to fit the Veco .19 series 100 engine.  My machining skills are limited, I have done very few milling projects.  At best, I'll carefully measure the exhaust opening to create a set of specs.

At the muffler / engine interface, a good design often incorporates a flange that fits either inside of outside the engine exhaust port.  There was a firm, Slimline, that made fitted tongue mufflers.  While I have a picture of one for the Veco .19, buying one is very difficult.  Desert Engines owns the tooling and Intellectual Property, but will likely focus on making mufflers for their own engines, according to them.

As far as mission purpose, the Veco .19 muffler would be a huge help in our club's efforts to train new C/L fliers.  What we've found is that folks who wander to our field or contact us via AMA are the ones that have a true interest.  Presenting C/L at a community event, even one aviation oriented, is more of a "one and done" situation.

Peter

[Perry Rose]

Cap the end with a piece of flat stock and two screws.

[Dan McEntee]

Dan,

Thanks for weighing in on tongue mufflers, as well as the utility of the Du-Bro stock.  Some of our best machinists in our local club, NVCL, have also mentioned that stock.  Others have machined the whole thing from bar stock.

Basic question:  How do you plug the end of the Du-Bro stock?



Peter

      Read my post again. The two hol3es you drill and tap opposite the exhaust are used to hold a plate. You can shjil the plate out t varying degrees to tune the exhaust, or just drill holes in the plate to let the exhaust out, or a combination of both I've seen some Windy tongue muffler capped solid on the end and a slit cut in the top and bottom for the exhaust to exit. Lots of ways to do it.
    HAPPY NEW YEAR!!
    Dan McEntee