Thanks for everybodys Help and advice my first Flathead build is done and running

[Russco]

Originally Posted by 19Fordy

Congratulations on building a nice flatty. What are "Fire-Slots"?

Its a valley machined into the head chamber for flame travel across the top of the chamber I dont know if it works or not they were already done like that. I have seen racing Briggs & Stratton heads done like this for Go kart racing engines.

[JWL]

With used rods .035 is about minimum for most engines except at higher speeds. With new rods, a little more. When I am asked I usually say .050 because most non-professional builders can't or don't measure clearance EVERYWHERE on the dome. I just want them to be safe and happy. The performance difference is minimal.