I'm approaching 50k miles on a 'built' head using all toda parts.

As I was thinking about freshening up the head, I was just wondering what the life cycle of them is.

I know that race miles and street miles are vastly different, but it would be interesting to note or compare.

 

Just throwing it out there, my very first build was over 120k when it was rebuilt, and not cause it was blown, but because the new owner of the motor wanted a bit more CR. Supertech springs, valves and oem retainers, with S2S2 cams.

 

isnt there a way to measure valvespring elasticity or whatever. I know Don told me there was a way to check it.

Everything ive been told says they are a wear item and you should prob ditch them for safety sake.

How long they last depends on revs, and how hard you drive it. I would say invest in the new valvesprings personally.

 

that is awesome man. I think that is a record for a built motor as far as what I've seen. must have been built right.

to the OP, I'd just put new valve springs in there, cheap insurance.

 

From what chunky told me, valvesprings will start to get stiffer right before they get to the point in their lifecycle before they become brittle and snap.

Basically, it's like they get stiff then boom. haha

 

well they are measured by the lbf for certain compression so you can probably see the difference from NEW specs

 

yeah maybe ask the manu what they say for tolerance but my guess is the valves should stay withen a few percent lbf compression

 

Are you saying you went 120,000 miles with S2S2 Cams and Super tech springs??

At 50K I would be thinking seriously about changing a sub $200 dollar part to protect the rest of the motor.

The way you drive is the big wild card, I've had timing belts fail around 40K (half recommended service life). I suspect it was due to long term exposer at 8000 rpms.

 

like a 2 stroke dirt bike, pulls the best right before she ****in explodes lol

 

I'd safely say, no more then two
I put my crower full race valvetrain and ti retainers through 4 change overs and 6 sets of cams.. i then switched to pro series .. the retainers on the crowers looked like **** tho...after 4 years of abuse..

i'd safely do 2 cycles.

 

That would mean you would change the springs after the engine turned over 4 times. That would be 2 cycles per spring. @9000 rpm's a valve spring goes up & down @ 1.25 times per second. Or 270,000 times per hour. Think about it.