A little help needed.

I had a call today to look at an engine tomorrow, the fellow said he thought it was off a walk behind tiller, well that didn't peak my interest too much until he said it only has one valve and the other is what he called a "pop valve" ok now I'm curious but then he really messed me up when he said the cam was a "four to one ratio"(his words) the only thing I could think of was an Aermotor 8 cycle (I have one) so I quizzed him and it's not an aermotor. Maybe it's not anything different and I just don't understand his terminology. He said there were no names or anything on it to identify it. Any ideas as to what the heck I'm going to look at? Thanks all and thanks Harry!!!

Newbie Nate

Its air cooled (fins) no hopper.

Could be a Briggs Model PB

I agree with Bill. Sounds like a Briggs PB. I believe the cam in a PB runs at an 8:1 ratio and has four lobes on it for the exhaust valve. The intake valve is atmospheric. Been a while since I had one apart though.

Mike

sounds like a early torro engine to me .the early torro engines had the drive taken off the cam shaft instead of the crankshaft.i had 2 of them 1 had a 6 to 1 ratio,i took it apart the cam had 3 lobes on it 120 degrees apart 6-1 ratio.my guess if they made a 8-1 ratio if you tore it down it would most likley have 4 lobes on the cam shaft.has anyone taken apart a early torro engine.i don,t know how to post pictures.i did take pictures of the 6-1 ratio torro camshaft because when you tell people about a single cylinder engine with 3 cam lobes they think your'e kidding them-chuck

sounds like a early air cooled torro engine to me

The A.O. Smith Motor Wheel has a 4 lobe cam. This later became the Briggs and Stratton model PB if memory serves me right.