[skier207]

I often see listed on performance heads for use with a hyd roller or solid roller cam only. Does anyone know what if any difference is in springs between a hyd and a solid roller cam given the cam specs were virtually the same?
I am asking because I have a set of GM performance heads that I am finding little info on. They are fully assembled new oval port heads I am unsure of the valve springs that are on these heads if they check out pressure wise I still don't know if I should use them.
Thx

 

[bracketchev1221]

If the pressure checks out, and they are tall enough for the lift you have, then there is no reason not to use them.

 

[StevenS]

Most springs already installed on heads that I see say Hyd roller or solid flat tappet cam only. But check the pressures and coil bind to really see.

 

[steelcomp]

Hyd lifters are limited to the amount of spring pressure they can tolerate.

 

[bradley67]

This ^^^^^^^
And that also varies between lifter manufacturers and within their own product lines.
You could also adjust the load the spring puts on the lifter by playing with the installed height - keeping in mind the cam parameters and valve stem length.
The shorter answer is - take the heads apart and measure everything you actually have.

 

[billdini]

Springs are rated by width, height, seat pressure and pressure at lift and coil bind. Most flat tappets seldom exceed .500 lift but rollers cams in most cases do. You want to use a spring that fits the machined spring seat diameter, max lift, coil bind and rated spring pressure at seat and at lift to meet the cam specs. Using a heavier spring will only use more HP then needed and using one with to little seat and lift pressure will float. If coil bind is exceeded damage to the valvetrain will occur.

 

[Camaro_fever68]

Always match your springs to the cam you using

 

[GuysMonteSS]

Always match your springs to the cam you using

This ^^^
When I was in the process of ordering my 315 AFR's from Mike Lewis I asked about this.
Mike installed the proper springs and set them up for the custom Bullet solid roller cam he got for me.
He also used tool steel retainers to save a bit of weight.
The peace of mind knowing that we had the right springs for the cam was well worth it.
Guy

 

[skier207]

Thanks for all the reply's, my main concern is there a difference in a hyd spring vs a solid spring. I have a set of completely assembled brand new in the box GM heads #12462899 w/2.25 in and 1.88 ex valves, I have found pretty much zero info on these. It sounds like as long as they spec out with the cam I am using they should be good to go.

 

[Wolfplace]

Thanks for all the reply's, my main concern is there a difference in a hyd spring vs a solid spring. I have a set of completely assembled brand new in the box GM heads #12462899 w/2.25 in and 1.88 ex valves, I have found pretty much zero info on these. It sounds like as long as they spec out with the cam I am using they should be good to go.

Normally there will be a difference between the springs
That said it is also possible a spring could be used across solid & hyd flat tappet as well as some milder limited RPM hyd roller applications if it can be set up properly for the combination
Usually a hyd roller, especially the more aggressive performance oriented will prefer more pressure & rate though & solid rollers are normally substantially more in both seat & rate

First thing you should do is find out what your have for a spring so pull one, measure your installed height & have it checked for seat & open pressures as well as bind number

Don't know where you are at but if you want to send me a spring along with a few bucks to return it or a return label I will be glad to test it & send you a computer printout of its specs,,,,,,,,

 

[skier207]

Normally there will be a difference between the springs
That said it is also possible a spring could be used across solid & hyd flat tappet as well as some milder limited RPM hyd roller applications if it can be set up properly for the combination
Usually a hyd roller, especially the more aggressive performance oriented will prefer more pressure & rate though & solid rollers are normally substantially more in both seat & rate

First thing you should do is find out what your have for a spring so pull one, measure your installed height & have it checked for seat & open pressures as well as bind number

Don't know where you are at but if you want to send me a spring along with a few bucks to return it or a return label I will be glad to test it & send you a computer printout of its specs,,,,,,,,

Thanks for the info/offer I will have someone locally check the springs out, if I don't find anyone I will take you up on your offer.

 

[BillK]

If they are the way they came from GM they should have the 12462970 springs on them. The heads are the 502/502 crate engine heads.

1.514 spring
140# @ 1.940
325 lb/in spring rate
1.200 coil bind

Thats from my 2006 GMPP catalog.

 

[skier207]

If they are the way they came from GM they should have the 12462970 springs on them. The heads are the 502/502 crate engine heads.

1.514 spring
140# @ 1.940
325 lb/in spring rate
1.200 coil bind

Thats from my 2006 GMPP catalog.

Thanks that is great info! I have looked everywhere for specs for these heads, I have the newer GMPP catalogs but these are not listed. They are absolutley new not no head bolt marks or any signs of being dismantled in any way.