valve spring pressure

[jamie2370]

350 sbc, flat tappet hydraulic cam(stocker motor) Thinking I have valve springs going causing car to not turn over 5500rpm. I used an on car spring tester. I got 110ish to just open valve and around 250ish at .500 lift(1/2" measurement), tested with that valve closed and I could spin pushrod with my fingers. Looking at Pac 1409x , it shows like 150/390. I'm thinking the springs are gone??

[FireSale]

There is a design difference between beehive and conical springs. Read this link before making your decision.


https://www.chevyhardcore.com/tech-s...sign-dynamics/


I run PAC 1427 conicals in my SBF 302 with N351 heads. They are right below the 1409s you are looking at. BB Chevy stock elim springs. They are 200/500 at 1.85 with my .597 lift cam. 6500 in the 1/8 all day.


BTW I'm solid roller all the way. If you are stock, make sure the springs you choose are allowed.

[gsa612]

What type of lifters Schubeck? or a stock type,if so are they shimmed for limited travel?.It will matter on the spring pressure you can run. gsa612

[pmrphil]

Originally Posted by jamie2370

350 sbc, flat tappet hydraulic cam(stocker motor) Thinking I have valve springs going causing car to not turn over 5500rpm. I used an on car spring tester. I got 110ish to just open valve and around 250ish at .500 lift(1/2" measurement), tested with that valve closed and I could spin pushrod with my fingers. Looking at Pac 1409x , it shows like 150/390. I'm thinking the springs are gone??

Some of the on car testers vary a lot in the readings - I've had them off by 45 lbs. when checking. They should be used for reference, and the spring should be checked with a calibrated spring tester to be absolutely sure of what you have.