Engine Autopsy

psfracer

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So as I detailed in my other thread, on my 3rd qualifying pass at SCSN9 in Las Vegas, I lost the motor at the 1,000 foot mark going roughly 140-145mph. Thankfully the belly pan kept oil off of the tires and I was able to stop without going into the wall. The car is fine, just the engine is damaged.

So, on to the engine. At the track I pulled all of the plugs, all looked fine except one had oil on it, but none showed any signs of damage. I also removed the valve covers and found 2 bent pushrods.

Got home on Sunday, and decided to start pulling it apart on Tuesday to see what I would find. So far I am pleasantly surprised.


Engineautopsy1.jpg~original

^^^^the autopsy table.

No water in oil, indicating the head gaskets were fine and didn't fail. The head gaskets themselves looked good. Everything on the top end was in order except for two bent pushrods. 7 pairs of roller lifters in great shape, however 1 pair will not come out on #7.

EngineAutopsy2.jpg~original



Engineautopsy3.jpg~original



I was really worried that a piston might have come apart and really screwed up the cylinder head(s). That is not what I found. Cylinder heads look good except for some minor pitting in one chamber, which will clean up when the heads are resurfaced. I did the water trick on the ports and chambers, all held water overnight, but I still suspect a couple valves may be bent and need replacement. However nothing obvious with a visual inspection.

EngineAutopsy5.jpg~original


Engineautopsycylinderhead1.jpg~original



Engineautopsycylinderhead2.jpg~original


Titanium retainers and intake valves all look good. Valve springs look great also.

I was surprised and relieved that all the pistons were in one peace, and the cylinder walls all looked good. In the picture below, you can see it looks as though the exhaust valve left a pattern on the rear two pistons on the driver side. I was shocked that the engine turns over when I put a wrench on the crank. However the #7 piston does not move at all, while all the other pistons do. So it seems to be obvious I lost the rod on #7. This weekend I am going to pull the short block and disassemble. I am hoping the block can be reused. So far it looks like it can be, but won't know for sure until Saturday. No cracks or damage visible on the block anywhere, however the oil pan is shot. I am also expecting the crank to be shot and unrepairable, but we will see.

Engineautopsypistons2.jpg~original



Engineautopsypistons1.jpg~original



More to follow this weekend.
 
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lethe

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Hope it turns out well for you. It would be a real bummer to lose the block.
 

skwerl

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If you posted elsewhere, I missed it. I just saw the title of this thread and your name and muttered "oh no" under my breath. I'm relieved it doesn't appear to be a major catastrophe at this point.
 

tjm73

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In the other thread you said the pan has a hole in it. Any notion what poke the hole yet?

EDIT: Sorry i missed that you said #7 wont move. At least it's not #8.....
 

psfracer

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I got video of the last pass to. Why does it run the best just before it explodes? LMAO. 1.27 60' time, but already started slowing down to the 1/8th. Best 1/8th was a 5.49 @ 127.

I will have the video up in a few.
 

psfracer

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In the other thread you said the pan has a hole in it. Any notion what poke the hole yet?

Yep. Rod from #7. When I turn the motor over all the other pistons move except for #7, so it seems pretty obvious. At this point the only questions are (1) did the block make it and (2) will the crank be repairable? Probably a no on the crank, but hoping yes on the block.
 

dysan

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Well, from seeing blocks from my builder who builds and runs Ford big block dragsters, it takes a lot to ruin one of those blocks. He just lost a rod in his slower dragster and all his block needed was one or two sleeves and then some machining.

Good luck.
 

Timmbo

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Good luck with it. Hope it doesn't get too expensive.
 

mikeysgt

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Wow man I missed whatever other thread you're talking about also. Sucks about the motor but luckily that's all that was damaged.
 

psfracer

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Definitely. Belly pan kept oil off of the tires, so I was able to stop without hitting the wall.

Here is a picture of the last pass.

SCSN9mycarweb-1.jpg~original
 

TurboX

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Wow that sucks, good luck on the repair and hope block is ok.

Any idea what happen, I know you said rod failed but what rods were they and what were they rated too ? I was under the impression that you were no where near pushing what this mill was capable of.
 

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