Bill:

When you say "plain bearing"--are we talking about a bronze bushing on the crankshaft??

I'm talking about a Bronze bushing engine. Like an LA or FP series engine.

They have a lot of end play in the crank. But--when used in a standard tractor setup--the prop force pulls the crank forward enough to keep it seated against the case bushing.

I've been told that when used as a pusher--the loads from pushing on the crank will force the rod pin into the backplate and make lots of shavings and other nasty stuff inside the engine as the rod pin wears a hole in the backplate.

This doesn't happen to a ball bearing engine because the crank is seated in the bearings and crankshaft end play is very minimal.

I always use Omega fuel. Usually 5% for break-in and then 10% for sport flying. I'm pretty sure that the Omega fuels are 30/70 blend with total oil content at 17%. Will this work for my pusher engine? I'm not opposed to adding a bit more castor to the fuel. If you REALLY think I should add oil--how much would you reccomend per gallon?

Thanks for the help.