I have a question about valve springs. The set I got with a set of heads I bought spec at .550" max lift, 130# @ 1.800" and 350# @ 1.200".

What I'd like to know, is how well these would work with the cam I'll be installing? The cam specs are 230*/236* @ .050", .490/.490 lift, 110 LSA. (Comp XE274)

The springs Comp reccomends for the cam are 105# @ 1.700" and 295# @ 1.250"

Would it be ok to use the valve springs I already have on these heads? These heads were rebuilt, but never run, so the springs are still new.

 

I wouldn't be afraid of them,but cam break in will be crucial,along with avoiding prolonged time at idle.If anything,they will benefit high rpm performance.
Just my opinion,but Lucas oil stabilizer is the poop for cam break in!

 

Do not use Lucas in your oil. If you want added anti scuff protection use GM EOS in the oil. use Shell Rotella T oil.
No other oil additives or modifyers or "stabalizers" are required.

Read the tech articles on flat tappet cams and recent oil formula changes on both Comp Cams and Laser cams internet sites.

Are You useing stock style ball stud rockers or roller rocker arms. If your using stock style rockers you're at the max as far a spring pressure. More than nessessary. A comp cams #981 is all the spring that is called for with this cam.
Reducing the spring pressure will improve the cam and rocker life. (increased retainer installed height) I'd pull one spring off and check its actual pressure first thou. may turn out to not be an issue at all.

The specs are for .600" open lift 1.800" 1.200" your maximum open lift is .500" around 280 to 320 lbs at open spec of .500" would be about right. if you installed height is 1.8" check it for pressure at 1.30"

 

You can remove the inner valve springs during the intial cam braking. helps a lot. just don't race the motor till you reinstall the inner spring coils.

 

Why not?I've broken in every engine I've built for the last 5 years with it,and since using it I've not had 1 cam failure.Can't be that bad.

 

I'm not using the stock type rockers, I have a set of Pro Magnum roller rockers. How would I figure out the spring pressure at .500? I don't know the spring rate though, and I don't actually have the heads here yet.

 

You don't figure it out. You measure it. Take a spring off and measure the installed height. Then compress the spring to that spec - .500" and measure the pressure. If you don;t hav a spring pressure checker take one or two springs to a auto machine shop that does have one.

 

I figured thats what I'd have to do, but I was hoping I could do it before the heads arrived. Oh well.