OS Rotary engine
 

I have a new in the box Rotary engine and I have a couple of questions before I install it on my plane.

1. The manual refers to a pressure port on the muffler but mine does not have one. Does this engine need a pressurized tank?

2. What is the pressure port for on the crankcase? There is no reference to it in the manual.

3. Are accessory mufflers or extension pipes available for this engine? Due to the fact that the screws mount the muffler in one fixed location I am really going to have to hack my model up to use the muffler in it's stock configuration. (Not desirable.)

4. What is the preffered Oil mixture/ Nitro content for this engine. I use 15% Nitro with a Castor/synthetic mix in my other engines. Would this be suitable for the Wankel style engine or does it seem to prefer a higher or lower Nitro content?

I bought the engine to install in a .30 size plane that has a large round firewall and is modeled after a plane with a radial engine. The Rotary would be perfect in it and give it a very scale appearance but the muffler is gonna probably cause me to rethink this if I can't do something with it. I would really appreciate any ideas you might have.

RE: OS Rotary engine
 

You don't need muffler pressure, but it does eliminate changes in mixture as the fuel level is lowered in the tank. It's a simple measure to drill the muffler and add a tap.

The nipple on the crankcase is a drain for excess oil that gets into the counterweight chamber. Just add a piece of fuel tubing to let the oil drain out the bottom of hte cowl.

There are no other muffler options available from O.S. We're not familiar with any after-market accessories for the engine.

Any good-quality airplane fuel is fine. We strongly recommend a synthetic/castor blend for best performance. Your fuel should be fine.

RE: OS Rotary engine
 

Thanks Bax, one last question, do you think I could get away with building a custom muffler for the engine? something along the lines of a pitts style that would fit in the cowl of my plane and yet clear the carburetor is what I have in mind.

RE: OS Rotary engine
 

As long as any muffler isn't going to restrict the engine to the point it overheats, there's no problem. Depending upon the size of the chamber and size of the exhaust outlet(s), noise may be a factor, though.

RE: OS Rotary engine
 

Thanks for the help. The one I have in mind should be fine, probably no more back pressure then the one that came with the engine.

SteveC