Well, it has been a fun summer with the aluminum block Valiant but the oil level starting rising and the oil stuck to the valve cover is foamy tan. I've been losing water and wondering where it was going. Now it has become pretty obvious. I've changed the oil and I am going to try some stop leak in the radiator but I doubt that will help things. I need to do a compression test but I have a feeling the problem is in cylinder #5 where there was some corrosion at the top of the cylinder. There isn't much sealing surface on the top of these blocks.

Any word on new head gasket technology and availability? A new copper gasket is $150 anyway, if Kanter Auto still has them. I guess I'll be looking for a good ole' iron block this fall, just in case a new gasket doesn't last.

Next time you have the head off the Alm. block you will have to fix the corrosion with some high temp epoxy.

Just for another "data point" was the block's deck resurfaced along with the head? I find that the only way to get successful (long term) head gasket sealing with the Alm. SL6 is to have both surfaces remachined with a good (fine) finish.
DD

Whoah, hold it, don't use that radiator "stop leak" stuff. You'll cause a lot more problems than you'll solve!

I agree with you, you are probably losing coolant into the crankcase. See Doctor Dodge's comments regarding getting the gasket to seal. Not sure what you mean with regards to a copper gasket from Kanter's; as far as I know the only option for aluminum-engine head gaskets are the original-type copper/asbestos laminated ones (are those the ones you're talking about?).

Perhaps we need to push forward with Cometic!

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Too many people who were born on third base actually believe they've hit a triple.

The gasket I refer to is the original type copper and laminate. I'll take your advice on the "stop-leak" I hate that stuff anyway.

The head was re-surfaced but the deck was re-surfaced by me with a piece of 80 grit sandpaper wrapped around a piece of steel and pushed in one direction across the length of the block 20 or so times (per my machinists instructions).

That epoxy just might be the ticket. Would PC-7 work? I'm thinking I would let it set up some and then torque the head down and not start it for a couple of days. I'm wide open to suggestions.

Don't like this idea at all. Way too easy to get a wavy/uneven surface! Proper resurfacing is a precision operation.
You probably want to do this once and do it right, so don't futz with hardware-store kid stuff get the industrial pro stuff Belzona makes. (Actually, PC7 is a great product, but doesn't have the metallic-adhesion or temperature-resistance characteristics you need for this job).
Oops, no. The idea isn't to use epoxy as a gasket sealant (yikes!). The idea is to apply the epoxy repair compound to corroded and worn-down areas of the sealing surfaces, let it set up, then have the sealing surface machined nice and flat. If you will take the time to search, you will probably find a machine shop able and willing to machine the block surface separately from the cylinder top surfaces, so that the cylinder tops stand a couple of thousandths proud of the block surface. This can help to ensure a good and durable combustion seal. When you install the new gasket, you will want to apply a carefully-chosen sealant compound to help the ancillaries (oil and water passages) seal. I recommend multiple thin coats of spray Copper-Cote, with some daub-on Copper-Cote on the block and head themselves. