valve spring pressure

jamie2370 · 07-08-2019, 03:07 PM

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 · 07-08-2019, 04:47 PM

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 · 07-08-2019, 04:51 PM

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 · 07-08-2019, 06:19 PM

Quote:

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.

07-08-2019, 03:07 PM	#1
jamie2370 Member Join Date: Dec 2014 Location: Perry, GA Posts: 331 Likes: 11 Liked 239 Times in 90 Posts	valve spring pressure 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??

07-08-2019, 04:47 PM	#2
FireSale VIP Member Join Date: Feb 2014 Location: Lakewood Washington Posts: 1,407 Likes: 29 Liked 237 Times in 126 Posts	Re: valve spring pressure 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. __________________ Dale Shearon 68 Mustang 6394

07-08-2019, 04:51 PM	#3
gsa612 Senior Member Join Date: Jan 2008 Location: 100th Meridian Posts: 569 Likes: 116 Liked 280 Times in 139 Posts	Re: valve spring pressure 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 Last edited by gsa612; 07-08-2019 at 04:57 PM.