hey im having to replace my engine mount in my T.H. voyager what size hex head or screw can i use for mounting a os 46la i do not have my manual on the engine, and before it was held on with a metal bar over the engine holes im going to drill and tap these in thanks also it is a great planes engine mount.

The most common screw used to mount .40 engines to engine mounts is called a socket head cap screw. Size 6-32 is good for this size engine. It is a machine screw (not a wood screw or sheet metal screw). The head is designed to be screwed in with an allen wrench. You drill the holes through the mount so that the screws are just tight. The screws can cut their own threads through the plastic mount or you can tap the holes with a 6-32 tap. Or you can drill the holes even larger and put a nut on the back side. Use a locking nut - the kind with a plastic ring embedded in the nut that keeps it from vibrating off.

I basically do the same as DMcQuinn.
I use the 4-40 hex screws and locking nuts.
I like these screws for several reasons.
The hex nuts do not strip as easy and they are machine thread.
Also I like the locking nuts, they stay on.

Good Luck

Bill

thanks for the help i went with the 4-40 bolts with washer and lock washer seems to work alot better than nwhat the arf had from the factory thanks a lot mike

No problem Mike.
Is this a second plane?

How does that engine mount, upsidedown?
I was just looking at the picture on Tower.

Bill

Is this the plane?

bill,

Yes that is the plane the engine mounted inverted is not bad, the carb is a little lower than the fuel tank so you have to keep the throttle closed when fuel is in the tank, i really enjoy the plane i have a os 46 la on it and it fly pretty fast. well hoped this helped you out . If you get one change the pushrods for the nose gear and throttle they are to weak, and also change the engine mount i went with the great planes glass filled mount, this arf is only 89.99 not bad and again it flys great. thanks again for the help mike