Obviously the word is out not to put in an offset.  Just to add to the fray
I wanted to mention how difficult it was to make my cowl fit with an
opposite direction offset than the right offset it was shaped around.

Left offset (like me....  bad idea!)  neutral or stock is obviously best.

Dave Leonard

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On
Behalf Of kenpowell@comcast.net
Sent: Sunday, May 23, 2004 8:14 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] engine mount geometry


I built my RV-4 mount with no offset.  I actually built inserts for the
eshaft bearings with a hole in the middle so I could 'sight' thru the engine
(no eshaft in the engine mockup) to the thrust line (an 'X' on the mockup
firewall).  I built it with no offset because at that time I didn't know
whether Tracy was going to build the 2.85 drive and I absolutely would not
fly with a Ross (Bill Freeman said the Ross was dangerous-good enough for
me; too bad Paul L. ran him off and he didn't choose to participate here!).
Thanks for the info that Tracy's mount is also built with zero offset - I'm
in good company.  I had planned on vertical stabilizer offset based on the
redrive I ended up with - I hope someone knows the aero of motormount offset
vs. vertical stab offset.  I would shim the motormount a small amount in
order to reduce the vertical stab offset if the aero would benefit.  My RV-4
plans build .25" offset in the conical mount.

Ken Powell