Postmortem

(07/01/02) After getting the motor on the stand, I began the postmortem. I pulled the top of the motor apart and here's what I found:

The first thing I saw what that the locking nut for the #1 exhaust valve was backed WAY off. It was much further out than the rest of the nuts and the pushrod was very loose. This is the same valve that I had seen moving just a little bit when I pulled the valve cover initially.

Then I pulled the intake manifold off and saw the #4 intake valve's pushrod all twisted up like a pretzel.

Here are the valve lifters for the #1 cylinder. The intake (right) is fine...but the exhaust is cupped all to hell.

And if you thought that was bad, check out the #4 intake lifter (the one with the bent pushrod.) It's worn all the way through. This is not good.

The first lobe on the cam is completely gone. I can't even tell where the high side was.

There are several things that may be the cause of this. First, when I built the motor, I had the static valve lash set too tight. When the lifters got filled with pressurized oil, they pumped up and kept the valves from closing. This may have messed up the cam at break-in time, although I went back and re-adjusted them and then followed the break-in procedures. The second thing that may have had an affect on it is the high-volume oil pump. It may have sucked the sump nearly dry and starved the front of the motor for lubrication.

I honestly don't know which caused it (maybe both)...but the roller cam shouldn't have that problem and I'll be using a standard oil pump when it goes back together.

Another thing that has me slightly puzzled is the pattern of carbon buildup on the pistons' surfaces. The front 4 seem to have some degree of carbon on them, but the rear 4 have none or very little. I've talked with some people who have said they've seen similar things with Edelbrock Performer manifolds, but I'm still not sure. Anyway, it will be getting a Weiand single-plane manifold.

Then I pulled the oil pan off, half-expecting the oil pump pickup to be off or all screwed up. But it seems fine.

Then I saw what I'd been dreading. A thick layer of goo, mostly metallic in the bottom of the pan.

But I pulled one of the main bearing caps and it and the crank journal look pretty good.

I called the guy who does my machine work and made arrangements to take the block and crank in for cleaning, new cam bearings and a double check on the crank journals. Then we'll start putting this puppy back together.

Next page: The rebuild begins.

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