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#1
12-26-2019, 08:11 PM
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My Engine Carnage
So a while back I made a full throttle pass on a favorite back road and blew a hole in the upper radiator hose. The next time I drove it I noticed a slight ticking sound and a slight drop in oil pressure, maybe 5-8 psi, so I parked it and started putting together a spare 400.
Fast forward 3 months to yesterday, Christmas day, I decided to drive the car one last time to a family gathering a few miles away. At first there was no noise and the oil pressure was right where it should be, but a short way down the road it would make an occasional noise that sounded like the flexplate had a crack in it. On the way back home the oil pressure was rock solid, but the noise started getting louder and then BAM!!!! I started pulling the engine today thinking that the flexplate grenaded, but a quick look at it killed that theory. Once the engine was out & the oil pan dropped, this is what I found....     A HF flux core welder and a little JB weld should have it like new in no time. Engine specs: Daily driver with 14,400 miles 420hp to the tires Never sprayed. 455 +.060 E-heads 10.23:1 SCR 8.6 DCR BRE(?) forged pistons Scat forged H beam rods factory 455 crank Bottom filled block
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No! Do not try! Do! Or do not. There is no try. - Yoda 1967 Firebird Restoration 2005 - 1/25/2017 
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#2
12-26-2019, 08:18 PM
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Sorry for your loss....
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'65 Tempest 467 3650# 11.30@120.31 |
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#3
12-26-2019, 08:52 PM
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Thats a significant failure for a pretty mild, street driven 455.
How bad did the block take a beating?
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"Those poor souls have made the fatal mistake of surrounding us. Now we can fire in any direction" 1970 Trans Am RAIII 4 speed 1971 Trans Am 5.3 LM7 1977 Trans Am W72 Y82 1987 Grand National |
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#4
12-26-2019, 09:02 PM
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WOW... how did that happen? Those rods should not have napped like that... What brand where they? I would think they would have bent and not snapped....
Please keep us updated... SPEED SAFE, NICK
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"The grass is not greener on the other side, its just fertilized with different $h!t" |
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#5
12-26-2019, 09:05 PM
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Was that an Eagle rod?
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 Johnny US Army Retired1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph 1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car. 1980 Formula 350 Pontiac back burner project 1972 LeMans 350 Pontiac |
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#6
12-26-2019, 09:11 PM
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Very strange break in the rod. Looks like a rod bolt broke first and then a cascade of events happened.
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1967 Firechicken, 499", Edl heads, 262/266@0.050" duration and 0.627"/0.643 lift SR cam, 3.90 gear, 28" tire, 3550#. 10.01@134.3 mph with a 1.45 60'. Still WAY under the rollbar rule. |
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#7
12-26-2019, 09:11 PM
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OP stated SCAT H beam rods. Looks like good rod bolts too. Wow.
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1970 GTO 400 Atoll Blue, PS, PDB, A/C Was M20 4 speed, now has Keisler RS600 5 speed. |
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#8
12-26-2019, 09:50 PM
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Usually a noise getting progressively worse then bam is a spun bearing
Almost seems like a rod bolt came loose Because the rod journal doesn't seem to be hurt that bad But I am on a cell phone
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If your not at the table you're on the menu A man who falls for everything stands for nothing. |
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#9
12-26-2019, 09:58 PM
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My WAG;
Guage recording air pressure as Oil starved & pumping air, Rod bearing scored then spun, then rod bolt loosened, THEN Rod rammed piston into head to break Pin. Then fod bolt broke, and rod broke Darn shame, as that was a nice bottom end. |
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#10
12-26-2019, 10:33 PM
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In the first pic the one capscrew obviously broke in half inside the rod cap. But the other side of the rod cap shows the threads in the rod and you can see the rod bolt with a few threads on it at the edge of the pic. Did that bolt loosen and fall out? Can’t see all of the bolt but it’s odd that it didn’t break in the rod or strip the threads. Idk
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#11
12-26-2019, 10:43 PM
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Looks like the bolts are ARP 8740's if my eyes are seeing correctly? I've seen H-beam rods bent into "S" shapes without snapping and here we're looking at a rod that seems to have shattered like a cast rod. Interesting that the cap came through the carnage in good shape.
