Are 1.6 ratio roller rockers OK with "press in" studs? What is the cut-off for press in studs to be replaced with screw in studs? Any info will help out. http://www.camaros.net/forum/smile.gif

Depends on your valve lift and RPM. If you keep it under 5500 you'll probably be OK with 1.6 ratios and press-in studs. You also have to check your head clearance 'cause most factory heads will interfere with the pushrods unless modded with Competition Cams' "Louis Tool".

I wondered the same thing. I have press in studs with a Performer RPM cam and 1.6 rockers. No problems so far, but I am keeping an eye on it.

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Mark

1992 Firebird 355/Six Speed (Soon to be LT1)
1991 RS 350 / 700-R4
1987 Toyota Pickup 383 / 500 + HP 10.963 @ 119.95 Slicks / 11.997 @ 114.23 Radials
"Speed KILLS, so drive a FORD and live forever!"
http://personal.lig.bellsouth.net/~racer383/

I would think it has more to do with the stiffness of the spring rather than the amount of lift. If you put a monster valve spring on there, you are going to pull the press-in stud out before you ever hit full lift.

Kevin, thank you for anwering another question that I had and that was the Louis tool. You must have been reading my mind! Gheatly, that makes sense to me also. I wonder at this point then, what seat pressure is too much for press in studs?

I would call one of the cam companies. I would go with screw in studs if you even think you are going to have a problem. Look at it as cheap insurance.

One other rule comes into play when changing rocker arm ratios: The rocker arm ratio times the pounds-per-inch of valve spring open pressure equals the net load being applied against the cam. It is possible to overload the cam lobe by indiscriminately changing the rocker arm ratio. If the resulting valve spring open pressure exceeds the recommendations of the cam grinder, severe lobe wear can occur. Not so much a problem with stock pressure springs, but comes into effect with aftermarket higher pressure springs.

One other interesting thing is that solid lifter cams valve springs are usually stouter then hydraulic lifter cam springs are.

I think it's because solid cams are ground with more aggressive ramps (and higher lifts) so can whack the lifter harder to start the valve opening, etc..FYI. pdq67