any thought on this...thanks

 

overrev?

 

it could have been caused by a number of things. can you give us some info about the parts in the head?.... ie springs and seat pressure's at various heights and also how big of a cam. what was the valve lash set at? does the cam have any type of markings on it?

 

I've seen something like that on a dsm that broke the timing belt. When the pistons came up into the valve it broke the rollers on the cam followers.

 

call hardtopguy hell know in a sec.

we get s2k heads in left and right with crap like that

 

the head was built by Earl so hopefully he will chime in with some of the details...the cams are stock and had some slight markings on the lobe where the roller was split in half. Technically the head was not over-revved (taken to 9k) since it could rev up to 10k. From what I recollect it was rev tech parts used. Thanks for the feedback.

 

i would take the rest of the rockers out and have them all fluxed/rayed to see if hair line cracks are forming within the other rollers. the other info i was aking for might hold the key to your answer.

 

ouch, never saw that happen before. Be sure to check the cam lobe closely for a flat spot on it. No idea why that should have happened.

 

Holy crap a roller broke? IT broke clean off too.

I'm gonna blame it on the material.

 

thanks, yep no flat spots on the cam...I hope it was material based but will check everything as Miller stated.

 

wow that is one clean break. Looks like it was cut with a laser.

 

well the team and I had an opportunity to change out the broken roller tonight, however, it gets even worse. Once we got it back together we noticed a slight noise which caused the initial inspection. So we checked again and found a similar crack on the intake side on a different lobe (non-vtec) roller. This was a single crack which was even more percise and straight. This is very puzzling since everything else checks out fine...

 

Flaw in the casting and it just cracked :

 

Valves adjusted to tight or loose maybe? I dunno.

 

doesnt seem to be naything like lack of oil or anything, doesnt look like anything is burnt up

you could send it to a couple of places and have them X-ray it and check the structure of it, but i really just think it was a flawed piece

 

thanks everyone, valve adjustment seemed fine, all within spec. Oiling was okay too as seen. Just unusual that two pieces were possibly flawed. One on the intake side and the other exhaust side. Both the non-vtec rollers. I visually inspected the others and they seem fine but will have to send them out to be xrayed..