Hello guys!! I need your knowledge!!!

I have an Evo 4 jdm (96), and yesterday I check the valve springs because I have a evo 8 head, so I decide to compare the valve springs on both!! and I saw that evo 4 valve spring looks stronger and bigger than evo 8 valve spring...

That can be possible??? maybe Evo 4 springs support more high rpm than stock evo 8 springs?

 

they are bigger and have more seat pressure. BUT. evo 8 springs and retainers are behive. Much lighter. the spring has to control the weight of all moving parts. including springs and retainers, not just valve. total mass is less for evo eight. so less spring is needed.

evo retainer is 4 grams
evo 4 retainer is 14 grams.

springs are lighter as well. dont remember by how much.

seat pressure is 52lb evo 8, and 62lb for evo 4. BUT spring pressure/to rotating weight is less for evo 8. meaning there is higher holding power and less friction for evo 8 springs.

 

94AWDcoupe thanx for your answer!!! Yeah, I saw difference between both springs and reteiners!! So, what do you recomend to me??

I bought a set of Kelford 272 cams. I have forged rods (pistons too) and FP Black... so, what can we do?? bought springs or not??? to rev to 8,000