Spring question ?

Ok so the rule is you need .50 gap between the coils at max lift....according to the spring people but if you have a fat head with a .500 lift and call bae they will send you all the stuff you need to assemble the heads but they dont worry about the coil clearance they only worry about installed heights and installed pressures this was varified by them in a phone call but pac the guy who makes the spring says this clearance is critical to spring life so who is right ? And as far as i can tell unless you have a really high ratio rocker or want really high spring pressure it will be hard to find a spring that will give you all that you need

 

BBC's here and this is the theory we run on.
At max lift the spring mfg'r recommends a max coil to coil clearance and a min, be in that range. Too much and you'll get spring surge(bad), too little clearance and well you know(bad)...

 

Spring Clearance

The way I do it is with installed height, minus net valve lift gives you clearance. I use .060" as a min. Anything less and problems, even at .060 you don't wap the motor untill it warms up. If you go with coil to coil clearance, say .050 and have 3 wraps of spring, you now have over .150" clearance. The .050 must be for installed height clearance.

Corey

 

springs

I'm in the same boat I think. I run Manley nextek and if I set the coil bind height per spec they are over 500lbs on the seat because I run a small cam. I start out with extra clearance and they lose some tension after a few laps. Then I shim them and they seem to hold pressure for a long time...over 50 laps at 8800 rpm. I need new springs now so I'd like to figure this out. My Chevy has a weak valvetrain so i'm scared to throw huge seat pressure at it. I start at 420 lbs and shim them when they hit 380.