Not so much worried, mate. Obviously, I don't want to get it wrong but want to learn from this and hopefully get it as close to right as possible. Call it youthful curiosity
No worries , neilly and if I'm doing something daft I'd rather you said. That was more me referring to my inexperience and knowing I could well be doing something wrong. If I thought you were being unreasonable I would politely tell you
Yes, James that what I was doing last night.
Second set of measurements and I obviously got something wrong with No3 last night.
I've used two methods tonight.
Zero'd on a spirit level like this to get a generic reading across the piston surface, as I think raywin was suggesting.
View attachment 122307
Then I did one reference to the head and took a reading either side of the piston hole (timing end & clutch end) like this.
View attachment 122308
This is what I got
Piston 1 Piston 2 Piston 3 Piston 4
spirit level 0.65 0.67 0.69 0.68
two readings 0.61 0.62 0.68 0.72 0.67 0.77 0.71 0.63
Don't know how I got those readings for piston 3 last night other than my back was aching from being bent over cleaning the big end bolt threads and nuts and it was late!
That's in to the three hole range, with a bit to spare on the three hole gasket. However, the stand down on the valves were slightly over tolerance (I'll have to go back and check exactly) So, the three hole should be just about right.