5hp flat head rpm

[acg23]

what rpm does this engine idle at. also what is the highest it will go with and without a governor. thanks

 

[solomon]

idle can get really low. MAX RPM without gov is about 5500, thats valve float. Rod can go out at 5000

3600RPM with governor

 

[acg23]

alright thanks, i do not knw much on engines so what do you mean by " thats valve float"

 

[freakboy]

the valve springs are to weak to push the valves down at that high of rpm so they dont close all the way and basicaly you cant go any higher rpm without upgraded springs.

 

[newrider3]

Valve float DOES NOT MATTER on a flathead. In out application, the worst that will happen is it will knock the carbon loose from the head. Most racing cams for flatheads are actually designed to float the valve (thus providing more lift on a cam that still passes tech for maximum lift).

Now if you're running an ohv, valve float is a different story.