Hi, I was wondering if anyone could tell me what this engine is.

I wouldn't bet more than a nickel on this. but it looks like a VERY, VERY old Q-35. In fact it looks like its been cut out of a saw. The orginal Q-35 were from a Petco Chain Saw.

Nice call TKG.
A person that gave me this said he thought it was from a MAC saw.He couldnt remember.I recieved it the way it is in the pic.
It was sold as a 40cc but it is really a [37.6]actual.
The actual case is only 1 inch thick and 1-3/4 inches in diameter so its shaped like a DA case.Im going to shave a lot of metal off of this here shortly,this weekend to see how light i can get it and take it apart to inspect the bearings,and see if theres thrust washers in it.It has at least a 1/32 of free play[end play].
As in the pic with the flywheel on it it only weighs 2-3/4 lbs.[46 ozs-sounds better].
The fins are off to one side more so im going flatten them a little to match the other side.
It is a short shaft engine and the crank is around 1/2 inch in diameter.
Mines a single ring.Good compression with the points.
If your interested in a low priced parts engine PM .Itll save me from doing any work to it.

You lose...Definitely NOT a Quadra...No small Quadra had a case like that or a carb boss like that...A VERY old Q35 had the spark plug facing forward at 90 degrees to the cylinder...Petco was the in between company after Klaus and before US Engines...Petco is Plastic Engine Technology...
Trail Mfg was the very old Quadra chainsaw company...ALL old Quadras have a crankcase like a G38...

This is a very old Quadra

Well it was only a nickel

It is a Remington Chain saw engine. Bennet used to sell parts for the conversion. 38-40cc size. I believe he still lists mufflers for it. Joe