Crankshaft
11-18-2012, 03:48 PM
#2
Team Owner
If the bearing surfaces look good without scoring ( minor deffects can be polished out) I don't believe in under grinding forged cranks.
The other check is straightness. The crank can't be bent from end to end. Cranks can be straightened
The other check is straightness. The crank can't be bent from end to end. Cranks can be straightened
11-18-2012, 03:59 PM
#4
Team Owner
11-18-2012, 04:01 PM
#5
Intermediate
Member Since: Sep 2012
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Take it to a good automotive machinist. He can check it for straightness in a special fixture, magnaflux it for cracks, and check the journals for scoring and if they are slightly eggshaped or not. There is not a thing wrong with having a crank turned .010, as long as the guy doing it knows what he is doing. This will not penetrate the induction hardess. These checks are not expensive.
I am not sure what you mean by "the sleeves". Has the block had sleeves installed to repair some cylinders, or maybe it is an aluminum block, or are you referring to the main bearing shells as sleeves? If you are talking about the bearings, never reuse them.
I am not sure what you mean by "the sleeves". Has the block had sleeves installed to repair some cylinders, or maybe it is an aluminum block, or are you referring to the main bearing shells as sleeves? If you are talking about the bearings, never reuse them.
11-18-2012, 04:25 PM
#6
Racer
Thread Starter
Talking about main bearing shells as sleeves should i replace when i get the crank turned? And if i need new ones should i just call eagle?
If i take the crank and get it turned .010 should i also take the cam? never heard of the brand it is EPI?
Engine Block just a 4 bolt 350.
The problem with the engine was water in number 6 and 8 and 5 and 7 and flywheel wouldnt engage the starter and when it did it would grind.
If i take the crank and get it turned .010 should i also take the cam? never heard of the brand it is EPI?
Engine Block just a 4 bolt 350.
The problem with the engine was water in number 6 and 8 and 5 and 7 and flywheel wouldnt engage the starter and when it did it would grind.
11-18-2012, 08:01 PM
#7
Le Mans Master
IF the crank has been nitrided, turning it .010" will remove the hardened surface, necessitating re-processing.
And, if you have the crank re-sized at all you'll need new bearings. That said, all it might need is a good micro-polishing. Without pics (at least) we're somewhat guessing in the dark, but any decent shop will know what to and not to recommend.
And, if you have the crank re-sized at all you'll need new bearings. That said, all it might need is a good micro-polishing. Without pics (at least) we're somewhat guessing in the dark, but any decent shop will know what to and not to recommend.
Last edited by TheSkunkWorks; 11-18-2012 at 08:06 PM.
11-18-2012, 08:26 PM
#8
Race Director
A preliminary test
a quick and easy way without a set of 'mikes is to draw your fingernail across the journals...if your nail catches then your warned its not right....then its off to the parts house/machine shop and let them explain what you need....
11-18-2012, 08:26 PM
#9
Melting Slicks
As for straightness, you can pretty much tell by putting new bearings into the block, oiling them, dropping the crank in, torquing the caps down, and turning it. The crank should rotate smootly with no change in rotational drag as it turns. If it 'sticks' or tightens as you're turning it that's a good indication that someting isn't quite 'plumb'; either you have some journal misalingment that would require align boring to correct or a bent crank or a combination of both. In agreement with the others, you can tell by visually inspecting the journals if the crank need cutting or polishing. Scratches, cuts, or gouges should be polished out but I wouldn't go turning the crank .010" under unless I had a real good reason to do so.
Those Eagle cranks are heavy and they're also real tough, so it would have taken something pretty severe to damage it as badly as you seem to suspect...
Those Eagle cranks are heavy and they're also real tough, so it would have taken something pretty severe to damage it as badly as you seem to suspect...