Its worth a shot, I think. As you can see by the picture cleaning is a non issue, its spotless, degreased and easy to access at this point. But I don't think "normal" RTV will do it. When I tried the blue RTV (24hr cure before testing, UV dye and insp light) a very tiny "pimple" appeared @ the leak point (right where the awl point is in the picture above). It grew to about 1/8" over a minute or so, and then popped like a zit. The leak then continued to slowly bleed like a rose thorn prick until the head temp came up, at which time it all but STOPPED! Hence my befuddled and mystified frustration. I'm thinking Devcon catylized epoxy polyurethane or a similar industrial tank patch material. If that doesn't work, I'll let it leak and drive it through the Spring/Summer ,and the heads coming off next winter.
I've never found an application for "blue RTV" where it wasn't a big disappointment. Especially hot oil under pressure. I've cleaned a lot of it's remains out of oil pickup screens. You might have some success with the Devcon (I've used their "Plastic Welder" successfully for a lot of things). JB Weld is a favorite also. Your biggest challenge will likely be movement between the parts during heat cycles (the very thing that seals up the leak when hot). It will likely open up a crack after a while. The popping blister you described indicates that you have significant pressure behind the leak. There is an oil passage between the block and head very near that point (feeds hot oil to the cams) there's apparently a tiny channel that has opened to the outside world (where all hot car fluids hope to one day go). The whole thing looks manageable and could certainly be a lot worse. The Italians have never been very good at "fluid containment".
Really ?? I hadn't noticed ;-) Yes, like I stated earlier, there is not very much gasket and mating surface between that oil feed passage and the outside of the head/block. And that is a feed to the cam journals, not a return, so full oil pressure.
here's a shot of the head and gasket for that area for reference Lou. Image Unavailable, Please Login Image Unavailable, Please Login
If I were going to try anything to stop that leak, I would use aircraft 3204 type B two part sealant or simular (3201,3206, etc.,). http://www.sacskyranch.com/proseal.htm http://www.neelyindustries.com/chemseal.htm http://www.specialtyadhesives.com/flamemaster1.htm I have seen that stuff (3204) do absolutely amazing things. I made wing gap cabin seals for an AeroCommander once, and was facinated with it. I stipled it into fiberglass matting and stuck it onto the metal to close off the area, then built up three layers of matt by stipling the 3204 into it. Once it cured it was like a fabric tire patch. Flexible, but fantastically strong. Its not cheap stuff, probably $50 for a pint, and youll throw 95% of it away trying to seal that little leak, but I cant think of anything else worth trying. Any of the RTV or silicone type sealers wont stick as well, dont have much strength, and arent as oil and heat proof. Clean up the area with MEK and let it dry, then work a bead of the stuff into the head gasket seam as far in both directions as possible, wipe off the excess, let it cure and cross your finger's. You might get lucky. I would even consider working it into a piece of heavy string and working the string into the gap as the string would help make a far stronger seal. Just make sure to follow the mixing instructions to the letter.
Grazie, Signore !! Looking at those pictures and where my little leak is showing up, it seems like if only that adjacent head stud/nut was torqued even close to properly, the other nine could be loose, overtorqued or missing and it wouldn't leak THERE. Hence my belief its a faulty, damaged or eroded gasket or a scratch in the block sealing surface. It's either plug it successfully with high performance patch material, or pull the head.
Thanx once again for the info/links Paul, I'll consider this. The flexability and adhesion properties are certainly impressive, (have to review the heat resistance and tensil strength). There is no "gap". The head, gasket, and block are virtually flush to one another, and the "hole" is at the block face of the gasket and too small to detect visually with a lighted magnifying glass.Took months and UV dye/UV light in a dark garage to pinpoint the little bastard. If I were to use anything to reinforce the patch material it would have to bridge the head, the gasket and the block. Oh well, off to do a sanity check retorque, I'm getting really good at removing and re-installing dizzy's and cam covers! At least I used non setting removable gasket dressing
OK. First, sanity check retorque confirmed I am not crazy I decided to use a Titanium filled high temp epoxy due to it's temp, bonding, elasticity under heat and tensile properties. http://polymericsystems.com/technical-data/pdf/QuikTitaniumTDS(4012-EM07).pdf Did a 24hr cure @ 150 degrees with heat lamp, full 72 hr cure before pressure test. As I (and most others) figured, it still leaks ever so slightly @ the far ends of the "patch" just a miniscual amount, maybe 5% of the original weep. I confirmed this with ultraviolet light and dye, which is still in the system. But, that is 90% better than I had before. I assume it will continue or worsen with time, but I'm good to go until next winter. I will have to pull the head (or whole lump) and do a head gasket replacement then, if I want a totally leak free Ferrari (is that possible?). -L
