New member here! I am looking for the dimensions of the metal conical mount that is cast into some Lycoming engines. It looks like an inverted hour glass, with 2 back-to-back cups, ready to accept 2 rubber cones. I think it has a 1" through hole and a 30° cone...I think. Anyone know what the flat-to-flat thickness of the mount is? Or any other dimensions?

I am making custom motor mounts, and I ordered the rubber cones (I got the softer ones from aircraft spruce) but I can't find what the dimensions of the receiver should be to accept them.

For background I am in the middle of a resto-mod of a 1956 Cessna 172. I am converting it to experimental and am building up the engine now.

No idea but getting a line of mounts made for the experimental market would be a very popular move.

I have a O-320 sitting in my hangar I could examine for you.

Curious about the economics of this though. Just looked on Spruce...$16.50 per rubber for the O-320/360, the approved Lycoming part. Have to buy 8 of them for a grand total of $132.00. They also offer a "homebuilder's pack" for $55, but not approved for certified aircraft.

Are you proposing 3D printing with some kind of elastomeric filament? Doesn't seem like it would pencil out unless the main objective is to achieve a firmer bushing.

My bad, I was thinking Dynofocal and the Lord mounts. An experimental alternative to those would be awesome.

I just measured an O320-B2C that i have in my shop.

The machining looks like it has been sanded to take all of the
sharp machined edges off, so it is hard to get accurate dimensions with a caliper, but this is what I got. Im guessing that was to avoid damaging the rubber. Looks like this on all four holes from two engines (both low time first run)