George's video is anotated with the water temp at the time (170) as well as other factors (F/A, etc.). There are a lot of ways this could have come apart. I initally thought head gasket and possible hydrolock. The engine was locked up when we were looking the car over that evening. I've seen the results of fuel hydrolock in CBX motorcycles. Usually one cylinder/piston/rod is completely destroyed. Anyway, it is far more than a simple head gasket blow and I'm not sure if they know yet if the head gasket actually did blow. To my simple mind the amount of water that went away without a white cloud meant something had broken wide open between the water jacket and the crankcase.

 

Did you add race fuel at the event?

 

The head gaskets did not fail, the water in the block is from the #2 cylinder cracking. The block is destroyed internally and I see no evidence of detonation. The rods shattered when the pistons contacted the heads, the extra clearance was due to failed rod bearings. Why they failed I do not know.

I'm sure George will post some photos soon.

 

Head gasket intact! Fascinating.

 

George,

I've got a 5L crank and the matching "forged" rods from my '87 stroker block.

Yours' if you want them.

 

Is the cracked cylinder not a sign of detonation? Do you think that the cylinder cracked from side loading as the rods deformed? What about the hesitation felt early on, any ideas what that was? I would have bet that there were fuel supply issues causing a lean condition and some form of detonation because of that.

 

The cracked cylinder was from brute physical force/impact from the rod letting go. The skirts are broken off the pistons also. The largest piece of rod left was 1/2 of one cap, the rest is shrapnel. The only evident damage on the tops of the pistons is from impact with the heads/valves. No obvious evidence of detonation. The engine was turning at least 100 times a second, approx. 8 seconds of destruction. I believe the shudder was the rods destroying themselves and the massive imbalance after their untimely removal from the crankshaft.

Detonation would probably affect all 8, the front two and rear two are fine...for sale if anyone wants to assist George!

 

A/F was not lean overall. The hesitation George had earlier was just at WOT. Slightly off-WOT, no hesitation. I thought there was a problem with the throttle switch. Regardless, that was gone after shutting down and restarting the motor at the turnaround, and the car seemed fine at WOT on the return leg. I don't think George has had any problem with detonation before.

 

Wow. I'm just glad everything stayed on the inside.

Rich

 

Busted rods.....& cracked cylinder....I never would have guessed that.......

Damm with your and Dennis's being down with blown engines at the same time....its a sad day for norcal 928ers......

I'm also in to help out with whatever is needed!

 

Here are some of the photos that Dave sent me (resized for the web):

1


2


3


4


5


6

 

Ugh. My condolences. We'll see what my engine looks like this weekend.

 

Go big, or go home....we did both.

The strange thing is, we didn't really hear anything that would indicate that much destruction. Of course, we were at about 180mph or so. Heck, I didn't even know the engine had stopped, just that George had put it in Neutral....again, good decision!!!

Rich

 

George... that sucks. My condolences.

 

Adam,

Thanks for the offer. Dave is evaluating what will be needed. I'm letting him
propose the best solutions given the circumstances. If Dave could use these
or a set of heads offered by another rennlister, I'll get back to you.

Bill B and Michael S,

Thanks for your donations. I'll make sure these funds go to the new engine fund.
I am truly thankful for your kindness and support.