Thread: Head gasket and rocker arm failure - Cause?

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I appreciate all the responses. After much analysis and talking to engine building experts, here is what I have found:

The head gasket and rocker arm failures are 2 different failures.

The head gasket was most likely damaged during installation by a moron. If you look close, the location of the gasket damage in the front to back direction is inline with the dowels (which were probably in the head during install). My best guess is that theey were damaged, but did not leak until I started the engine and stared fiddling with timing, etc. I have replaced the gaskets with the correct ones, so I'm crossing my fingers.

The 3 failed rocker arms were probably out of adjustment and had little or no preload (as opposed to 1/4 turn tight to the hydraulic lifters). ALSO the guide plates were never moved to align the rocker tips on the valve stem center properly. Therefore the offcenter rockers rode on the outer edge riding up and down the edge instead of across the flat valve stem tip. This may have caused them to loosen. In any case, they were loose, which caused them to start banging even harder. I am replacing the rockers with full roller rockers, and I will align the guide plates properly before, and then after pre-loading the lifters.


Short answer is that the person who built the engine up originally did a poor job at best, and that is what caused these failures. I have decided not to tear the engine apart to look for other mistakes.

Thanks again. Thought you would all like to know what happened.

Hmm... You know, what you really want to do is tear the whole thing to pieces and rebuild it again. It has different types of pistons, even some with dishes and some without. That thing is never going to run nicely, no matter what you do to the heads. The chap who built it didn't know really what he was doing (putting different pistons in an engine ) Maybe your heads weren't torqued up properly and lifting the engine (if you lifted it by some head screw holes) just dislodged it by a couple of thousandths, thus breaking the seal of the gasket. The compression and burning proces then did the rest. Maybe the dowels arent far enough in the block, then the heads wouldn't rest properly and your 4 corner cylinders could spring a leak
I don't think the valves hit the gasket, the gasket seems to go round outside the bore, and a valve can't really hit the bore, unless there's something really wierd wrong.
I would tear it down, get some hyper pistons, pop them in, have the block cleaned, honed (maybe rebored, measure it first) and surfaced, a bent head might have bent your block. Resurface the heads, too. But check, that you don't run into clearance probs.
If you need more help, here's where to get it.
But as always, that's just my way of thinking.

If you chose to just set up the heads again and pop them on, then be prepared to tear it down again soon. It might run nicely for 50k miles, but on the other hand, it probably won't.

That's all from me,
Max

Originally Posted by MadMax

Hmm... a bent head might have bent your block. Max

lmfao yeah dude take it to the professional engine straightner hell you know take it to the engine stretcher and make yourself a big block

Top of that valve in the pic will eat anything installed on it!!!!Need new valves where ever the rockers ate into it.