jcoolhand

I'm currently in the process of builing a P-40 running a Magnum XL 80 4-stroke. I'm trying not to cut the cowling to fit the exhaust pipe but am running out of idea's quick. Is there any other options other than fabricating a new exhaust pipe? Appreciate any advice....

MinnFlyer

My Feedback: (4)

I have put exhaust pipes inside of cowls many times with no adverse effects. Just make sure that it's not too close to anything, and that the exhaust isn't being blasted against anything. You can either use an exhaust diverter to redirect it, or protect areas with Aluminum tape.

DBCherry

My Feedback: (4)

Keep in mind, the engine requires cooling which means cutting openings into the cowl. For that engine, I'm thinking the equivalent of a couple of square inches of inlet, and twice that for outlet. Otherwise your engine is going to overheat.
Dennis-

jcoolhand

I appreciate the advice, but my problem is actually the exhaust itself. The Pipe from the engine to the muffler is at an angle that will not allow the cowling to cover it, without it either being bent, or cutting the cowling. I was wondering what other alternatives there were so I don't have to cut the cowl. Any techniques on bending an exhaust pipe? It's only about 2 inches so there isn't a whole lot of room to work with.

moparcolt

My Feedback: (2)

can you use flexible exhaust tubing and bend it to fit.
I know exactly how you feel, i just went through this on my decathalon.I ended up making a muffler and using a piece of flex to connect it to the motor. If you do a search for the topic ever make a muffler? you can see pictures of how I did mine. I'm sure your situation would require a little different approach , but check it out it may give you some ideas[8D]

Jimmbbo

TopFlite makes a firewall mount muffler that I'm going to use on my TF P-51 -

http://www2.towerhobbies.com/cgi-bin...?&I=LXHY74&P=K

They also make adapters for several engines, but unsure if yours is among them. If it is not, if you can figure a way to get the exhaust from the engine to the muffler, that might solve the problem....

HTH

Jim

Capt Jim

My Feedback: (168)

I had the same situation with an OS four stroke setup. I was very much afraid to bend the exhaust pipe, fearing that it would either break open, or kink closed. In an act of desperation, I placed one end of the pipe in a big bench vise, plugged the lower end with a dowel, filled the pipe with fine sand, and then proceeded to heat the pipe with a regular little propane torch until it became red hot. I then gently bent the pipe to the required angle...being careful to avoid bending or disturbing the threaded ends...and the total bend was not very much of an additional bend, and let it cool. It worked beautifully. Some more experienced modelers may be able to fine tune this prodedure by talking about re-tempering the pipe etc, but I don't know the appropriate procedure and so I just used it as it was. It continues to be just fine....years later.
Good luck with yours.

jcoolhand

Hey thanks all so much for all your ideas! I finally figured out a way that works so far. I used Exhaust stack flexible hose to connect the exhaust manifold to the muffler under the cowl. So far it's ran just fine with no leaks in the exhaust so far. I am considering going to the firewall mounted one as suggested but we'll see if this works through a few flights. I'll try and get some pic's on here so others can maybe use some ideas too (Also to show off my new P-40). Thanks again to everyone!

Jcool