Can anyone give me a ball park figure as to gains one can expect from a P&P? It's on a b16 head that's going back on a b16 block.

Also what is the rule of thumb for retarded cam timing when milling the head? Is it one degree for every 10 thousandths?

 

A P&P job isn't gonna net you that much on a stock B16 head. Maybe a 5hp in the upper RPMs. B16 head are already one of the best flowing heads Honda has, next to the "R" heads. The "R" head are nothing more than a factory ported B16 head anyways .....

If you're adding some bigger cams or perhaps some FI(Forced Induction) then the port job will amplify any of those mods. But as far as being able to tell a difference if that's all you're doing I wouldn't hold my breath.

Also, I wouldn't mill the head, if you're looking to up your compression, swap in some pistons to do that. Or at least a thinner head gasket. Milling your head is not revesable. That's just a personal peev on my part though.

 

With other mods like cams, an intake manifold, etc; you can see gains of up to 10 hp at the top of the rev band. Just remember that's on a reasonably built up motor.

 

I'm milling the head cuz it's off, and I'm too poor for pistons . I was gonna P&P while it was off too, but since I guess I won't see any big gains with just boltons I guess I won't bother.