Hi guys- Mr. Hopeless here again.
Working with a friend who has rebuilt a number of Enfields, I re-assembled my 1977 350cc engine with new barrel, piston, and rings.
He claims he noticed the piston "is a little to the left" in the new bore, and says I need to take off the timing cover and use a chisel to force the crank 1-2mm to the right. Otherwise, he says, the engine will seize.
I am dubious of this claim and methods, but have no experience to make a call. Can't find any mention in Snidal's or other manuals and online resources of this type of operation. Can/should the crank even move laterally in the cases?
There is currently no play in any direction at the crank, as felt from the primary side. We didn't touch anything at the conrod when we did the swap; just pinned in the new piston and rings, then lowered the barrel over it. Conrod showed zero up/down play and the permissible slight side-side movement.
It is, however, very possible that the new bore is not perfectly manufactured and the center is not the same as on the old one, so maybe he's got a point, even if the suggested remedy is not correct. Or else he's completely right and I'm just too arrogant and doubtful...been burned a few times already by Indian shade-tree mechanical lore, which is too often taken as gospel.
What do you gurus think I should do? Further tests and/or final actions? Appreciate the advice.
MD
Edit: Mr. Snidal seems to agree with me, but does say that pulling the crank from the timing side can be acceptable. Hmm...still ambivalent.
Excessive Force
Bear in mind at all times that force applied to either crankpin will be transmitted as a bending moment to the assembly of the flywheels and journal pin, thus tending to destroy crankshaft alignment. Thus, no force should be applied to the timing-side crankpin to force the drive-side pin into the bearings, for example. Nor should force be applied in the second stage to the timing-side case to force it over the timing-side bearing. In either case (no pun intended!), force should be applied only to the flywheel of the side concerned. Or as a pulling force from the outside of the case, pulling the shaft through the bearing.
Edit II: In rotating the crank with a wrench, I am feeling a noticeable change in resistance as I turn. So maybe something really is out of alignment?