The pistons are in:




Rings were filed to:

.010" - oil rails
.020" - 2nd ring
.018" - top ring

With the rings centering up the pistons in the bores, I saw a beneficial difference in the head clearance. I also found some looseness in the dial indicator, so I took out the 3rd leg and got some even better readings on head clearance. The crankshaft throws are typical of what I've seen from Mitsubishi - around a .002" variance:

#1 = .009"
#2 = .010"
#3 = .008"
#4 = .010"
#5 = .009"
#6 = .009"

With the stock rods, some select fitting can be done to give equal head clearance, but not so with custom rods, so I'll live with it. I surely don't want to have the crankshaft indexed, ground and rebalanced. I'll just use the .010" clearance for figuring CR. That'll certainly help lower the odds on head shims.

Rod big end side clearance is tight, but right at the lower end of the range at .004-.005".

I measured the piston head volume..... it's a shade over 10ccs, as I specified (probably should have asked for an 11cc dish)

I want to wait until I measure the old head gaskets on the other engine that have been torqued down with head studs before I make a final decision on head shims, but based on today's work, the guesstimate is for 9.04 Static CR and 7.494 Dynamic CR. I've been shooting for 7.5 DCR, so I just might get lucky yet.

Today's measurement of deck clearance suggests one of several possibilities:

1) the last Diamante block that showed .017" clearance with a supposed .002 skim cut on the decks had been rebuilt before I got it (don't think so)
2) the other machinist lied to me about how much he removed
3) 3SX rods are shorter than OE (I actually measured them at .002" longer than OE spec, but it's a tough thing to measure accurately)
4) Mitsubishi blocks have a large variance in deck height

Perhaps some day I'll find the answer to that question.

Frank