Legitimate question, I am curious to what guys are running for spring pressures, on their big block marine hydraulic roller engines, and how many rpm you turn?

I have catalogs from crane, comp, lunati, crower, isky, elgin, howards, etc. When looking thru their books, most give a spring part number, to go with the cam. Across the board, it seems pretty common, to see a spring setup that comes in around 150ish closed, and 400-450 open pressure for a bbc hyd roller.

For example, the every so popular crane "741" and "651" cams, are spec'd with a crane 99896 spring.

Mine are setup at 165/450ish, pretty consistantly run 5500-5700 wide open, and turned to 6200 on the dyno with no signs of valve float.

Icdedppl is running 225/575 on his crane 651 cams. I know the morel hi rev lifters call for that spring pressure, but , they also are supposed to support 7,000+ RPM, which he will never ever see.

Besides avoiding loss of control, what is the purpose of running high spring pressures? And what are the negatives of too much pressure? Lets just say theoretically, a 160/460 would keep his valvetrain under control at 6000RPM, what benefit is there to having an extra 100psi of force over the nose, if it isnt needed?

What's everyone running for springs?

Im from the camp of less is more spring pressure wise , as long as maintains control at target rpm. Especially with a flat tappet. And lighter valvetrain components.

Joe,
I'm not a cam or valve spring expert.... Spring pressures, installed heights, coil bind, lobe designs, ramp speeds, weight of the valve, retainers, psi on bottom side of intake valve are all considered ( meaning forced induction ) along with RPMs. It's a open question, all is specific to the build..... that goes along with pushrod wall thickness, tip material and material of pushrod.. My 525 build application; Isky 8205 plus spring, lightweight retainers @ 1.870 163# .070 from stack 470#, keep in mind, 3/8 valve stems "TREE STUMPS" if I had to replace 32 guides, I would of installed 11/32 valves with guides.in both engines... Do lighter weighted lifters help YES, like the Jessel's , the weight on the opposite side of the fulcrum of the rocker arm has to be considered, retainer, locks, valve weights. I have used a lot of titanium retainers over the years and bead locks, made from titanium.. same goes from valves used in BIG symmetrical port cylinder heads DART, Profiler 12, 14, 18 degree, stainless and inconel in those sizes equates to weight (MASS)...

my 540's w/Dart Pro1 Alum. Heads are 155# closed, hyd. roller cams, no problems at all with mine,
Too much spring pressure puts stress on the complete valve train, beats up the valves , rocker arms, etc. much faster.

Mine was set up for 200 closed and 600 open pressures when I redid my builds, I found out later that is not good for long term so when I had to fix some issues I took them down to 170 seat and about 560 open, hope I get some life out of it also have 680 lift I am worried about longevity now also...

Any more spring pressure then needed is just bad. It is harder on seats, valves, push rods, lifters... It also takes away power with parasitic lose. Most hydraulic lifters will float over 450#'s

I thought cams had matching springs?

Can I ask why you chose the 8205+ springs? versus a 8005A or 8005+ for instance?

Heres a good video from Dart about valvetrain dynamics

https://youtu.be/VCKVPIdVebo

Great find.... Exactly as I said too much spring robs power. Mild when do you have time to work? you seem to spend a ton of time doing research, which is great for everyone on OSO but your wife must never get any time to .. well you know.... LOL