Hello all
i'm looking for some new shell bearings for my engine.
but i'm under whether i have an undersized or oversize crank and if so by how much.
as far as i'm aware it's a standard 1275 crank from a 1990 mg metro a+ engine.
will i be able to work this out by measuring the crank? or will it be on the shell bearings i removed?
Regards J
Undersize Or Oversize Crank?
Started by
duds_12
, Sep 19 2011 02:07 PM
6 replies to this topic
#2
MRA
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Posted 19 September 2011 - 02:23 PM
Normally you would have an undersized crankshaft, this is due to the bearing journals wearing with use, they wiould then need a regrind, however you could have a standard crankshaft that hasn't been reground yet.
CHeck the old bearings that came off the crank, as a guide, however if the crank needs a regrind then it would normally come back with a tag to say what size bearings you require.
CHeck the old bearings that came off the crank, as a guide, however if the crank needs a regrind then it would normally come back with a tag to say what size bearings you require.
#3
duds_12
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Mini Mad
Posted 19 September 2011 - 02:30 PM
well i got the engine complete over a year ago and before that it was running in a metro until it was written off.
so as far as i'm aware the crank has never been removed from the engine let alone reground.
so are you saying i should look to get standard shell bearings?
so as far as i'm aware the crank has never been removed from the engine let alone reground.
so are you saying i should look to get standard shell bearings?
#4
dklawson
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Posted 19 September 2011 - 02:30 PM
As above. I cannot imagine how you would ever have an "oversized" crank. It should be standard or reground to a smaller size. Do not buy new bearing shells until you have the existing crank checked for its condition and what its current diameters are.
#5
MRA
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Posted 19 September 2011 - 02:44 PM
There was a special crankshaft for the 1098cc that used larger bearings, can't remember what, just have a feeling they were ford or something similar....
But that is about as far as it goes....
But that is about as far as it goes....
#6
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Posted 19 September 2011 - 03:05 PM
As long as the journals are round, not tapered, scored or damaged in any way then you may be lucky and get away with replacement shell bearings.
#7
AndyMiniMad.
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Posted 19 September 2011 - 04:19 PM
I believe the standard size for the crank from the MG engine...possibly all 1275 engines is 44.44mm...( big end) so if you have a micrometer then you could measure it...But as said above if it has any marks on it you would be better off having it reground to the next size....Also the shell bearings have std stamped into the back if they are...well....err... standard.
Edited by AndyMiniMad., 19 September 2011 - 04:20 PM.
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