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Re: Benefits of a Midget crankshaft?
Posted: Sun Jan 25, 2015 9:40 pm
by les
Modifying the Minor flywheel adds another two holes, if two or even one dowel is then added, how much metal is left? The Minor flywheel bolts, or more correctly, set screws, are dowel like, in so much as there is unthreaded metal under the head, and I believe the flywheel is located on the crank by a recess.
Re: Benefits of a Midget crankshaft?
Posted: Sun Jan 25, 2015 10:16 pm
by bmcecosse
Correct! When I modified a Minor fly, I made sure the extra holes are 'tight' so the set screws will act as dowels. I used the Marina fly as a drill jig... The fly has yet to be used - although it has been mounted on a 1275 Marina crank to check it fits.
Re: Benefits of a Midget crankshaft?
Posted: Fri Mar 20, 2015 9:48 pm
by millerman
To complete this thread:
Marina flywheel fitted and new clutch plate and thrust bearing. Have completed 800+ miles and no problem so, should be ok for the long term
(Hope I'm not tempting fate
)
Very pleased with the engine, quite a change from the tired Marina engine. Out of interest I tested the cylinder pressures and ALL showed 155 lbs/sq.inch, hope my gauge is not faulty!
Thanks all for input
Re: Benefits of a Midget crankshaft?
Posted: Fri Mar 20, 2015 10:54 pm
by bmcecosse
155 is 'ok' but not fantastic... Was that hot engine and throttle held open? The main thing is that they are all the same....although 170/180 would be better!
Re: Benefits of a Midget crankshaft?
Posted: Fri Mar 20, 2015 11:19 pm
by millerman
Bores were just good enough to get away with new rings, ideally should have had a rebore but no excessive oil consumption so far.
Pressure taken with hot engine and throttle wide open
Re: Benefits of a Midget crankshaft?
Posted: Sat Mar 21, 2015 9:16 am
by bmcecosse
It's fine really - I couldn't remember what the rebuild spec was.