What can I use to mount the engine on, could I use wood screws or not.. its on an great planes plastic mount, I dont have any bolts right now and I want to do somthing productive on my extra 300 tonight...

They should have provided 4 sheet metal screws for that

i use bolts and locknuts... takes an act of God to remove them...

edit:
sheetmetal screws to mount an engine?? man... you got guts...

I agree with Balsa Master. bolts and locknuts are the only way to go. You can find them at either you LHS or a neighborhood hardware store.

Drill and tap the engine mount. Use long enough machine screws to add nylon lock nuts. If that engine ever gets loose on the mount you'll think the world is ending. Can't be too well mounted even on shock absorbing mounts.

its amazing how many kits now just use self tapping screwa to mount the engine,

one hard landing and away she'll go, id do what the others have said and bolt it in............

I have just drilled and tapped the glass mounts. Never had loosening problems. A drop of thin Ca also helps on the threads.

Mark Shuman

I've always used sheetmetal screws on the plastic mounts. Never had one break or loosen. The screws are stronger than the plastic.

I have always used sheet metal screws on nylon mounts. I do like the socket head variety. The key is to drill the correct size pilot hole. Too small a pilot hole and you may snap off the screw head or split the mount; too large a pilot hole and the screw can back out. A little oil on the screw helps it go in the first time.

I don't like using sheet metal screws or tapping an engine mount. I use machine screws with nylon nuts and lock washers.
A running engine has some vibration to it which will loosen up screws. One of the reasons why I'm not a fan of arfs that use blind nuts
in the firewall to fasten the engine mount.

Dave...

Don't use the sheet metal screws. Often they twist in half when you take them back out and then you need to buy a new mount. Use socket head, stainless steel bolts and tap the mount except the last 1/4" that the bolts go into. That turns the mount into a lock nut.

Engine Mounts

I'm with Ed--nylon mount, socket head sheet metal screws, eased in with a drop of oil. Engines do vibrate for sure, but if I torque down a SHSM screw with an L-wrench finger-tight, they stay tight indefinitely. Use the largest size screw that will slip through the engine mount lugs--#6 for smaller engines, #8 for medium size, #10 for larger sizes. Pilot hole in the nylon mount should be just a bit smaller in diameter than the OD of the screw threads, then you will not have screw heads breaking off... 1/8" bit for #6 size screw. Steel threads in nylon mounts hold very well, no vibration problem, no stripping out. Use a length of screw that reaches all the way through the thickness of the beam.

Nylon locknuts on machine screws hold well, but you need access to both ends to mount or remove the engine, whereas SHSM screws all you need is access to the screwhead.

On occasions where I've had to use aluminum mounts, I like to drill & tap the beams, then fasten with socket head machine screws and split lockwashers. Normally I use an aluminum mount only where I need extra noseweight. It does take some care to position the mounting holes precisely. If you screw up, you can often salvage the situation by drilling out the tapped holes and going to machine screws with nylon locknuts on the other end as a last resort. Measure carefully, mark precisely, punch the mark with a steel punch to keep the drill bit on center, steady the mount with a drill-press vise, and definitely use a drill press rather than hand drill. (Nylon mount is so much simpler. And lighter. And cheaper.)

Caffen Man's above post is dead on (as usual0. I forgot that one. That method is nearly foolproof and simple.

Mark Shuman