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  #16 (permalink)  
Old 05-12-2019, 10:44 AM
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That is one of the best I've seen in awhile.

Have you figured out the chain of events that caused it, the big end still on the crank at least indicates it wasn't the bolts that let go.

Bogie

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  #17 (permalink)  
Old 05-12-2019, 02:07 PM
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If the locks are still installed (looks like they are) and the valves are stll in piece, then I' thinking the piston came apart. Were these hypers or forged?

Also, a full tear down of the remaining pistons might reveal something. Or.....be a big fat waste of time depending on your point of view - hehe. Did you save the pan, timing cover, intake, anything?
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Old 05-12-2019, 02:59 PM
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I would look at hydrolock...when the cylinder wall in a stock block cracks, and water rushes in, that cylinder will go hydraulic and the piston and rod will simply explode. I quit using stock blocks for any 4 barrel race engines for that reason.
The first time it happened to one of my engines was with a stock 400 block, both rear cylinders blew out and the cylinder wall fragments showed the wall thickness was only about 0.040" on a 0.030 overbore. That was the last stock 4.125 block I ever used.
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Old 05-13-2019, 12:58 PM
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I found more of the piston. It was over there on the other side hanging around the #2 intake port being a distraction no doubt. I may need a leash on it if it can't stay in it's own yard next time. The left head says the valve head came off first.

I going to cut open the oil filter can and see what's in there. It might be the wrist pin. When I took the filter adaptor off and the left cylinder head the whole LF corner at the bellhousing mount surface came off with it.

I have no idea at what RPM this started to come apart at. I never look anyway. I just go and let the chip do it's thing. This one was supposed to be a 7500. Maybe it was wrong. Who knows.
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Old 05-17-2019, 07:44 AM
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Blown Engine

That's not how Positive Crankcase Ventilation is supposed to work!
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Old 05-19-2019, 08:30 PM
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I got time today to finish the little disassembly needed. Iíve never had to cut a rod bolt head off before haha! I had to use a hammer and punch to knock out the little I couldnít cut with the cut off wheel without hitting the crank journal. Surprisingly the crank is not harmed nor the bearing. I could probably reuse them but I wonít. I can save the heads and 5 pistons and 6 rods and the crankshaft. More fun pictures added.
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Old 05-19-2019, 08:39 PM
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Every SBC crank I've ever seen go through an explosion like that, ended up showing as cracked when magnafluxed….so get it checked before you decide to re-use it, or maybe even before you let it take up shelf or floor space.

Didn't seem to matter of they were cast stock, Cast aftermarket, or forged stock or aftermarket....just 1 stock forged survived uncracked...but with a big rod bolt head shaped dent in one journal. A buddy had it welded and used it until it threw a second rod(pulled beam in half on Pink rod) and then it was cracked, in several locations.

Looks like those are the new Eagle FSI rods??
Not that I'm blaming them at all. Big end was still around the crank.
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  #23 (permalink)  
Old 05-20-2019, 07:35 AM
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I've seen a few survive but you're very right, it's already getting looked at.
The rods are Scat Pro Series with the ARP 7/16" bolts.
I'm pretty sure the valve broke first, the rogue head of the valve exploded the piston and the loose end of the rod beat up everything till it finally cam out at a high rate of speed.
Mike Jones has a new cam coming, the crank and my new block are at the shop while I wait for the heads and giant bill to show up.
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Old 05-20-2019, 08:59 PM
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I can't believe that crank is straight. Is your shop going after straightening it? Personally, for the price of SBC cranks and mail box posts, that would be a mailbox post here.

Kidding aside, if that crank works out to be salvageable and makes it through a feature, then PM you're address and I'll mail you a case of of beer of your choice.
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  #25 (permalink)  
Old 05-20-2019, 09:55 PM
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They haven’t called me on anything yet. They are pretty backed up right now.
You’re right, it’s just a throw away crank but if it is usable it’ll save me a little on balance work.
This is just a play-do toy anyway. I don’t wanna throw a lot of money at this one. This only had 9 nights on it so there that
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