Headgasket install on a 2000 4.3 Mercruiser: Dry or wet?

[Porschesolutions]

After a year of chasing issues, I finally found my FINAL problem: a warped head. It started with:
1. new-to-me boat purchase, ran rough & rich, thought it was tuning.
2. ran well at my house with fresh gas, but not on the water. Had to be towed in...wouldn't idle or plane.
3. rebuilt the carb, set the mixture at my house, still no good.
4. compression test on found 2 dead cylinders: 3 & 5. Removal of Valve cover found corroded/broken valve springs.
5. replaced those valve springs, compression back up. Boat still wouldn't idle.
6. Found bad ignition wires, distributor installed incorrectly.
7. Set timing, timing was set to 18 degrees ATDC (yes).
8. winterized boat, changed oil
9. Took boat out in February to tune, started behaving better and worked my way up to 38mph, but then wouldn't idle again, retired before we needed to be towed in.
10. found a little water in my oil, enough to dig in again.
11. found one water shutter "torched".
12. Found #6 had no compression.
13. Found broken valve springs on 4 & 6, so pulled heads. Found no cracks or obvious leaks, had intake, heads, wet-manifolds pressure-tested & fluxed. 1-3-5 head came back warped at #3, so had it decked to restore sealing surface.
14. All valves were good, so re-lapped them, installed fresh seals, bought all Marine (Mercruiser, Quicksilver, or Sierra) gaskets & will install the heads tonight.

Can't definitively find whether or not the new Quicksilver head gaskets should be coated or not, esp. where it #3 was leaking prior.

 

[kenny nunez]

If there is no printing on the gaskets warning to not use sealer then a good way to seal them is by spraying them with Chrome aluminum spray paint, you want to mount them while the paint is still wet and torque them down right away. I learned this trick from an old engine machinist. The paint soaks into any imperfections and seals them up. Just hope you do not have to remove the head again because once the paint dries you could remove the head bolts and not get a leak.

 

[porscheguy]

section 3a, page 43, of WSM # 25, when installing ribbed stainless steel head head gaskets apply a THIN coating of quicksilver perfect seal to both sides of gasket. Don’t use too much or it may not seal properly and cause more damage. DO NOT use sealer on graphite composition head gaskets. From the pic it looks like you’re using the graphite type.

 

[Porschesolutions]

yes just didnt know if it was painted/coated Stainless or graphite. It's too hot here to try the paint method though I've heard of that. My gaskets came off dry, but one was leaking, but was the warped head & not a poor gasket.

 

[greno]

Did you install new valve guide seals? Those start leaking and then too much heat gets to the valve springs making them brittle until they finally break. 4.3L seem to have this problem.

 

[Porschesolutions]

Yes new valve stem seals and new springs too- mine were corroded from water infiltration

 

[Bondo]

Ayuh,..... Ya had the head resurfaced, Whatabout the Block,..??

Has it been cleaned, 'n checked for flatness, 'n finish,..??