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The reason I mentioned the Mark 25 cage was because of a post I found on the website by Frank Volker which is as follows and seems to back up what John is saying:
"The crankshaft padding goes back to the deflector days and carried through to the flatheads. The intent was most likely to decrease crankcase volume. I believe it was done on both 20H and MK-25 Cshafts. The 20H shafts soon became a mechanical weak spot in the flatheads; not because of welding, but because of the small cross-section of the center bearing. Eventually, all FA's and FB's used MK 25 shafts. At about the same time, we went to the special-made heavy duty rod caps and lighter flywheels. I seem to recall that even the early FB's used the '25 Cshafts." (5/8/2008)
The application I am speaking of is for an "A" looper specifically. So my question is, can the Mark 25 (non-20H undercut center bearing style) crank "unmodified" be used in the A and B loopers? If modifications were required of the cranks what was necessary to make it work. I was intrigued by the Mark 25 crankshaft idea because they are,
a) more plentiful (less expensive) than their 20H counterparts
b) are in my personal opinion stronger
This is all really interested either way.
P.S. Steve I will take you up on both offers in the not too distant future: reed cage modification (if we determine that I can do so) and the rings.
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Originally Posted by J-Dub
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