What is the best way to find the sweet spot before bolting on the engine on the engine mount....?

I think i saw some stuff for that on tower hobby....


can u guys help me out on this?

You put the engine on as per specs.

You ( Normally, but with a few exceptions ) DO NOT move the engine from the recommended.

Most planes either come pre-drilled or have a sort of cross hair on the firewall which represents where the center of the BASE of the mount is supposed to go.

Most mounts and engines come with guide lines that help you get everything lined up.

What Tower sells is a C.G. tool and a "hole locator".

The hole locator is used to find where to DRILL on the mount with the engine at the specified location.

All you do with it is scribe a mark where you will subsequently drill.

This is a bit harder than it looks because the engine gets in the way, and othersie you would tend to offset the hole too much if you used, say a pen, or a drill bit.

The C.G. tool is used to adjust the weight of the components in the plane to get the plane to balance at the recommended location.

It's not the other way around.

Once you've flown the plane as per spec you can adjust the C.G. to your liking, but the engine tends to stay put.

I use the [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXK378&P=FR]Great Planes Dead Center Hole Locator[/link].

You can't miss with the Dead Center hole locator. I would highly recomend it. Good Luck, Dave

The GP hole locator is a great tool.

Remember that it does not show you where to mount the engine though as implied in the original post.

Use the specs for that.

The hole locator is a great tool. But there is a simpler method I saw on the internet.

Set your engine on the mount upside-down, then measure and drill your holes using the hole locator. Engine stays where you want it until all the holes are done.

Tiger - depending on the engine and the mount, it can't always be placed inverted in the mount. Also if the mount is in a tight position there may not be room for the engine cylinder inverted either.

Tigerdude,
If you are having to postition the engine in a plane where it has to be placed in a certain postion (for instance, inside of a cowl) it's usually impossible to do as you mentioned. You need to work with it upright to ensure you have it in the correct position.

Ken

I have never done it myself, just wanted to share a tip I saw. I have no evidence that it really works, and no photos were shown how its done.