rssteiny

instaling valve springs in my hp500s got the new crane springs they call for 150lbs at 1.900 there going in at 1.850 or so that will give me more seat pressure anybody done this with a hp500 having more than 150lbs seat pressure on a all stock hp500 whats your thoughts.

thanks in advance

rmbuilder

rssteiny,
The Crane spring for the HP 500 is part#99896.
It calls for
132#@1.906 (closed)
414#@1.306 (over the nose)
Bind 1.085
Rate 470#/in

That would give you a value of:
158#@1.850 (closed)
440#@1.250 (over the nose)
You could use +.050 locks to get your installed height to 1.900. I would put them on the Rimac first and see how close they are.
Bob

formula31

Exactly what rmbuilder said. Use the +.050 locks after you confirm the spring pressure. Dont cut corners here. Its the weakest part of these engines. Excess pressure will cause the roller lifters to fail.

cstraub69@comcast

I wouldn't recommend that much pressure on an OEM lifter, especially if it has time on it. You need to be about 140# to 150# on the seat. You get to much seat pressure and she will collapse the plunnger assembly in the lifter.

Chris