Hydro pre-load

[timos]

Hallo,

Is there a difference between the stock cam and the CompCams 68-232-4 diameter? Because I have now a Hydro pre-load of 0.1” and it should be between 0.03” and 0.05”.

I have nothing changed on the valves and use new Crane Hydraulic Lifters 99278-12.

Unfortunately I don’t have the stock cam and Hydros anymore for measuring.

THX for answers.

[SilverXJ]

Cams will have different base circles as well as lifters (they aren't called "hydros") having different dimensions. Expect a cam with more lift to have a smaller base circle. Also, any change to the block deck and head surface will change preload as well. Valve jobs can also change preload.

[timos]

Thanks,

I thought the CompCams 68-232-4 and the Crane Hydraulic Lifters 99278-12 are a direct bolt in replacement.

Does anybody know the base cycle difference of the CompCams 68-232-4 and stock cam as well as the difference of the Crane Hydraulic Lifters 99278-12 and stock lifters? I only want to make sure, that the excessive pre-load of 0,1” caused from nothing else.