max rpm with flathead?

[bassandgokarts]

i have a 5hp flathead but the block has bushings machined for the crank which im skeptical about. how would i put bearings in if thats even possible for this block. just building a mild engine nothing too crazy.

 

[Joe-405]

You can get around 13-16 hp with a standard block before needing the dual bearing blocks.

 

[bassandgokarts]

thanks was worried it would wear right out, whats the best way to increase my compression ratio? deck the head and thinner head gasket?

 

[Hellion]

Yes.