IS there any physical difference between the La360 vs. magnum 5.9 Crankshaft???

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MonkeyMadness

MonkeyMadness

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I was inspecting my 5.9 that i planned on swapping into my 65 barracuda and I found that one the rod bearing journals had been turned down to .020" under and the main bearing had been turned to .010 and showed a ton of damage to the crank.
Now I plan on doing a full tear down and rebuild before the swap but I don't plan on reusing the crank. So i'm on the hunt for a new 5.9 crankshaft and I was wondering weather the LA 360 crank is a direct swap or if there is a difference and what it was. I just don't want to get stuck buying the wrong parts....

Also if you have a good crank taking up space and would like to sell it for money and a friendship that will last the years to come, please let me know! :thumbsup:
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thanks
J
 
The part number cross references the same on both RockAuto and AutoZone's websites when checked for a 91 D150 1/2 ton pickup with 360 and a 2000 Ram 1500 1/2 ton with a 5.9

I know the balancers and flexplates are different though from LA to magnum
 
Is there any particular reason you're averted to having the crank ground to a standard number like 020 or 030? That would be a standardized oversize and bearings are readily available in those sizes.
 
txstang84 said:
Is there any particular reason you're averted to having the crank ground to a standard number like 020 or 030? That would be a standardized oversize and bearings are readily available in those sizes.
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No I was just looking to keep it near stock size, I plan on running a whipple charger and i'm not quite sure what kind of stress that could put on the crank or bearings. I would like to keep it from spinning a bearing or cracking something...
 
I see your concern, but unless you're really turning up the wick, .020 or even .030 shouldn't be a problem as long as it's properly ground clearanced and installed. If you're that concerned about breaking a crank under boost, you really ought to step away from a stock crank, LA or otherwise, and go with a forging at which point, you could probably opt for zero balance.
 
txstang84 said:
I see your concern, but unless you're really turning up the wick, .020 or even .030 shouldn't be a problem as long as it's properly ground clearanced and installed. If you're that concerned about breaking a crank under boost, you really ought to step away from a stock crank, LA or otherwise, and go with a forging at which point, you could probably opt for zero balance.
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No its just going to be a streetable sc setup around 8-11lbs boost "at most". I just didn't want to take a chance but it sounds as if my worries are unfounded... lol If so that makes me feel much better.

I guess my next step is to have if check by a shop to see if its usable and if so turn it...
 
I hope the flywheel bolt holes are the same between the two, but if it's the same part number you would think it's the same.
 
AJ/FormS said:
8 to 11 is serious business. this can easily be over 500hp, even with a small cam, but more importantly is the torque increase.
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Originally I was only looking for 5-8lbs but Flyin Ryan has assured me the stock bottom end in the magnum can handle 8-11lbs with no issue. (he wants to be in the 15-18lbs range)
Which brings me back to why I was looking for a new crankshaft.

Normally I build BMW v8's and all the rotating mass is forged and pretty bullet proof, you have little to worry about while on boost even in the high teens. But being this my first American v8 on boost I want to tread lightly when it comes to either boost or damaged parts i.e. undersized cranks
 
I pushed up to 12 in my stock bottom end 302 (with a 020 under turned crank, stock rods, and stock iron heads) for over 10K miles before I sold the eng/trans to a friend of mine. It never missed a beat and was a daily drivable 11 second car.

Seeing that you've built other boosted engines in the past, you know full well the biggest things you have to worry about with boost and stock bottom end parts is going to be making sure you eliminate any detonation (better gas, conservative timing), open up your ring gaps to suit the extra heat produced by the increased combustion temps, and use an appropriate (read: colder) spark plug...with 8-10lbs, I'd honestly recommend you go 2 down on the heat range.
 
Now on the other hand, we ALL know power is addictive, especially horsepower...and if you get the feel for 10lbs, your butt callouses will get thick and you'll want more...and eventually you'll run it to beyond the capabilities of the stock rotating assembly, at which point in time, the crank won't matter because you'll probably crack a stock hyper piston.
 
Looking at the discolouration of the crank journal, and the condition on the bearing itself , was there any indication of a coolant contamination issue?
 
Max1196 said:
Looking at the discolouration of the crank journal, and the condition on the bearing itself , was there any indication of a coolant contamination issue?
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There was a bit of surface rust on the first 4 rocker arms on the left bank but i figured it was normal for a junk yard motor.
I personally have not run it yet. I pulled it out of a junk yard Durango earlier in the year.
 
Front cover gasket area was a problem on that style ,gasket rotten then leaks, and check the heads for cracks..
 
Surprisingly i got lucky with the heads. They look new and have no cracks between the valve seats and show no warpping.

I have not checked the gaskets but i will be doing a full tear down and rebuild. I have to find the sorce of the copper shavings I found in the oil pump pickup.
 
LOL @ the tread lightly statement.
These engines were never designed to do anything but move a car or truck within the law limits.

It is a shame there not stoutly built like a lot of the foreign engines are stock.
 
Cranks are the same, balance is different....you can run 8-10 safely as long as you dont have any detonation....the magnum short block is tougher than most people think.
 
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