competition cam springs 975-12 FTW

[QWIKSTRIKE]

As some of you know the 975-12 competition cam springs are a drop in repalcement for our old worn 100k plus valve train. What most people don't know is that they have a seated 55lbs at 1.5" installed height. Our seated pressure is 35lbs at 1.378" installed height. So when installed on our cars head the installed compettion valve springs will theorecttically have a seated 72lbs at 1.378" according to their spring rate chart. You double the seated pressure for just 60.00 delivered. These springs should take a mild cam say like the 264 8.5mm .342" of lft easily. Just a little FYI for those that don't know. If you plan on spinning more than 7200-7400 rpms going better is wiser.:naughty: :biglaugh:

 

[Doward]

Curious here, but on a pushrod engine, you have to worry about things like collapsing a lifter with too much spring pressure.

Since we have solid lifter buckets, in an OHC configuration, I assume that doubling the spring pressure will have no ill effects, other than increasing the internal force needed to drive the engine?

 

[QWIKSTRIKE]

Very good question...I see it possibly as causing more cam wear than normal and more force to open them....yes. The crower spring rates is 90lbs at 1.378" installed height so you aee it should not be an issue.

 

[starscream5000]

Great info guys . I always assumed it was 55lbs at the same height as stock springs.

 

[suprarich]

Good post Anthony, don't forget that the 80 lbs is just seated pressure. The open pressure is a big factor on springs as well. Not sure what the open pressure on stock is, but the BC springs is 200lbs and the comp springs are 127.

 

[theKnifeArtist]

would this give the same rpm capability with a stock cam?

 

[drjonez]

welcome to 10 yrs ago.

either way, a great cheap mod for the 7M!