What seat pressure and open pressure can new stock GM roller tappets handle. Just wondering because the new AFR eliminator head with their spring upgrade runs a 155 seat and 412 open to prevent "float" at high rpms

 

You want to use just enough spring pressure to get the job done. How much spring pressure is enough depends on valve train weight, natural resonance, cam profile acceleration rates, rpm etc etc.
how much spring pressure the hyd lifter plunger will withstand depends on internal clearances, oil temp, oil grade.
generally 130LBS seat pressure is enough. If you just got to buzz the hell out of it then get a rev kit. "Hydra rev"
The new Beehive springs have less mass, higher natural resonance (surge) and will rev higher with less spring pressure. Usually no rev kit is required.
The lifters are just one of the components that are affected by spring pressure. Rockers, pushrods, valve guides will wear more with excessive ***** out spring pressure.
That means shorter engine life.
Consult your cam manfacturer to get the right setup for your needs. You need to balance valvetrain life, with max rpm capability and cam lift rate. Haveing the max race set up is not much fun if it wears out the valveguides after a 4-5000 miles from $$$excessive pressure$$$.
The beehive springs are worth the extra $$$'s.
ifg you really need more than say 6200-6400 rpm you should be looking to a solid roller cam setup.

What cam are you planning on using?

 

Thanksfor the reply. I'm planning on using comp cams 280 xfi 230/236 @ .05 576/570 GVL w/1.6 RR

 

if you want a "Better" setup, i would contact Comp cams and
ask what the spring requirements are for that cam. Ask about the beehive springs. Generally better valvetrain control at high rpm with less spring pressure. (more engine life)
The spring on your heads sound like a bracket racing spring for a roller or radical solid. Its a lot of pressure for a street car that has to last a while.

You shouldn't have to rev much more than 6000rpm for max performance so a killer spring is not called for.

 

Id say 155 is too much for a factory OEM hydra lifter. They were intended for 100K durability not 6000+ rpm. I would at least use an aftermarket lifter.

PS, I have 140seat and 370 open and thats not counting the hydrarev spring (and they are comp non-oem hydroller lifters). Probably runs 165-170 seat at the lifter with the hydrarev. I think I measured 50lbs on the hydarev spring for my lift.

 

I am trying out the 995's from Comp. We'll see how this goes.

COMP Cams Valve Springs: CCA-995-16 - summitracing.com

 

For my LPE219 cam with 560 lift I used the stage 3 springs from TF with 125 seat and 376 open pressure. They are suppose to be good for 600 lift. So far with stock 90K lifters they take 6500 RPM runs with ease.

At first I called comp cams and for a 600 cam or less they suggested the 987 springs.