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Hi Steve- You're right- I went back and took another look at my project photos, and at TDC, the piston never exhibits protrusion- it is down, looks like around 1/2".
And guys- I understand compression height, displacement, compression ratio, and piston ring theory very, very well- I bought a hardbound copy of Taylor's "The Internal Combustion Engine in Theory and Practice, 2nd Edition" when I was in high-school, read it cover-to-cover and bluprinted a few engines prior to engineering school. Compression ratio is a function of displacement over TDC total chambered volume. This volume includes volume left unoccupied by the 'dish', as well as unswept area at the top of the cylinder... even the cavity area within the spark-plug insulator and a wee bit'a space around that top ring.
Panky- What John refers to on Page 50 only applies when you're comparing the compression ring's position between two identical pistons, and if you do the math, you'll find that the change of compression characteristic with respect to setback distance only has a significant effect when you have very high CR and very little quench volume. John didn't overlook this in the article, Page 49 states it quite clearly. In short, when you're dealing with a total chamber volume of 100cc, having 0.031cc of ring land volume, vs. 0.029cc, the net change in compression ratio is three places in from the decimal.
Finally, if you look at Page 50, directly above where you referenced, the image caption explains why one would NOT want to relocate the ring higher- durability.
All I'm trying to do, is determine, out of all the 'stuff' advertised out there, what is imported (and for me, undesired), and where non-dished pistons are offered, will the WC gasoline stock 5:1 compression ratio wind up being 7.25:1, or what. So far, of what I've seen, NOBODY advertises the point of origin, or the resulting CR WILL be.
Perhaps I'm being a bit too 'protective' of my project, but there's a plethora of parts being shipped in from southeast Asia, and I have no intention of putting such things inside this old girl. Melling is about a 40 minute drive from my doorstep, so if I buy everything individually, I'll drive up there and tour the plant when I pick up sleeves. Pistons are a different story- I haven't seen ANY places that advertise making replacement AC power-crater pistons, and I suspect that if they WERE, they'd likely be imported. Frankly, if domestically-made quality replacements aren't available, I'd rather chuck my pistons in the 10EE and turn 'em to round and re-cut the ring lands, have a new set of rings MADE, and take 'em to Melling to have a set of undersized sleeves made-to-suit, but I have a sneaking suspicion I'm not the first guy to be doing a WC.
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I think we all have the same concerns Dave.. probalby 90% of the guys on this page, if they were rebulding a motor, would like to use USA parts. Thye would also like to raise the compression from the original 5 or 6 :1 to 7.5 or 8 :1 just to get a couple extra HP. Boring the motor .030 over is not going to make any HP to speak of. What you really want is dependability... That being said, there is nothing wrong with Asian parts if your dealing with a good dealer who has had good luck with his parts. Your putting your faith in the dealer... Sounds like you know what you want, but might not be available.. I think the overseas pistons are probalby o.k. Most of the liners are=o.k.... what you really got to do is measure and make sure they are made to spec.. YOu can buy Hasting Piston rings in ANT size you want for ANY motor, on their site . You might go that route. I remember a couple weeks ago someone bought a new ikit and then found out the bores were .015 oversize and not round... thats were your dealer can be helpful..
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