RV Engine Mounts

[LifeofReiley]

I was wondering the degree offset for the Van's engine mounts? Are they all the same? Also, what is or should be the degree or angle of the crankshaft (horizonal) say the prop extension measured with an angle finder in relation to level flight? (I believe Van's states the longerons are level in level flight mode)... Russ, are you out there?

[Russ McCutcheon]

Hi D,

As it applies to engine mounts, we only build the RV-4 mounts and I don?t even know the answer for that one, I started working for Lee 20 years ago, 1991, he built the engine mount jig in about 1982, we did make some changes to the jig in the early 90s to accommodate the new long gear legs but otherwise I have never had a need to know the answer to your question, we still use the same jig to this day. You better look up an old set of -4 or -6 planes I bet it?s on there.

Russ

[LifeofReiley]

looks like I need to pitch this one straight to Van's...

[LifeofReiley]

info came back from Van's engineering today.

Answer: Engine Mounts are set-up 1.25 degrees offset to the right (horizonal) and 0 degrees offset in the up or down (vertical) level flight.

I took the 'ole smart level to the vertical offset (crankshaft flange) and referenced it to the longerons (level flight reference neutral) and sure enough dead on 0 degrees.

Next, to fly the plane with the smart level inside the cockpit, level flight and record this info.

[Russ McCutcheon]

Just curious. To what end?

[LifeofReiley]

Originally Posted by Russ McCutcheon

Just curious. To what end?

Just playing with Speeds and Mods, Props and a few other things.

[Russ McCutcheon]

Sounds fun!