Dan
Since the block is being welded (hopefully in an oven?) you'll almost
certainly need to remetal and line bore afterwards.
Before you go too far, how far undersize is your crank?
Ours was 100thou under, and needed grinding. After a lot of thought, we got
a Phoenix crank (advantages - no 68 years of fatigue, no sludge holes to
reseal, bigger journals and a rear oil seal). The only disadvantage is the
cost!
In Malcolm Greens book on MMM, he mentions a conservative estimate of 500
million revolutions for a typical PA crank in about 1997 - seeing that you
appear to drive yours like we do, you might consider that number. . .
We also bought Carello 'look-alike' rods, made by a local company that
builds engines for ski boats and off-shore racers. They take Mini big-end
shells (1 5/8" dia I think).
Re the thread, I can't help. If it's 20 tpi at that diameter, I don't think
it can be Whit. Is it perhaps 26 tpi (British Standard Brass or Cycle)? Note
that the thread on the nose of the original crank is UNF! So anything is
possible.
Bearing in mind how much car you have to take apart to fix the clutch later
on, I would certainly have it relined now: your engine machiner may have
good recommendations on this work. While ours was in pieces I also replaced
all springs, pins, etc in the clutch cover assembly - S&V have all those
bits.
If you havn't done this already, lighten the flywheel: I took about 4Kg off
ours, per a 'factory' drawing published a few years ago. I can feel the
difference, and I think that more still would have been better.
Regards
Dave Dwyer
J2 (with PA engine!)
TA, TC
/// unsubscribe/change address requests to majordomo@autox.team.net or try
/// http://www.team.net/cgi-bin/majorcool
/// http://www.team.net/mailman/listinfo
/// Archives at http://www.team.net/archive/mg-mmm
/// Send list postings to mg-mmm@autox.team.net
|