Intake valves hit pistons

[madmaxx]

132lb seat pressue with that profile, what is open pressure?. If you have less than 400lbs do what you like but I would not set the preload past 1/4 turn on the rocker adjustment. Unless you are using beehive springs and titanium retainers YOU WILL FLOAT THE VALVES ABOVE 5500 RPM'S. You could set the lash to zero but then you will just hammer your cam to pieces and not know it until extensive damage is done. I agree heavy spring pressure wear components, better wear than hammering when the lifter leaves the lobe and smashes down onto the back side. The real solution is a reasonable cam and spring pressures, if you want more power there is no replacement for displacement. Get a larger engine.

Originally Posted by CobraV8

I know that mentioned gentlemen have an excellent reputation, but I already gathered all the parts over the last months, and I live on the other side of the pond so everything is a little more complicated (shipping etc).
I bought only brand name parts from well known companies however (Comp Cams and Lunati), so I hope to be on the safe side.

The springs recommended by Comp are 132lbs seated. I know these are a bit on the soft side for the camshaft, but heavier springs also tend to cause problems like collapsing the lifters and raised stress levels for all valve train parts. If the solution was that simple, the stiffest spring available would just be used for every application.

One thing I don't understand is why so called "rev kits" aren't used more widely on these engines. These very simple and cheap devices place springs on the lifters, effectively eliminating the inertia caused by the lifter's weight.

People spend lots of money for titanium retainers, beehive springs and ultra-light rockers in order to lighten the valve train. The use of a rev kit to cancel out the lifters weight seems uncommon however. Some are available for Chevys, however I only found one for Fords made by Price Motorsports, and this one is available only for 9.5" deck height blocks.

For hydraulic roller cams with link bar retrofit lifters such a kit would be very beneficial, as these lifters are really heavy.

Maybe I'll fab up my own rev kit, I'll do some calculations for the springs required for my lifter's weights.