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AIR POWER
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Discussion Starter #1
Well today my 455 olds started to have a knock down in the crankcase while going back to the trailer at the end of the day. When the knock started it lost allot of power and started to knock really bad, the engine has been running like a stripted ass ape until now, I idled the boat to where the knock wasn't so bad back to the trailer. I got the boat back home and started it to see where the knock was coming from and it died, siezed up. My guess is I spun a bearing on a rod? I dont have any oil restrictors or any oil mods, and I have been running the engine allot WOT for the past six years. The motor just had the heads rebuilt and I put a new timing chain, cam, roller rockers, hei dist. etc..., the engine had a problem last year with the famous milk shake problem after installing over transom bassetts, so I tore it down and cleaned all the milk out and revamped the water pressure problem to fix the milk shakeing. Now four weekends out this year another problem with the knock,(I think spun rod bearing). I have and 396 chevy truck block to build up but am in the process of making it happen. If anyone can give me some advice if this would be a major problem or just a simple pull the motor and replace the bearings I would appreciate the advice. Thanks.
 

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The only thing I can tell you is the Olds crankshafts are difficult to find, so if it's been turned too many times you might have a problem finding another one. I bought a boat today that I am going to part out and it has a Olds 455 in it, if you need parts let me know I might have what you need. It's a extremely common problem the Olds engines run into.
 

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AIR POWER
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Discussion Starter #3
So will the crankshaft for sure need to be turned? Will the rods be ok? can I just put new bearings in it? I guess I will need to get the engine out pull the oil pan and see what exactly happened and how far I will have to go. I have never spun a rod bearing so I was wondering how big a problem it is.
 

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Olds power

So will the crankshaft for sure need to be turned? Will the rods be ok? can I just put new bearings in it? I guess I will need to get the engine out pull the oil pan and see what exactly happened and how far I will have to go. I have never spun a rod bearing so I was wondering how big a problem it is.
Plenty big. Had you shut it down as soon as the noise started you MIGHT have had a chance. Since it locked up, chances are the rod broke, or the cap came off/bolts broke, and interfered with the crank rotation, which usually screws up the portion of the crank that hit the pieces that were in the way, and/or breaks the block....The rod, even if it hasn't come apart, is junk. Once a bearing starts spinning the big end is no longer round, so a new bearing will just spin again. The crank journal is more than likely toast as well. Even if it would clean at .020 under, the heat factor has wiped it out. The Hardin Marine Olds engines were a good piece, steel cranks etc etc...Trying to find those pieces today can be tough, unless you find a complete marine engine sitting around. Like hot rod has mentioned. Maybe, just maybe, you could take the 2 engines and try to make a good one, but it won't be cheap......Now wait for the "switch it over to BBC/BBF" comments to come along......In the future, if there is a future for your boat, stop the engine anytime it starts eating its self up. Get out the paddle and start stroking it to the ramp. The difference is usually a couple of thousand dollars after driving it to the ramp knocking.......Call or PM hotrod, because when I get back in town I may be buying the Olds myself, and MY Olds runs great as it is. Never hurts to have some spare parts to play with..............Especially IF they are original Hardin stuff...............MP
 

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AIR POWER
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157 Posts
Discussion Starter #5
I will get the engine pulled out here this week and find out what it looks like if the crank is surely junk, I will not be fixing it, but if all it would take is a little machine work and new bearings then I will fix it. I guess I will wait and see.
 

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E-7 Sheepdog (ret)
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The "Died, siezed up" part is what really concerns me, and is the point where I will be greatly surprised if you get off cheaply.

As MP said, the engine locking up really indicates a broken rod, which is the big end coming apart, not breaking in half. Even if the rod didn't "break", it's trash, not worth trying to save by a resize, straighten, and re-heat-treat.

Spin a bearing and it sends metal all over the place, as well as that bearing (journal and rod end) get VERY hot, very fast. Ruin the temper on the crank journal as well as the rod. You'll find some ugly black/bluish colors inside there when you open it up I fear.

