Longwinglover
Registered User
Charlotte, NC
John Melnick said:The other Cub with the C-85 has wooden spars and a tapered crank - both of which are ok but are real problems if things do not work out as you hope they should.
Mr. Melnick,
I'm not sure I understand this last statement? The taper shaft will fit any propeller you could use on the engine, you just have to use the hub. If you switch between two props and you have two hubs, the time to swap props is less than for a flanged crank.
I realize that you are up in CN and I'm not sure if you have the option, but down here, if you had to overhaul the C85, you could, by STC, install the O-200 crankshaft. You'd get (potentially) more hp and your flanged crank.
I'm not sure why people shy away from wood spars. There is no difference in strength (or aircraft GW) vs. metal spars. All parts are available new (as with the metal spars). So what is the problem?
Per the type certificate both the C85 AND the C90 are limited to 80hp continuous. They can respectively produce 85 and 90 hp on takeoff (if you can turn them up to the RPM limit), but probably the real difference is in the (more) torque available in the C90. You MAY be able to swing a longer prop with the C90, but no longer props (except wood, which I don't think you will use on floats) are approved on the TC.
Down here, I'd say that the C85/O-200 crank engine is the optimum engine for a certified J3.
Good luck with your search!
John Scott