As a continuation of my last comment on the 24th August, this is what I can now add to this dilemma.
I value all opinions on this forum but PLEASE don't jump in here - refer to the original post and read from there - there are pictures!!
The photo's really give the picture - but the "story update" is as follows:-
I pulled the head (which I REALLY didn't want to do - reassembly as we all know is time consuming and a lot of work)
I had oil on the surfaces of pistons, pistons 1 and 4 are shown, which tbh really I didn't want to see.
I had no oil track marks so to speak on both surfaces of the head gasket, (original plus cometic head gasket are shown)
I pulled piston No.1 thinking "maybe" I had installed pistons wrong way, or rings in upside down - I hadn't. Hone marks in the sleeves still prevalent. I removed and rings and confirmed ring gaps - all within spec.
As previously reported I was achieving 170,180,180,180 psi compression but filled the combustion chambers with petrol "just to see" valve seat status - levels fell to 50% equally over a period of 36 hours but that I am sure was due to evaporation.
I decided to pressurize the exhaust manifold chambers with air and made up an adapter for this purpose - I wanted to see if the chambers would hold air (40psi) or were maybe rapidly discharging air through the valve guides/tappet to sleeve running clearances, (or god forbid, somewhere else) - they were not. I WAS seeing minor leakage around the valve seats which tbh I was not worried about as quite simple valve seats are not designed to seal "backwards" so to speak.
I removed the exhaust valve from No.1 cylinder and there was zero discernable play in the guide and valve stem. (Note valves and guides are new)
I measured tappet (cam follower) to sleeve running clearances on No1 and at 8/10th of a thou - this was well within spec.
Note: I did not in any interrogate in any way the inlet valve side of the head - I have no symptoms giving any areas of concern here. Equally I did not disassemble the whole head, but concentrated on Cylinder No.1; for obvious reasons I was trying to keep disassembly to a minimum.
So..... unless I have missed something, (please chip in if I have), I am going to reassemble everything, finish the whole build and "work" the engine down the motorway. You will note from the history of this topic that I have run this engine since a complete rebuild for maybe a cumulative total of 1 hr - she starts well, high and low idles well, has no excessive crankcase pressure, has a clean exhaust and overall sounds very sweet.
Interestingly, had I had exhaust manifold gaskets that were perfectly sealing on No.1 cylinder - I would not be where I am today as quite simply I would have not been aware of any problem, (which I am now beginning to think doesn't exist). I believe the engine needs running - under load, to bed and settle the piston rings to bore relationship as quite simply, I cannot think of anything else to do.
Correction: My original post quotes Pistons 3 and 4 -
this is incorrect - should have read 1 & 2, with 1 being closest to the timing cover.
