ever make a muffler?
 

I want to hide the exhaust on my Decathalon,the engine (saito .72 ) is inverted and I havn't found a muffler that I can hide inside the cowl,like a pitts muffler. Slimline makes a pitts for a inverted Saito 100 but nothing for the .72
So what to do?
Can I make one?
I've made stainless custom exhausts for cars,
why not a plane!
My Question is, has anyone ever done this ?
What should I use ? Maybe copper pipe soldered together, or aluminum,steel?
It needs to be light and hold up to heat,also I'll need a different header or at least 90 degree fitting or two and some threaded tubing?

lets have some ideas! [8D]

Thanks, again
Chris (Moparcolt)

RE: ever make a muffler?
 

I bought a used Thunder Tiger .91 4stroke over the net and it came (surprise!) with a header that had been cut, bent to nearly 90 degree, and welded. Works good, maybe you can find a metal expert to alter one for you.
I built a boxy Pitts-style muffler for a side mounted 2stroke on a Sig Smith Miniplane. It was made of K&S sheet brass and brass tubing, with tabs folded at the bends to provide an overlapping solder joint. It was silver soldered. The vibration pretty much disintegrated it, all joints failed. Maybe riveting and soldering would hold up.
If the engine is fully enclosed, maybe the sound level will be low enough without a muffler? My planes with a muffler inside a cowl are really quiet.
best wishes!

RE: ever make a muffler?
 

Years ago I used 3/8 metel flex tubing I got from the hardware store the kind used on gas appliances. It was used to direct the exhaust on a two stroke after the muffler. The guy who helped me do this had a four stroke exhaust directed with this method on a Aronaca Champ . If I remember right the ends were held on with small hose clamps and blue gasket sealer,the high temp silicon. he took a dremal and cut a small slit in the end of the tube to aid in clamping and also knarled one end of a solid pipe to help grip the tube onto the pipe.

RE: ever make a muffler?
 

Thanks for the ideas. I saw some mufflers at LHS today and they seem to be made of aluminum with welded joints. I can't weld aluminum but I thought i might be able to use some thin guage steel and braze the joints, I just need a couple different sizes of tobing and maybe some sort of 90 degree threaded adapter for the connection to the motor.[8D]

RE: ever make a muffler?
 

RE: ever make a muffler?
 

well this is what i tryed to do in post above loool if you try these people http://www.justengines.unseen.org/ e-mail him and tell him what you want and he can point you in the right direction very good people and great at shipping ! :D

RE: ever make a muffler?
 

If I were attempting this, I'd use phosphor-bronze brazing rod. I've used it for refrigeration tubing and it never fails. You could get it at a wholesale house that deals with heating/cooling. It takes a lot of heat but bonds brass or copper perfectly. You have to get copper just to the point of red hot to get it to flow, at that point it bonds and is self fluxing.

me
 

can any one tell me what 3 channels on an electric rc plane means?

RE: me
 

well I 'm giving it a try. !/2" electrical tubing, 5/16" brake line gas welded with a good old coat- hanger. Here's the first picture.[8D]The 5/16" are pushed all the way into the larger tube and they have 8 small holes drilled in them like baffels. I still have to make a nipple to connect the muffler to the motor and pu in a pressure fitting. Then I will have to get a 90 degree fitting to go on the motor.

RE: me
 

Getting closer! I drilled and tapped the preasure fitting and put in a 3/8 tube for the connection to the motor. I still have to weld it up. I'm thinking of making it larger,I think 7/16 is the next size up in tubing, but I didn't have any on hand, and it's 11:30 at night ,so it will have to wait till tomorrow. But here are the pics. I'm thinking that if this thing actually works I'll have it Jet Hot coated to reduce the heat inside the cowl. The headers on my race car are coated with this stuff and it is awesome,you can put your hand right on the pipes within 5 minutes after you shut the motor off.[8D] I still need a 90degree fitting, maybe the ones they use to adapt to flex would work? anyone know who makes one for a Saito .72

RE: me
 

Heh, the custom muffler on my 25% Suk26 consists of a header t hat goes straight into a 6oz tomato paste can with two outlet tubes.

Clever idea for an in-cowl muffler. (Unfortunately not mine).

RE: me
 

Well, I test fitted the muffler, I connected it to the engine with a short piece of saito flex pipe and held it away from the firewall with a small piece of stainless wire around the cylinder.
I sent the muffler to Jet Hot To have it Ceramic Coated it will be back next week andI'll put some shots on so you all can see![8D]

RE: me
 

How much does it weigh for the time being ?

RE: me
 

Well guys it's finally done!
My homemade muffler came back from Jet Hot,I had it coated with their "Sterling" ceramic metalic coating and it looks GREAT! The coating not only makes it look good it disipates heat way faster and is corrosion resistant/proof.The cost was $25 + $12 shipping and insurance. Well worth it in my book.
I havn't had a chance to weigh it but it isn't any heavier than the stock manifold/muffler
I'll try to weigh it tomorrow to find out what it really weighsfor sure.
Here are some pictures, what do you think?[8D]

RE: me
 

Theese show it on the plane. It is attached to the motor with a small piece of saito flex.I only used a couple of inches so I can use the rest on another project. I also made a polished aluminum firewall to protect the wood just in case there is extra heat, because the muffler is pretty close to the firewall, another reason for the coatting, and it looks good too! Now I just have to find a polished aluminum spinner. [8D]

RE: me
 

Great job [sm=thumbup.gif] !

RE: me
 

I weighed the muffler today 1.6 oz. the Saito one was 1.4 oz.

RE: me
 

So, is the muffler still holding up?

RE: me
 

the muffler is ok! the plane went down into a tree a while ago, though!