When in the build to mount the engine

[pfhoeycfi]

There is a good article in the March 2020 AOPA mag by Mike Busch discussing installing cylinders etc on engines while on the mount. Granted its directed toward lycoming engines but its worth a read.

peter

[Onex107]

I built mine suspended between two saw horses so I could rotate it for mounting the cylinders on each side. A piece of plywood clamped to the rear case gives it a foot to stand on. It's much easier to install the push rods, pushrod tubes and cylinder heads if they are vertical. To install I screwed two eye bolts in the ceiling of my garage and hung the engine with two adjustable tie down straps, rolled the three wheeled Onex up to the engine and slid it on. It would be just as easy to remove it and let it hang multiple times, while you work on the fire wall.

[Spaceman]

If you use the plans prescribed bolts, the nuts will probably bottom on the bolt shank before the bushings compress. Because the bolt will turn with little effort after the nut bottoms, it can give the impression of a "snug" fit. Look for a widening gap between the mounting plate and the bushings in the top aft and bottom front areas after the engine hangs for a couple of days.

You could remove a bolt and screw the nut on till it stops, then measure the distance (count the threads) from the end of the bolt to the nut to determine if the nut has come to the end of it's rope when installed on the plane.

Be sure to let the engine rest on the mount for a while before fitting the cowl. If you fit the cowl when the bushings are fresh, the engine will sag and you'll wonder where you went wrong.

I'm sure urethane bushings would cure most of the sag that we get with the rubber units, but I haven't found any that are dimensionally correct yet. The hole size of the mounting plate is 1", and all I can find is a step-down to 7/8". If I was rich, instead of so darned good looking, I'd have custom bushings made.

Good tips! I'll have to investigate the bolt lengths. I think you can machine urethane pretty easily; it probably would be pretty doable to make new bearings on a lathe... I have the same problem and I'm not even that good looking!

To install I screwed two eye bolts in the ceiling of my garage and hung the engine with two adjustable tie down straps, rolled the three wheeled Onex up to the engine and slid it on. It would be just as easy to remove it and let it hang multiple times, while you work on the fire wall.

That's a good idea; I've lifted up motorcycles that way. I managed to do it with the engine just sitting on a folding table, but I think a rolling cart would have worked even better to be able to move the engine aft onto the mounts once it's all lined up. Or if you're doing a tri-gear I guess you can roll the plane forward a little at a time.