Please leave a comment if you have any idea what it could be.

 

Hey,

What cams are in the car?

What mod's have you done to the valve train?


-Bink

 

Stock head and GSC S2's

 

has to b something with the rocker arm looking at the wear pattern on that lobe, although to the left of the lobe looks like to much material on the wrench part of the cam.

 

maybe its the angle but it doesnt even look like the lobe is centered on the rocker

 

yeah snake bite it is not centered on the rocker. this is actually my car and when we looked at it, it looks like it is off center of the rocker. We had built the motor and when done this is what happened. It sounded like a really bad cam tick I removed the valve cover and this is what we saw. The GSC 272's have been in the car for almost 3 yrs.

 

bump

 

looks like that roller is jacked up, its making contact with the cam or was looks grinded up now. Remove that Roller and check it bet its wacked out big time. Gunna definitly flush everything youll have some metal all over that engine from the fatigue.

 

looks like the roller axle gave way.

 

only 1 lobe?

Looks like maybe the lifter seized or stuck in the full expanded position, meaning the only thing to give was for the cam to wear. Or maybe just a bad lobe on the cam.

I have seen this exact wear on a cam before but it was not on a Mitsubishi, but on a GM LS6 with an aftermarket cam. Car was on n2o and have been over reved multiple times. The aggressive ramp rate, mixed with over reving, caused the lifter wheels not to roll as designed and just started wipping off the lobe of the camshaft.

 

What valvesprings? It only took material off the sides of the lobe and not the actual contact patch of the rocker to the lobe. I am wondering what else is in the head that could have been doing the machine work we all see.

 

Head is completely stock. It was making contact on the side of the lobe, the contact was the lobe hitting the side of the rocker. when we rotated the crank the clearance on that lobe was close. Springs compressed fine with no problems rocker roll like they should and look fine when we took them out. I having shaving all through the head right now. We are going to rebuild the head but want to make sure this is not going to happen again. thnx for the reply's.

 

definately inspect that rocker & feel if the roller is moving around.

can you see wear marks on the rocker itself, on either side of the roller?

if not, what wore @ the cam?

 

I've seen this before on web cams, it was a problem with the material used to make them.

Not to say that is the case here. What valve springs?

Are you sure they are GSC cams anyway?

 

How do I get in contact with Greg from GSC? I am new to the forums, but recently one of my S2's on a 500 mile fresh cylinder head has likely destroyed the exhaust side of my head. I am absolutely sure the cam bearings were torqued to spec in the right procedure, every moving part had assembly lube, and yet just the exhaust cam and the cylinder head on that side is trashed. Almost as if the camshaft wasn't straight, the intake is perfect. I double check everything and follow the FSM for procedures, I am trying to figure out what caused the issue, as I have a hard time believing it was the work of my machinist or myself. My 05 VIII needs a new cylinderhead and likely a set of cams. I can post pictures here or can start a new thread, I hear Greg is who I need to speak with to figure out what happened.

Also would love to know who on here does oil analysis because this is some nasty, dark oil. And it's amsoil dominator 10w-30 with less than 100 miles on it. My first engine failure ever in more than 6 years working on cars I am STUMPED as to what caused the issue, and why it was isolated purely on the exhaust side of the cylinder head.