i've searched but i couldnt find anything to confirm if you can run s3's or kelford 280's with stock pistons & valves ?? (9 mivec motor)
any help or experience would be great thanks.

 

I'm running S2's and was told to upgrade my valve springs. I can imagine you would also need upgraded valve springs for the higher lift S3's.

 

Yeah you really shouldn't even run the 2's or even kelford 272's with stock springs...

 

Aaron mentioned to a friend of mine just the other day that S2's shouldnt be revved past 7200 on stock valve springs.

S3's would raep house on everything.

 

i said nothing about stock springs.
with upgraded springs has anyone ran stock valves & pistons with s3's ??

 

are you referring to the clearance "valve touching piston" ?

 

correct

 

To the OP i just asked this very question last night. Here are some of the responses i have got. take a look. https://www.evolutionm.net/forums/ev...eded-asap.html

 

S3's wont make valves hit pistons

 

Not trying to call you out but do you have proof of this. Im really looking for this info and need to know. Any proof or research you could show be greatly appreciated. So far from what ive gathered there wont be enough of a clearance but then again i have oversize valves.

 

Heres one car that does it, i know of a few others also

http://www.youtube.com/watch?v=mTOTgAhS-Q8&feature=fvst

 

Do you know if they had to change anything to make them work?

 

fixed link

what would you change? it says right in the description, stock motor. if thats not enough proof, i dont know what to tell you. s3's work on stock motor

the only difference in the s3 from the s2 is .2mm higher lift on the intake side. its not a huge difference in peak lift

 

Not so much worried about lift as duration when the valve is chasing the piston. Im also running oversize valves. had a couple people who do head porting question it thats why im just trying to be 100% sure thats all. Thank you for the input! greatly appreciated!

 

so if your running oversized valves, did you have your whole head built?

if so, im gonna assume it was decked. now at this point, it depends how much was taken off the head