I have a Byron P-51 with basically a straight pipe for a muffler.
I have heard of the purrpower muffler, but have never seen one.
Do I need to try to locate one, or is there another muffler that would fit and quite it down.
There's only about an inch between the engine and firewall.

what typpe of motor are you flying with? The Purr Power is part of the mount for the motor. It would require a modification of your firewall mount I believe. http://www.ironbaymodelcompany.com/
http://www.ironbaymodelcompany.com/i...ionSystems.htm

Hi Pete,

Having tried a Byron Purr Power muffler in a byron P51 I can tell you that you might want to consider another choice. The muffler was designed around the A&M Sachs 3.7/4.2 engines. Later I believe Byron had a purrpower for the 50cc Quadra as well. Lots of power and lots of Heat! The muffler as RamBro says is a part of the motor mount and was intended to fit in place of the Byron Reduction drive. The muffler/mount is about 8 inches long and about three inches in diameter. We could not get enough air flow around the mount/muffler with out turning the nose of the Mustang into swiss cheese. The purr power worked fine in the Corsair and P 47 because of their big cowlings and lots of airflow. Not so with a P51 with its narrow nose.

I suppose it could be made to work but there are better,lighter mufflers out there that would do a good job for your application. You want to keep the nose as light as possible to avoid having the plane nose-over as you are taxiing/taking off.

Hope this helps

Carlos G

It's a Quadra 42, not real powerful, but it flies nice, just loud as hell.
I thought Iron Bay was out of business to modelers, as they have a military contract or so I heard.
Tried to conyacy them a few years ago and they never responded.

Maybe there are some aftermarket mufflers I could get to fit?

Thanks for the replies,

Hi Pete,

As I recall the Q42's muffler mounted to the back of the cylinder similar to the Q35. It maybe that you will have to modify your straight pipe to accept a cannester type muffler. Again the issue is the heat of the muffler if you try and conceal it inside the fuselage.

B&B use to offer muffers for the Quadras. With a change of ownership and looking at their website I havent seen them listed last time I looked.

My suggestion would be to find a late model engine, pick your alphabet brand,(DA, DLE, OS, or XYZ) in about the 50cc displacement. Nearly all of them will be lighter, generally more power, smoother, and most come with a compact muffler of some sort. The Mustang will fly better for it. The Byron models seemed happiest with about a 50cc engine. We tried Sachs 3.7 & 4.2 and I least I found the extra weight verses the gain in power seem to hinder the overall flying qualities of the planes.

Tatone use to offer cast aluminum mufflers but need to be packed with some kind of media ( We used copper pan scrubbing pads) to try and dampen the exhaust note. The media would tend to blow out after a while or the muffler would shake apart. You may be able to find some on flea-bay..

Hope this helps

Carlos G

Yes, you,ve given me a few things to consider.
The Quadra exhaust does come out the rear of the cylinder, 1 1/8" away from the firewall.
Even if I went through the firewall, I'd run into the wing.
I like the plane, flies very well and the big 4 blade prop is very cool.
Not fast of course, but it is just a good flier.
Can't believe how much static thrust that 4 blade prop puts out.
Doesn't translate to speed though, too bad.
Are the four blade prop blades hard to come by?
I only have the one set.

Hi Pete,

Byron Scale Prop looks great but you loose allot of energy driving the fourblade prop. Prop blades may be hard to come by should you break one or more. Again you would need to visit Flea-bay or similar sites to find some more. The blades are not very stiff and have lots of drag because they are so thick, especially towards the tips. If you want to have decent flight performance you should consider going to a direct drive, two-blade prop.

There is another thread which I believe was in the Electric Flight forum? about someone converting the Byro-drive to electrics. One of the problems he found was that the V grooves molded into the prophub would distort and generate vibration in the drive. So instead of a true round prop hub pulley, you would end up with flats between the reinforcing spokes of the molded prop hub that caused allot of vibrations. His solution was to machine from aluminum a new belt pulley and installed it inplace of the original v-belt pulley. He said it eliminated a great deal of the vibration in the redrive system.

For me at least my choice would be to go the direct-drive route and get away from the redrive entirely. Once the engine is running you cant see the blades anyway

Good luck with your Mustang

Carlos G