I have heard that you need to bump compression in order to maintain idle quality with hotter cams. My question is, why? How is it that a higher compression ratio will smooth out idle with hot cams? Jus' wonderin'....

 

I don't believe that is true but it may have happened to a couple of people because of their situation. Say if you had a tired motor which you rebuilt with higher c/r and new rings, actually the sealing of the new rings gave it a smoother idle.

 

Interesting...yeah, I'd wondered how that worked...thanks!