Counter Rotating Engine

[flynwest]

For all the engine guru's can an O 360 counter rotating engine be made to run the right way. Plan on using Light speed ignition and a Cold air sump anyway Probally need a new cam too. Walt? Mel? Rocket Bob? anybody know?

[Mike S]

Oil pump may be an issue, and if the accessory case has helical cut gears, there may be an issue with thrust washers. Magneto points??? Or, entire magneto??

Prop governor??

All speculation here, never been inside a Lyc.

And of course as you already mentioned the cam.

[DaleB]

I have wondered, given the seeming ready availability of fairly cheap left-hand engines, whether just putting on a left-hand prop would be a practical approach. I'm not sure I'd actually want to own & fly something THAT oddball, but it has me wondering.

[N941WR]

You would also need a custom engine mount, if you did this.

Originally Posted by DaleB

I have wondered, given the seeming ready availability of fairly cheap left-hand engines, whether just putting on a left-hand prop would be a practical approach. I'm not sure I'd actually want to own & fly something THAT oddball, but it has me wondering.

[rocketbob]

No the crank journals are phased backwards but why not keep it as-is and just accept that you will have to use left-rudder. No big deal to adapt to as I'm sure any Russian pilot already knows. Probably could find a left turning prop for cheap.

I suppose the engine offset in the mount would be in the wrong direction if Van's still does that.

[Snowflake]

You'd need a custom cowling, too... I think the center hole at the front is offset slightly to match the offset mount.

[tim2542]

I have a friend that went with a LH engine. The savings evaporated and more when he had to buy a crank and cam. He tells me the LH specific parts are double that of a RH
Tim

[Bob Kuykendall]

Originally Posted by Snowflake

You'd need a custom cowling, too... I think the center hole at the front is offset slightly to match the offset mount.

On the RV-8 at least, the engine mount is arranged so that the crank axis points about 2 degrees to the right of the aircraft's longitudinal axis. The crankshaft flange is right about on the plane of symmetry. The cowling seems to be molded to conceal to the degree practical the asymmetry of the engine installation. I think that if you look down on the front of the cowling both the propeller hole and the air inlets are offset slightly to make the whole thing look as symmetrical as possible.

To use an LH-rotation engine, you'd pretty much have to make a new engine mount, otherwise the turning tendency of the P-factor plus the crank axis offset would make both climb and cruise require a miserable amount of left rudder. Then you'd have to modify the cowling to accommodate the reversed offset. That's in addition to a left-hand prop and all sorts of other stuff.

If I already had one of those engines, I'd look into horse-trading it for a right-hander so that a light twin driver can get a few more years out of their airframe.

Thanks, Bob K.

[DaleB]

Yeah, I'd forgotten about the engine mount. Even in R/C models we'd shim the engine mount or drill the holes to provide a little offset.

[flynwest]

Thanks for the posts guys. I now wonder if the cases are the same. Maybe a new cam and a stroker crank. Hmmmm