Any major issues that the Briggs OHV engines are proned to have? I have the chance to pick one up, but I am not too familar with them in a race mower.

I have heard of replacing the stock valve train assem. with an upgrade to keep the engines from going up in smoke (fans like to see this, drivers not so much). Anything else?

I think with any engine it really depends on how it will be used. Both the Flathead and the OHV have their own issues depending on use. If using the OHV for racing it would depend on what size engine (model number, type, manufact)and RPM range you would be running it at.

This also brings in to question if you are going to race it at what class and what club rules would you be following based on that class? Different classes require you to be governed to a specific RPM range. I guess what I am trying to say is if running a stock engine (crank, rods, piston, valves etc) in a lower class I would probably go with the flat head, if running in a class with unlimited RPM and you have money to upgrade engine internals I would go with the OHV.

It all comes down to how fast do you want to go, need to go, and can go based on your class. Then how much money do you want to spend.

Remember Lawn Mower racing is for the sport of it, no big purses to win. If you can run with the pack and have fun while doing it without spending big $$$$ thats where you want to be.

Hope that helps you in your decision, probably more info than you wanted.

Never too much info. I will have to do some more research now that I know what you know! Thanks for the quick reply.