How much spring presure should a CC 918 have at a half-inch off the seat? I just measured 139 lbs seat at 1.8", which I think is normal, and 273 lbs at 0.500 inch. Does this sound normal?

I've only got 10,000 miles on the springs, but just started getting a loud valve train noise.

 

When I bought my 918's I was told that they should have 130 lbs seat at 1.8" installed height. I checked them before installing and they were right at 130 lbs. I was also told that as long as they were above 115 with my 224 cam they were still good. Sounds like yours is stronger than mine were new?

 

OK that's good to hear, thanks for the answer. Maybe I'll keep the strings for another 10,000 then. But it looks like I might need lifters . . .

 

on my 98 artic white z28,i just bought some 243 heads off a vet with the yellow spring,my question is will i need different spring with it cam i'm running GMPP Hot, Int. 219/29 0.525 thanks jason

 

You should start a new thread for your question, it's a different topic.