I am looking at possible kits I am thinking of getting and I would like an engine that would work with all of them. Would the OS 91 be to big, powerful, heavy for the Top Flite spit. I would like that engine for the TF Cessna 182, and possibly the F4U.

Where you talking 4 stroke or 2 stroke? You could use either engine in all these.

The four stroke would do well in the 182. The OS 91 Surpass I & II are sweet hearts and will work in your war birds but... Cowling is always simpler with the 4 stroke.

The case of the 2 stroke: The 2 stroke 91's seem to be more used it the war birds. In any scale application they require some different exhaust system than stock.

Not to say that the OS 91 FX is not a good engine but some of them give people fits. Others run perfect. There's one at the field that has always run perfect with never any problem but it's a couple years old. If you do use the OS, then put a different needle valve assembly on it.

The Super Tiger 90 seems more stable right now. That's what most every one's using at the fields I go to.

The Magnum XLS 91 2 stroke is relatively new and has good reports on it.

Enjoy.

I pictured the 4 stroke .91 in my mind. Probably because there's a friend of mine w/ one in a TF Cessna, and another w/ one in the TF Corsair. Great combination, and would be real nice in the Spit too...

The OS .91 four stroke would work fine for the TF Spit, provided that you build the Spit light. This engine is not too big, powerful, or heavy for that plane. In fact, chances are you will need to add nose weight. This engine will also work fine for the F4U. I have the pumped .91 Surpass II, and it's a sweet running engine with plenty of power.

With the 0S 91 surpass would you have to mount it upside down or on the side?

I was thinking about the 4 stroke but now that you brought up to 2 stroke OS 91 FX would that be to much for the spit.

It is best to mount the 91 Surpass upside down since it will look cleaner. Otherwise, half of the cylinder will be sticking out the side. Do not use the .91 two stroke in the Spit because it will make the plane look and sound like crap.