Thread: Need some valve train help.

I recently installed some S3's in the SE-L. The issue I'm having now is there no compression in cyl. 4 due to the exhaust valves open @ TDC. I confirmed these by hooking up my compressor to the cyl. and rotating it to TDC. Air comes out the tailpipe. I loosened the exhaust cam while on TDC to take the spring pressure off the rocker and sure enough the valves sealed. That leads me to believe the valves themselves are good. Prior to the cam install, I didn't have this issue.

I then proceeded to take the exhaust cam out and inspect valve train bits. The rocker looked fine and both the notch disc and the shim where there and looked good. I then proceeded to get the lifter out. I thought at first it was stuck open, but after reviewing the FSM, I forgot you have to push in the check ball to release pressure. So I did that and it moved freely. I then proceeded to bled all 4 exhaust lifters per the FSM and put them back in. They all behaved the same during the bleeding process, so I don't think the issue is the lifter. For shits and giggles, I swapped #1 lifter and the #4 lifter and reassembled everything. And of course, I'm back to square one...exhaust valves open @ TDC on #4...fack. So now I'm wondering if the cam lobe is not right...

Does anyone have any thoughts as to what might be happening here? I'm really tired and this thing has gotten the better of me this weekend. Unless someone has any ideas, I think my next move is to put the stockers back in and see if the issue stops. Like I said, the motor was running fine before the cam install.

That sounds very wierd like a bad cam grind are they new or used ?

sounds like the valves need to be ground down...the way you explain it is just like having valves that are too long. Only way to know is either put in another set of S3 cams and see if the problem is there, or put your S3 cams in another head and see.

Cams came out of my engine that were used from Nov. 26, 2011 to Sept. 9, 2012 in a daily driven SR20DE engine with regular oil service change intervals.

I don't know what else to say. The cams worked great in my car when I removed them and they were treated well while in out of the engine for the few weeks they were out.

That doesn't make any sense at all if the car ran and drove fine at the time it was taken apart and then you swap cams as long as everything was done correctly and the timing is correct the only variable that could be bad is the cams.

hmmm very weird indeed.. IIRC (could be totally wrong) some aftermarket cams (non oem) have the distributor drive cutout into both intake and exhaust cams, now could you have possibly mixed them up? so intake is exhaust ect.

that might be totally silly of me to suggest but it came to mind an figured i'd throw it out there.. i'm sure someone can verify if this is even possible or not.

Exactly, hence my recommendation.

So the problem is only on cyl 4. could it be worn exhaust valve seats? This would cause the valves to sit higher. So when you are looking at your cams on cyl 4 compression stroke the cam lobes should be facing away from each other.

Only one cutout. Not possible with these cams. I appreciate the input, though. At this point I'll take any suggestions.

ahh, maybe its the kelfords that have that then.. thanks for reponding.

can we get some pics?