Since it locked up, chances are the rod broke, or the cap came off/bolts broke, and interfered with the crank rotation, which usually screws up the portion of the crank that hit the pieces that were in the way, and/or breaks the block
Friend of mine bought a blown-up 460 (yes, very cheap).
Rod failed at about 10 hrs, #8
Rod nut improperly torqued and unscrewed itself (found nut in bottom of oil pan, undamaged).
Broke at full throttle, oil pan looked like a buckshot blast had hit it at 20 feet, rod in 3 pieces, one threw out thru the pan, after failing to make it out twice at the pan rail (2 breaks in the block).
We found all the parts.
2 crank counterweights had spent quite a few revolutions using the broken off rod side (with the tight bolt in it) for a pinball (the pan rail and piston skirts) before finally finding the soft spot in the pan itself.

Previous owner swears someone built the engine for him.

We know the previous owner (co-worker), and are 100% sure he assembled it himself, and screwed up torquing the rods, and won't admit to it. Doesn't matter, just that Sam and I know.

He's not a bad mechanic (aircraft firm he works for witheld to protect the innocent (us LOL)), but he HAS a tendancy to shortcut things, and to not admit to a screw up if he can avoid it.
 

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I am near Spokane Wa. at Fairchild AFB, I am in the Air Force.
Right on, thanks for serving. I'm a former squid. :D

Shipping is going to be bad on a shortblock, I just shipped a shortblock to the bay area in California and it was $396. I wonder if the military has a less expensive way to ship it? Of course this is assumining the shortblock I have is good, since I was told it is good but I have yet to check it... I'll get back to you in a couple days, after I've had a chance to check the shortblock out.
 

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AIR POWER
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157 Posts
Discussion Starter #10
Pulled the oil pan off and cant find any blueing on the rod or any metal parts all over the place or a broken rod. I can just turn the engine over by hand and there is a rod tward the back that looks like it was on its way to shelling out. I think the bearing siezed to the crank but now is unsiezed.
 

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Sounds like good news! Measure the crank or take it to a machine shop and have them measure it. I would not just put new bearings in without at least having the crankshaft checked out.
 

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I had a similar thing happen to my camaro engine,

started out as a rod knock, but I kept running it to get it to my shop, stood on it once I got to my shop and she seized solid,

the rod with the knock was dumping all the oil pressure so the other rods were starved and running dry,
they free'd up on there own, to the human eye the crank didn't look that bad, but measure it and it was screwed, for sure take it to a machine shop and have it turned,
replace all the bearings, rods and mains and take a real good look at the cam,
make sure it wasn't oil starved as well,

might be a good time to freshen the engine up, if you're going to all that trouble
 

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AIR POWER
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157 Posts
Discussion Starter #13
I am definetly going to take the crank to the machine shop, from what I can see right now it looks as the only thing that got screwed up was the rod bearing. I am not sure but I wonder if last years milkshake had anything to do with this?
 

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Cleaning

I am definetly going to take the crank to the machine shop, from what I can see right now it looks as the only thing that got screwed up was the rod bearing. I am not sure but I wonder if last years milkshake had anything to do with this?
Regardless of how you decide to fix, it must come completely apart and be throughly cleaned. Every oil passage brushed out with hot soapy water, blown out with the garden hose, and air pressure......AND DON"T forget to totally disassemble and clean the oil pump.....MP
 

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Have that rod end checked also, most of the time it goes egg shaped.
Be prepared to replace the rod, and maybe the one beside it, if not all of them........This is scary trying to evaluate an engine condition long distance, and if this isn't done right, you'll be doing it again in a few weeks.........Please don't let time and/or money restraints make any important decisions for you........MP
 

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AIR POWER
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Discussion Starter #18
Damm Money Pit you are full of all kinds of negative news. I am keeping my head up and am going to take the engine to the machine shop and have them rebuild the bottom end for me. Hopefully I will have it back running in a week or so.
 

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AIR POWER
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Discussion Starter #20
Getting Fixed

Hot Rod I dont need any parts, my crank is good and the whole bottom end is at the machine shop getting fixed. UPDATE on why I spun a rod, someone put a 10qt moroso oil pan on and didn't put the right oil pump pickup on instead they used the stock pickup, when I was out cutting corners and accelerating I airated the oil pump which starved the rod bearing furthest from the oil pump. The machine shop will have the bottom end done friday and install restrictors on the mains just in case, and the right pickup along with the new pump and other goodies will be here tommorow. So yay It will be back in the water saturday!!!!!!!
 
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