Engine Autopsy

NDSP

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Sorry about the motor. That is how I lost my last big block ford. Bent rod. Two of them.

On a side note. Why did you choose to go with the CJ styled heads and not A460s? The U turn the CJ's exhaust port does would keep me away from them, or do those have raised exhaust ports?
 

psfracer

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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.

Yeah crank and rods were rated to 1500hp with the ARP L19 rod bolt upgrade. But, if you have a rod bearing go south (my theory at this point), it doesn't matter if the rods are rated to 2000 hp, you going to lose it.


Sorry about the motor. That is how I lost my last big block ford. Bent rod. Two of them.

On a side note. Why did you choose to go with the CJ styled heads and not A460s? The U turn the CJ's exhaust port does would keep me away from them, or do those have raised exhaust ports?

It was my first 460 build, I went with the P51 to stay within the "budget". Now I am looking at a N/A class and looking at a C460 head. There is a weight penalty to run those, but since my car is well above the minimum weight it wouldn't matter anyway. I am still considering the TFS A460 at this point, but leaning towards the C460.

These P51s did all right though, 9.16 @ 150 on motor only, 3340lbs. Not too bad. But I need to be 8.30s all motor to be competitive in the class I am looking at--so I need to be around 490-520cfm on the intake on a 598-632cid motor.
I would love to build a 632 but the billet crank with a 4.75 stroke would be very expensive, while the 4.500 stroke cranks are pretty common. Probably will end up with a 604cid C460 motor.
 
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quiksilver15

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Man the wrinkle of those 29.5" slicks looks awesome... Sucks about the motor, but dam going for 8.30s all motor sounds CRAZY!!
 

BruceH

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Sorry about the motor but thanks for posting up the autopsy. I'm really curious as to how the rod and main bearings look.
 

psfracer

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Got it apart today. It was a rod bearing failure on #7, which got so hot the crank was almost black on that journal, which made the rod fail. The rod bolts (ARP L19, a step up from the ARP 2000s), were fine. The crank was fine except for that one journal, which is so trashed that the crank is gone. Bummer as the rest of the crank looked perfect.

The bottom of the pistons looked like a grenade went off, but they held together, I am impressed with these diamond pistons.

I will post some pictures tomorrow. I don't know if the block can be saved as there is some damage to the cylinder bores on the very bottom of a couple of them. Not sure if it can be repaired or not.

A piece of rod flew up and got wedged between the block and a cam lobe as the cam was turning. What this did was stop/lock up the valve train instantly, which in turn ripped a few teeth off of the belt for the belt drive and bent the top gear.

So hoping the block can be saved, top end is fine, 7 pairs of lifters fine, cam trashed, rods/pistons trashed, crank trashed on one journal.
 

lethe

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Bummer. Was the damage to the bottom of the other cylinders from pieces of the #7 piston/rod?
 

stkjock

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Damn Paul, that sucks, so if the block can be saved you need a new rotating assembly?
 

tjm73

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Did it spin the rod bearing? Such a small event leads to such carnage.

My brother has a 418W in a '88 Ranger and he had the thrust bearing fail and it lead to a lot of carnage. Messed up the trans even.

Hope your block can be saved.
 

VTXFrank

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First off, let me say how sorry I'm you've had this happen! Man, that really sucks to lose your motor right before Christmas!

"There is smoke on the top end…" 9.21 @ 118 mph lol.


Blown motor, a 9.21 1/4 and it looks like you beat the guy in the right lane. I reckon if you have to lose the engine, this isn't a bad way of it happening.

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

Brother, I would LOVE to have a 1920x1080 copy of this for use as my wallpaper!
 

05stroker

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Sorry to see this. This though is what I ment in my thread about my damage being minor.

Good luck with the rebuild.
 

psfracer

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Did it spin the rod bearing? Such a small event leads to such carnage.

My brother has a 418W in a '88 Ranger and he had the thrust bearing fail and it lead to a lot of carnage. Messed up the trans even.

Hope your block can be saved.

Yeah, this is really all of my fault. Two passes before this last pass, I noticed that the oil pressure was low on the return road and the engine was a little hot. However the next morning when cold, the oil pressure shot right up to 75 psi and everything looked normal. The next pass I thought was normal as it ran a 8.98 @ 150 while not spraying until the 60 ft mark and stopping at the 1000 ft mark.

But with 130 passes on it already, I should have caught that low oil pressure on the return road as a sign to stop and tear down the motor and re-bearing it.
 

psfracer

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First off, let me say how sorry I'm you've had this happen! Man, that really sucks to lose your motor right before Christmas!



Blown motor, a 9.21 1/4 and it looks like you beat the guy in the right lane. I reckon if you have to lose the engine, this isn't a bad way of it happening.



Brother, I would LOVE to have a 1920x1080 copy of this for use as my wallpaper!

It could be good just before Christmas….. as you know what will be on my "list":boobies::boobies::boobies::boobies:

I can send you a 1920X1080 copy if you want.
 

psfracer

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Damn Paul, that sucks, so if the block can be saved you need a new rotating assembly?

Well I would need new pistons anyway as the bore would go from 4.500 to 4.600. But yeah if I would have torn apart the motor before this calamity the crank and rods would have been fine.


SO I have 6 rods and pistons that look "normal":

GoodRodPiston.jpg~original


Whats left of #7:

RodPiston7.jpg~original


#3, this neighbor on the crank sustained a lot of collateral damage and actually was worse then #7 as far as the block.

RodPiston6.jpg~original


RodPiston6side.jpg~original


Bottomofpiston.jpg~original


On to the crank. All of the journals looked good enough to where they would easily clean up, EXCEPT for #7, where all of the shit began:

Crank1.jpg~original


Crank2.jpg~original


Crank37.jpg~original


Oops:

Crank7damage.jpg~original



Cylinder bores look ok, especially since I would be going from a 4.500 bore to a 4.600 bore for the future build:

A460block.jpg~original


However at the very bottom of two of the cylinder bores, they are chewed up at the edges. Not sure if this can be repaired, perhaps sleeved, or if the block is ruined.

Blockdamage.jpg~original
 
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dysan

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Looks like you can have that sleeved. My engine builder's block looked much worse than that and he is having it sleeved.
 

WARstang

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Aside from the discoloration, I think your crank might be ok, with a .025 turn (maybe even .010). I do not see any deep grooves.

The only thing I would worry about is that area being annealed from the heat.
 
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