It is now hurry up and wait time on this project. After mulling the situation over this week, trying to decide whether or not to get new pistons or to try to repair and run what I've got, I finally settled on just sticking with the pistons I have, and making a slight modification to the pin hole to try to address this oil ring support rail issue. Getting new pistons was going to cost me about $2000, and take another 1-3 weeks, plus they would be uncoated so if I wanted to run the dome and skirt coatings I'd have to send them off for that also. The time/money drawback to this approach pretty much eliminated it from consideration for me. Also, I did some measurements on the pistons I have, and found them to be in reasonably good shape from a wear standpoint. For example, these pistons are supposed to run with 0.004" skirt clearance, measured on the skirts 0.4" up from the bottom. All 8 pistons were right on this number. Plus the skirts still have the coating intact. The three pistons that are scuffed have .002" to .003" wear in the scuffed area, right up at the oil ring groove. This will certainly contribute to some piston rock on these three slugs, but I think I can live with that for a while.
The major consideration for me is the movement of the oil ring support rail. By grinding the lower oil ring land so it is vertical where the pin hole goes through, rather than tapered, I'm hoping to keep the dimple in the support rail from starting to eat into the bottom of the ring land. I think it is easier for it to do this with the taper at the pin hole, since there is very little material there that needs to be deformed at first. And once it starts cutting in there, the little ramp formed there may give it the start it needs to keep going into the rest of the ring land. Of course this is only a theory. There is no way for me to know if grinding the lower ring land vertical will solve the problem, without tearing down the engine again. So, my conclusion this week was whether I get new pistons or not, I'm going to have to tear down the engine again after running it for a while to see if this problem is solved. And if it is not, and I have brand new pistons in the engine, I'm just wasting the money on them. So, I'm sticking with the slugs I have.
Right now, everything is at the machine shop. The block is going to get honed in #4 to eliminate the little dimples in the bore from last year's dyno disaster, and get the oversized 4.508" bore piston. That piston and the rings arrived this week. After looking at the remaining bores my machinist thought that it would be best to touch up the hone on the remaining 7 cylinders and get new rings, so we're going to do that also. The rods are there to get magnafluxed and checked for cracks, to make sure that I don't have a rod failure like I did in 2014. And I also took in the pistons to check the pin fit. Finally, the new valve guides for the new heads arrived this week, so I dropped those off with all the other stuff.
My machinist has promised to make his best efforts to get the block honed and the short block components back to me by this coming Friday. Assuming I can get the new rings by then, I will be able to get the short block re-assembled next weekend. The new heads should be done by the following week, so with luck by July 24 I will have the piston to valve clearance check done, and the heads permanently installed, and maybe the front of the engine and the valvetrain too. Long pole in the tent items that I still need to get done are the intake manifold for use with the new heads, wiring in the new EFI system (I am moving to an MS3-Pro EFI box), and finishing up the bumpers. Once the intake is done I can get the engine on the dyno, hopefully the weekend of August 6-7. This would give me enough time to get the engine back in the car and make it to the track once or twice before Drag Week.
I'm going to do my best to stay on this schedule, but if history is any guide it will be a challenge to make all this happen in the allotted time. I can feel a last minute thrash coming...