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Mick Batson 1967 original owner Tyro Blue/black top 4-speed HO GTO with all the original parts stored safely away -- 1965 2+2 survivor AC auto -- 1965 Catalina Safari Wagon. |
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#12
12-27-2019, 12:24 AM
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Is that a crack in the block running from the location of where the rod impacted?
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79 Trans Am WS6 71 Formula 72 Formula 71 Firebird 69 Firebird |
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#13
12-27-2019, 06:44 AM
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X2, I think that is a crack in the block!
How many times had those rod bolts been torqued up?
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! Last edited by steve25; 12-27-2019 at 06:51 AM. |
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#14
12-27-2019, 08:19 AM
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When get the rest of it apart could you post up pictures of the back side of rest of the lower rod Bearings and also wipe off and take a picture of the Bearing side of each rod cap?
Please also state which cylinder each cap and Bearing come out of. Thanks in advance!
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
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#15
12-27-2019, 08:39 AM
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Do I see this correctly? Crank journal is not horribly scored. Rod big-end is not burned black like it was oil-starved. One rod bolt broken, the other apparently not.
None of this bottom-end catastrophe is explained by "a hole in the upper radiator hose". I think a rod bolt unthreaded itself, the other couldn't take the strain of going on alone. Oil pressure was down due to rod cap flexing and knocking until the second bolt broke, and then the piston got shoved "all the way up". The crank throw probably took a few good whacks at the dangling rod. "I" would be verifying torque on all the other rods before disassembly. First Guess: Our multi-piece rod had under-torqued/under-stretched bolts. |
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#16
12-27-2019, 09:30 AM
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Perhaps 1 rod bolt was never torqued? or oil starve caused the bearing to spin (No blueing from nuclear-level heat!)
Maybe the rare Little-end seizure occurred, and took out the rod. |
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#17
12-27-2019, 10:12 AM
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If you look close at the biggest part of what's left of the big end of the rod you can see where the back of the Bearing melted into that half of the rod Bore, but yes the rpm was not high enough to light the oil off, but there was enough load to snap off that other overloaded rod bolt I would say.
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
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#18
12-27-2019, 10:58 AM
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I suspect the OP took the one rod bolt out.
Also suspect the crank journal is actually the back side of the rod bearing/s. Clay FWIW when skinny oil gets too hot, it makes an excellent flux for welding/brazing rod bearings to cranks |
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#19
12-27-2019, 12:39 PM
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To answer a few questions; I put this engine together 2-3 years ago and and ALL bolts (ARP throughout engine) were torqued to spec using ARP assembly lube. I was super anal on the assembly to make sure that all the torques were right.
The rod bearings were in the pan so the pics show the actual journal. One of the bearings got flattened out, but the other is in pretty good shape considering. I'm going to check the torque on the other rod bolts and I'll take pics of the bearings as they come out. One of the rod bolts was in the pan relatively unscathed so the theory that a bolt came out makes the most sense to me so far. I heard a sound that could have been the bolt slamming into the oil pan and a few revolutions later, the engine quit. Here a few more pics: The piston & what's left of the rod  The bottom of the cylinder took a few hits from the bottom half of the rod  The most damage on the rod journal was around the oil hole. The rest wasn't all that bad.   The number 6 piston is the one that broke the rod and smacked the head. I also have quite a few bent valves in both heads. I haven't pulled the timing cover yet to see what the chain looks like. 
__________________
No! Do not try! Do! Or do not. There is no try. - Yoda 1967 Firebird Restoration 2005 - 1/25/2017
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#20
12-27-2019, 12:44 PM
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Hard to believe you could go 14k miles with an improperly-torqued rod bolt?
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