I need to know the minimum open and closed spring pressures for my roller cam:

Erson 294/302
254/260 at .050"
.629/.629" lift w/ 1.7 rockers
108 lobe sep

I already am set up with a set of roller springs, that were setup for a .560/.570" lift roller cam. Not sure what the pressures are.

Is there a formula that a guy could figure this out on his own? graemlins/beers.gif

You need to talk to Erson but I don't like solid rollers with less than 200 minimum on the seat & 500-550 open.
Prefer 225/550. This is for a reasonable roller like yours assuming it's a billet.
Some rollers take a bunch more to control them, it depends on the lobe & this is something the designer should know.
You don't want to run this much on anything but a billet which is all I would consider for a solid roller.

My opinion is one of the worst things you can do with a roller is not running enough spring,,, it beats the crap out of the lobes & rollers if they aren't controlled

Jeremy,

First of all, ask Erson!
They are really the only one who knows the answer.
My 502A2LUN has 290/300 at .020, 255/264 at .050, .630"/.630" valve lift, and 110 LSA. For 24 years I have used it on the street and other longevity applications with 210 lbs on the seat and 525 lbs open.
In its' small block version, I had 2 Camaros finish the 24 Hours of LeMans with this spring pressure.
Check with Erson....

UDHarold