OK, I'm in need of some guru therapy here. On Athal's advice, I cc'ed the combustion chambers and discovered that they are smaller than I thought.
And in my own defense, this was based on what they should have been from VPD's somewhat incapable hands.

Here's the cold numbers:

Bore = 3.53"
Stroke = 3.1496"
Head Gasket thickness = 0.037" (crushed)
Combustion Chamber = 50 cc
Piston Deck height = -0.021"

By my calculations, this gives me a total compression ratio of 10.6:1.

Jesus, what have I done?

Based on my original expectation of a zero decked engine and my desired combustion ratio of 9.5:1 - VPD screwed up and planed the head too much. If the damn pistons didn't come out of the block, I'd still have 10:1
CR.

OK, so the B20E use to have a 10.5:1 CR from the factory, so I'm in that ballpark, but I've got much tighter squish than the factory did (they were 0.023" down the cylinder - so the "E" head is really thin. In my own haze, this makes my engine better, as keeping the compression in the head and out of the block is better for making more turbulence and better cooling than the stock 10.5:1 would have made.

This is of course, a static CR and doesn't take into account the overlap of the cam etc...

My concern is that my piston running clearance may be a little tight. I've got to double check that head gasket, but my rough calculation (of crush height that is) tells me that the piston is going to be 0.021 - 0.037 = 0.016" from the head. The pistons are much tighter than the Mahle's and with the longer rod (and shorter piston) they don't rock in the bore's - this should be a good thing, but I'm a little worried that this is pushing it for clearance.

Thoughts, comments, soothing words...

I give up...piston #4 was up 0.030...I took the engine apart tonight and exchanged #1 and #4 and then #1 was up 0.030. The other three pistons are up 0.020 (measured with a dial indicator and a straight edge...it's right), as the block is not stepped, I now suspect that the crank is screwed. It was reconditioned (before I got it) and has had 0.010 ground off the big end journals.

I think Greg may have a spare 8 bolt crank sitting around...

This engine build sucks my hind end.

Pistons are going back to get 0.020 taken off them.

NOOOOOOOOOOOOOOOOO!!!!!!

Indeed. This sucks.

But I do have a spare crank, or two.

Wow, I just woke up and my fingers aren't working very well, so getting thoughts to screen is tough.

If #4 was .030" and when you switched it to #1, #1 became .030", it's that rod/piston that's too long. The throws on #1 and #4 journals are the same, so the crank should be okay. The .020" measurement went with the original #1 piston to the #4 hole when you swapped them, backing this up.

If you kept the .020 measurements and went with a stock Mahle head gasket, assuming the B20 head gaskets are 1.25mm like the B21/B23 gaskets are, you'd have .029" of piston/head clearance, which is still tighter than many folk would run but DEFINITELY workable considering your pistons/rods. That one piston/rod combo would be at .019", a bit too tight, but then you would just have to skim the one piston to get it the same as the rest.

As far as the 10.6:1 CR, it's a bit high for an iron head engine. You'd be running 92-94 octane all the time, for sure, and might still have to dial out some distributor. Shoot, with all the custom stuff you've got going on, a distributor recurve is probably in the works for you anyway. I doubt seriously that the B20E actually has 10.5:1 compression ratio... have you ever measured it? I suspect that most manufacturers use this number as a subliminal selling point to the tech-heads, and they "rate" it based on the actual compression ratio plus a bunch of carbon buildup. I KNOW Volkswagen does it this way, as the Digifant 1.8 litre engines were "rated" at 10:1 but the CR was actually in the low 9s with a clean engine. Anyway, you can fall back on the dynamic CR thing if you want to, but I only see that lowering the cranking compression. At all points after the engine "comes on cam" the actually BMEP will be higher.

Going back to your original plan, shaving .010" off three pistons and .020" off the fourth would give you .027" piston-head clearance, which is mighty fine, and would drop CR to 10.3:1.

