Jerry Hey wrote:
I weighed the completed Tailwind engine mount today. Every thing,
including Barry Isolators and bolts, etc was 25lbs 14.5 Oz. This
includes 8.5 lbs for the gear mount. Without the gear mount, a good
firewall forward figure for most applications would be around 17 lbs.
Not bad when you consider that the PSRU adaptor plate is included.
Jerry
Tracy's original mount with out the PSRU adapter plate was 28 pounds.
I don't think that included the 3/16" thick 4130 steel plate between
engine
and oil pan. With out holes or ears (13" x 18") that would weigh about
13 pounds on its own.
The Tailwind and Tracy's RV4 have similar gear mounts.
Paul Lamar
The RV-4 mount does indeed weigh almost 28 pounds but that includes the
4130 steel plate. This also includes the main landing gear mounts. Could
have saved about 3 pounds by using an aluminum plate instead of the 4130.
My 20B mount weighs a total of 14 pounds after I cut most of the center out
of the 1/2" aluminum plate between engine & oil pan. I used a carbide blade
in a worm drive Skillsaw to do this instead of machining out a pocket. A
thin sheet of aluminum forms the oil-air separator plate.
The RD-1A/B adapter plate weighs 7 1/2 pounds without any lightening done.
I cut 1.75 pounds off the one on the RV-4 just using a band saw.
Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com
To have a fair comparison with what Jerry is doing you would have to add the
7.5 pound adapter plate for a total 21.5 pound less the main landing gear
as the RV8 you are putting the 20B in has a different.. separate landing
gear arrangement which weighs a whole bunch more :)
Jerry wins hand down at only 17 pounds with comparable configurations! :)
Have you checked the deflection of that adapter plate with a 600 foot pound
prop gyro torque after you cut off 1.75 pounds? :)
Paul Lamar
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