If losing 10-15# is a problem, the springs had to be pretty marginal in the first place. I think you have to keep in mind what you are building, what the budget is, what the intended use is, etc. One situation that may be relevant: a customer of the shop I'm associated with wanted a cam swap on a Ford crate motor but wanted to keep costs down, change as little as possible and not spend any more than really needed. The exisitng spring pockets, available installed height, and large diameter of the valve seals made it hard to find a spring with the needed characteristics. We ended up with a CHEAP (less than $100) set of Comp single springs with damper. God knows where these things were made. However, they worked on this low rpm (peak power at 5,800) setup and are still working. OTOH, there are applications where the best spring you can get isn't good enough.

All the parts have to work together harmoniously. It's kind of a Feng Shui thing. Those springs made me nervous though, I must admit.

Rich

 

When ever I spring up,if I want the final seat pressure to be 135 then I get springs rated at 155 to install. This is with a run of the mill set NOT a $500 set Or $1825
They will be damn close after break in.

 

dude, you need to start worrying less about pressure more about spring quality and bind clearance. I don't know if i can tell you what the seated pressure of the last 4 sets of solid roller heads I've put together, but I sure as **** know the exact distance from coil bind.

 

[QUOTE=SStrokerAce;4980120]dude, you need to start worrying less about pressure more about spring quality and bind clearance. I don't know if i can tell you what the seated pressure of the last 4 sets of solid roller heads I've put together, but I sure as **** know the exact distance from coil bind.[/QUOTE

+1

The original poster needs to check everything that could cause a bind and correct it.

 

[QUOTE=1racerdude;4980189]I'm nowhere near coil bind imo.....

I checked it like this......stacked the spring in the checker...measured, then subtract that plus lift plus .100 from installed height and I was good to go. The machinist told me to check them like that, when I checked installed ht. I used a teloscoping gauge on the head the checked the spring with the retainer on top in the checker.

Correct me if I'm wrong...

Thanks

 

I don't know if I follow Mike.....

I take the spring, put it in a vice and stack it till bind and then measure that with a caliper.

Then I will take my coil clearance + max gross lift and add that to my bind number. Then that gives me my minimum installed height for the springs.

Then you have to setup the head with the valves, locators, locks and retainers you are going to use and measure what installed height that gives you with either a telescoping guage or a spring mic. Then shim or change locks to get your heights correct.

Bret