That's where I would go.

all the pistons and rods should be identical no? Well, of course they *should* but are they actually? Are JVAB's thingies not as "sooper bitchin" as advertised? Just curious as to where the discrepancy lies, because it's not in the crank as matt pointed out.

All the rods and pistons are the same...I measured them, sorry I wasn't clear, when I switched #1 and #4 the taller piston became #1 in #4's position - ergo my assumption that the crank is in error (that and the fact that it had been reground 0.010).

The head gasket is 0.040 and I'm going to have Vanlandingham knock off 0.016 to give me 0.004 above the block for a 0.033 squish (gasket is 0.040 uncompressed) and 10:1 static compression. I have no way of measuring the dynamic compression without everything in place (and I've never done it).

I want to make sure that everything is OK and as perfect as it can be so I won't be shaving the one piston, that would alter the weight and I don't want that.

Does this sound reasonable? I know it's overkill, but Jesus...what isn't on this engine. I'm still in shock that it happened, but not surprised in the least. This build has been making my life difficult for a couple of years, what's another month.

By the time I've got it built, I'm going to want to put that friggin whiteblock into this car and be done with it.

If you're using another crank, I assume it'll need to be ground for new bearings, can't you use offset grind a bit to drop the pistons down?

We'll have a look at the crank tonight...I suspect all it will need is a polish and it will be good to go. At this point I'd rather not have to trust someone to offset grind the crank correctly - but it is a good idea. I'll give it some thought.

I've got an 8-bolt crank sitting here too...

Regarding compression, I put a .030" HG on my 940 with pistons that were originally 8-9 thou out of the hole each. I advanced the camshaft timing a hair over 4 degrees. I gained a little over a .5 points in SCR and can run 12psi on regular gas with a T-cam where I could only run 9 before.

Nothing hits the head with stock everything within the 6K rev limit.

ASSuming your piston-wall clearance isn't pretty wide with the forged JVAB slugs, you should have less rod stretch than factory (I say this having absolutely NO idea what everything weighs and how much your rods stretch compared to stock), and less piston rock than the offset pin stock slugs.

I think your squish should negate the increase in compression more or less fine, though I wouldn't be shocked if you have to run premium fuel with the stock camshaft head and distributor (no idea what you have).

The B20E I CCed a long time ago had an SCR of ~9.8:1 and could ping on regular fuel that was available as they were phasing nicer premium leaded fuels out in oregon in the latter 90s. Maybe that is why I am partially insane...first learning how to work on cars that burned leaded gas...

Well, we got the B21FT crank pulled and aside from machining a little off the snout, it is the same as the B20. It needs to be ground as it is about 4 thou too small, but it is warn round (weird). So I'll get the machining done and get the crank ground and rebalanced.

When we installed the crank with the old rod and main bearings, the pistons were out of the holes, 0.017 plus or minus 1 thou front to back. I'm sure this is in the warn bearings and the crank wear...as the new bearings on the old crank did yield consistent measurements on 3 of the 4 pistons.

So it was the crank...how crazy is that. My machine shop guy maintains that is is virtually impossible to grind a crank incorrectly, as once you set the machine up, it works. I don't know, but that's how it has all shaken out.

Yeah, okay, now I understand what you were saying. #4 was always the one out of the hole .010" further than the rest, no matter the rod/piston combo. It wasn't clear. My thought was that the one was longer, so you'd cut it down and rebalance everything.

Why on earth wouldn't you take Dale's marine crank rather than do all that extra machining to the B21 crank? I suppose "it's there" and "gas money" are two motivators...

Why send the pistons/rods back to Seattle, when you can get them done locally? To prove a point?

The B21 crank reasoning is as you state (and it is only the snout section and a key...shouldn't be that costly other than the regrind), and my machinist won't touch the pistons as they don't have a piston vice to turn them down, so they go back to Seattle.

About the only other thing I can think of is my depression caused by this bloody engine.

Just wait 'till you have to rebuild it 4 times in 2000 km, THEN talk to me about depression!

Fair enough...but try waiting almost 3 years to finish one engine.