Mocked up the BGM to get a before shot last night.
Then I put it on with the flyside, torqued it steadily down to 11ftlbs, ultra coppered the cylinder base and packer, and installed the head.
Gave it all till tonight to settle down, then checked all the torques, and tried the pressure test again.
Then swore a lot. Same bloody result. No discernible leak at the seals, head or cylinder, but a gauge needle that marches steadily down.
Time to get medieval I got out my car engine leakdown test and wound it down as far as I could, and set it loose, which hit the engine with about 18psi via the spark plug hole.
A discernible hiss could be heard from inside the case. I think it's fair to say I was not well pleased.
So off came the flyside. Compared to the original shot, it's obvious the silicon has been squeezed most of the way around.
And it looks like the cylinder wall was tightened up
So - new plan. I want to know where (if any) the highs and lows are, and if it can be made airtight by any means...
That's going to be a bitch to clean, it's once again torqued down, and when it's dried tomorrow I'll find out if nefarious means will actually seal this sucker.