Take a tecumseh 3hp engine block and a Tecumseh 5hp engine block to another part of the earth and ask them to cut it out of billet would probably cost less then one American $100 bill… Whatever that would equal out to in there currency.The valves are too shrouded, too small and 2 too many. It has been proven that any more than 4 valves per cylinder hurts flow.
That is so cool! When I was a kid I could run mine for hours without getting bored. The school by my house even had a gas powered car club.These are so cool.