Mufflers, Simple & Light

LAST EDITED ON Sep-11-04 AT 01:19 PM (CDT)
 
Thought some of you might like to see this. I'm sorry for the low quality pictures, my digcam doesn't focus well when the batteries aren't right up.

Anyway, numerous folks have seen my mufflers and asked about them, I've sent sketches but never seen anyone make one themselves. I won't give a blow by blow, I think the shots are pretty self explanitory. The most difficult part of this is developing the proper blank length so that there is no gap when you wrap the muffler shell. The inner "t" piece isn't that critical. The muffler is rivited together through the reinforcement and serves as the stop against the exhaust stack. A music wire "bale" is bent that holds the muffler on, no screws or clamps to come loose of mar the case finish.

LAST EDITED ON Sep-11-04 AT 11:17 AM (CDT)
 
How is the muffler held on to the engine? Screws entering from the far end I assume.
Great job on the muffler.
Jerry Bohn

Jerry, my question too until I looked at the side of the muffler in the last photo. Notice the long wire bale, it goes around the engine and is held in place by spring tension.

There is genius in simplicity, and you have solved two of my problems with older engines. Many thanks for sharing this.

Very nice Randy. Does the end plate have a step in it? to register in the end of the muffler??....Thanks

Randy,

VERY neat work! I've been brazing aluminum mufflers for my planes for 25 or more years, but that is a major effort with much waste. Minimum I seem able to braze reliably is 1/16" aluminum (dead soft, K&S works). Thinner sections burn through too easily.

You don't mention the metal thickness, but good annealed .063 or .031 can be easily worked over yr mandrels.

The end cap looks stepped to fit into the riveted 'barrel.' Is it? How is that attached to the 'barrel?' --I'd be surprised if the bail were strong enough to hold it together...

Thanks for some ideas! I'll credit the source if\when asked why I did whatever using your techniques.

Wow, Randy, that is an AMAZING piece of work. So simple-looking, it looks like even I should be able to make them. Yes, the photos are pretty self-explanatory, but could you please provide a few details? I'd second (or third) some of the questions already asked... like how thick is your sheet aluminum? How is the end-cap attached? What thickness of music wire did you use for the bail? If I knew those answers, I'd probably give it a try!

Tim

Tim,

For your Red Head McCoys you'll have to use .046" wire or it won't fiy between the head fins. Here are some shots of a Red Head muffler.

LAST EDITED ON Sep-11-04 AT 02:51 PM (CDT)
 
Greg, Lou & Tim,

The end plate is 2 pieces of .063 riveted together, the inner fitting into the shell and the outer resting against it. It is held together by the bale. In one shot you can see the flat rivet heads and drilled dimples that the bale registers into.

Lou, the bale does indeed hold it all together. I've made many of these and the bale works very well. In fact, my earlier ones were of lighter wire, (.046) but I was out the night I built this one so I used .063.

The shells are 1/32 and the inner reinforcement is 1/16. My earlier efforts were of .015 for the shell but they were not durable enough though I'm still using a couple of them.

Randy, the engines look very familiar. Am I right?
Joe

Well, A couple of 'em anyway.

There is truly a certain magic in simple solutions for complex problems. Absolutely wonderful!

"I don't know about this tuned pipe business. I practiced on that thing until my lips turned blue, and I still can't play a stinkin note."
"Homer J. Simpson"

Randy,

You've got a special touch with that kind of stuff. Takes know-how and execution. Very very nice. And, of course, I just love those old McCoys. Looks like you've got some nice ones.

I had trouble with getting one of my Red Heads started with the tunge muffler on it. Not that it wouldn' start because of the muffler, It just wouldn't start without a prime. So, I had to take it off. That particular one still needs some more time on it and suspect it will start fine with just a choke once it gets a little more broken in.

Your attention to detail is really impressive.

Best Regards,