What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Engine mount/cowl fitting

scottmillhouse

Well Known Member
I'm doing the finish kit on my 7 and have been planning on fitting the cowl with surrogate run-out engine parts, a crankcase, crankshaft, bearings and a spacer to center and position the rear bulkhead for the spinner. I plan to ballast the assembly to match the complete engine weight for sag. In mounting the assembly I find that I do not have the same amount of bolt end showing left to right at the engine end. Obviously the crankcase is machined differently left to right. This got me wondering if there would be slight differences over the years that may make each installation unique. Anyone have experience with using a surrogate or replacing an engine with the cowl fitting or requiring modifications?
 
Is it a dynafocal mount?
Was it a conical mount changed to a dynafocal?
Are the ears the same thickness, machined incorrectly?
Are your rubber mounts seated correctly in the engine mount and each other?
 
Is it a dynafocal mount?
Was it a conical mount changed to a dynafocal?
Are the ears the same thickness, machined incorrectly?
Are your rubber mounts seated correctly in the engine mount and each other?

standard dynafocal, new mounts properly seated and torqued, ears appear machined correctly from factory and not converted. Crankcase is runout so it has 1000s of hours. I assume the front crankcase machined bed for the nut that is countersunk in the crankcase is variable in thickness and causing the different lengths. Just the difference of several washers across the bolts. It causes no problem except I am concerned that over the years there could be slight changes that could make cowl alignment inconsistant. Looking for experience from other builders on installation of different engines into an airframe on cowl alignment.
 
Back
Top