Final Engine Compression Ratio?
YR, the numbers I listed is how far the piston sticks out about the bore (.159 - .228)
What YR is asking you to measure is the block's deck relative to the lower flat area on the piston top... the part above the eyebrows. You measure compression height to there, not to the top of the dome.
Clean off all the old head gasket material and scrape the deck area around a piston perfectly clean and smooth. Lay a straight edge across that upper area of the piston, just above the eyebrows. If the piston is above the deck, then use feeler gauges to measure the gap between the deck and straight edge. If the piston is below the deck, then use the feeler gauges to measure the gap from the piston to the straight edge. Let us know what you get and which way it is, and we can figure the compression height pretty closely.
And even if the block has been decked, having that relative distance of piston to deck is all you need. Then we can make a stab at the dome and eyebrow volumes and then get close to SCR. With these engines, a 1 cc error is about 0.1 point in SCR so we can easily get within a half point I'd bet.
BTW, check the depth of the head chamber to the
shallow area. Unmilled open head chambers are typically around .100-.110" there.
