Mailing List flyrotary@lancaironline.net Message #64702
From: Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net>
Subject: Engine mount "rubbers"
Date: Tue, 12 Mar 2019 10:28:22 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>

After a lot of back and forth over the last week I decided to use four Barry mounts for my Renesis installation in the RV-4. Two at bottom rear of engine, two at top front near re-drive attachment (actually the top mounts near firewall).

I estimate total engine installation with re-drive, prop, radiators, oil cooler, exhaust, intake and alternator  to come to about 330 pounds or less.

http://www.barrycontrols.com/UserFiles/File/Product_Catalog/bonded_tube/bcdi_prod_bonded_22000_series.pdf

Choice is between Barry 22001-15 (or -14) and 22002-13 (to -15) or their equivalent.

-13 appears to be a dyrometer (stiffness) of about 55, -14 about 65 and -15 about 75.

Brian Trubee used the 22002-13 equivalent.

I guess the 22001-14 or -15 can handle the load (rated at 250 to 300 pounds, showing compression curves to 1,200 and 1,800 pounds, compressing 0.15").

The 22002-13 to -15 rated at 240 to 630 pounds, showing compression curves to 1,000 through 2,600 pounds, compressing 0.25"

Obviously the softer ones will allow a lot more motion, perhaps too much at the spinner/cowling intersection?

Other than the 22002-15, they are available for less than $30 for four, including shipping (not including bolts, washers and mount plates).

Any opinions or suggestions as to which to use?

I also need to figure out the optimum angle of the mount plates (OSB wood in pictures). Looks like CG will be mid front (closest to prop) rotor housing.

Finn


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