Head gasket issue, v4 crossflow, what would you try?

[leaky]

I have a jl88mlsea I believe, 1990ish 88 spl, flatback, I just started today after a fresh rebuild. Should have snapped some pics, pretty damn clean one that's unusual to find now days..

Good news is it popped right off and idles smooth, quiet, happy. Bad news was I had this weap, at high idle a little stream, of water shooting up out of the port head gasket, right at the top, near that gasket tab that says "top". Seemed to exit on the block side of the gasket, definitely a gasket leak - it would start with bubbles very defined along the gasket.

BRP gasket 318358, not a knock off or even sierra. Wasn't my best work setting it on (kinda rushed and did it while it was hanging on the crane for install), but was careful and probably did better than most.

First repair attempt, retorqued to 235 inch lbs. It actually slowed the flow to a weep but didn't stop it. Unacceptable, yanked head.

Head is pretty damn flat as verified by laying it on 7/8 aluminum plate i got hanging around. Looks good on the block. Block looks square by similarly playing with smaller pieces of plate.

What I did find was this faintest defect in the sealing surface in that exact area of the block. A darker spot that's probably 2 hairs deep, maybe 1/64 wide, but doesn't even extend the whole height of the sealing surface, like a very minor casting flaw, can't feel it except with a pick like you are lining up rod caps. I'd bet a weeks pay any half ass gasket would seal that for a max of 40 psi. But it didn't.

Options:

1. - very carefully install a new gasket "dry" as it should be..

2. #1 except use some aviation gasket sealer there or some other goo you suggest..

3. Try another head (I got a few but this one honestly is mint), and then #1 or #2?

4th option i guess would be to strip it, ship it out, re-deck head past this defect, but sounds insane .. something like first 3 ideas much preferred.

Thanks in advance!

 

[racerone]

Every head that I take off motors is warped.-----Need to refinish on a piece of glass with emery paper.

 

[leaky]

Every head that I take off motors is warped.-----Need to refinish on a piece of glass with emery paper.

Thanks! How do you go at that as far as attaching the paper to the surface?

What I've done, and just did again for good measure on this head, I use strips of 320 grit straight line sander paper (which is adhesive backed and 3" wide I believe) carefully placed on a perfectly flat surface (I tend to use really thick aluminum plate because I have it). Basically end result is a large patch of sandpaper stuck to a very heavy flat surface. I do figure 8s, reverse direction, check that it sits perfectly flat on the same plate.

I just put that head back on, using aircraft gasket sealer on both sides of the water jacket surfaces of a new gasket. And I put a film for good measure, where the leak was on the block. Was very methodical about the torqing, and later today will recheck results.