120 lb valve springs

[Tom87GN]

I just found out from a machine shop (thanks Josh) that my stock cam has been pushing on 120 lb valve springs for about 3K miles. The guy says he used a hydraulic spring checker and it registered at about 120 lbs.

What springs are these? I bought them from Modern Muscle down at the Nats a few years back. I told them I wanted replacements for the tired stock units and they handed me the bag of springs and told me that was what I wanted. I was too green back then to know what I was asking for!

I'm pretty sure I've been reading that the stock cam should not see more than 100 lb of seat pressure. I think it's time to find out of the cam is still in good shape or not.

Anybody with any input here would be appreciated.

 

[salvageV6]

At what installed height did he measure them at?

Did you give him the specs. or did he get them?

If not they may be correct and just measured wrong.

If you want to send me a spring or two to test I'd be happy to do it.

Email me.

If you wish to change them you can't go wrong in MHO. with Comp. Cams. 980's with no cups on the stock cam.

Important thing to find out is how they were measured?

 

[Tom87GN]

I've got the springs at a different engine shop now getting measured at an installed height of 1.727". They will be giving me all the specs on the springs by the end of the day today. I'll post the findings.

 

[Tom87GN]

If anybody is still reading this thread, here is what K-Motion found with the springs.

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At an installed height of 1.727" they checked out anywhere and everywhere in between from 100 lbs to 115 lbs. Most were around 105 - 110. They were also measured at 1.340" (varied from 256 lbs to 272 lbs) and at 1.249" (varied from 289 lbs to 311 lbs).

They found coil bind to be at 1.135".

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The fact that the springs vary that much concerned both myself and the guy that checked them. He said that their shop will not install a set of spring on one of their motors if they vary any more than 5 lbs across the board. He also stated that he didn't think that if my springs were similar to these that it would harm the stock cam.

Any ideas?

 

[blackplague]

They are probably lt-1 super springs

the standard lt-1 spring is 100#. The lt-1 guys do have a super spring rated at 120#. Maybe that's what they are.

 

[Tom87GN]

Oh, yeah. I forgot to say that what I'm more interested in right now is what to do with my springs that are currently installed on my motor. They are the same springs that were tested above.

I was pretty sure that Modern Musclecar told us they were LT1 springs when we bought them.

Thanks for the reply, blackplague!

 

[Carolinaturbot6]

Well, it's common knowledge that the more spring pressure used, the less life the stock cam will have. Far more experienced fellas than myself have real reservations about using heavy springs with the stock cam in our cars.

100lb. springs...maybe.

110lb. springs...not me.

 

[salvageV6]

I'd be happier with the C.C. 980's myself.

I tested 5 of my set and they were within 2lb.s of each other with the nominal at 85lbs. No cups.

 

[Tom87GN]

Does anybody out there think that I'm already in trouble with my stock cam? I have had these springs on my motor for about 2 years and have put about 3,000 miles on them.

I heard that I can mark the pushrods and run the motor for a few seconds and then check to see if they moved. Will this be enough to tell if my cam is affected or will I have to remove the cam to find that out?

 

[Tom87GN]

Hey, salvageV6, I sent you a personal message for some help on the CC 980's.