MC18 and mc21 crankshafts

**Mon Aug 19, 2013 7:04 am » Post: #1 » Download Post**

Hi all
Can anyone tell me if late MC18 and MC21 crankshaft's will fit early MC18 crankcase's.
I have two early MC18 motors in need of top and bottom end overhauls and I have access to late MC18 and MC21 cranks and barrels. The only Knowable difference to me is the centre bearing in the MC18 and MC21 crank, early MC18 crank's seem to have a separate oil seal where the late cranks have a seal intregral with the bearing. Are the bearing's interchangble as the early crank centre seal is impossible to source.
cheers for any input on this issue.

**Mon Aug 19, 2013 2:15 pm » Post: #2 » Download Post**

No, the R5/6K/MC21/MC28 cranks do not fit the R2/4J.
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Andy.
NSR-WORLD.COM

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**Tue Aug 20, 2013 7:06 am » Post: #3 » Download Post**

Thanks Andy.
Will have to put Plan B in to action

Owen

**Tue Aug 20, 2013 2:10 pm » Post: #4 » Download Post**

It shouldn't be too hard to track down a set of R5K/MC21/MC28 cases.

A late (1990~) crank will need machining to fit the 1989 cases though, and you will need '89~ pulse coils, as they have different spacing to the 87~88.
_________________
Andy.
NSR-WORLD.COM

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Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

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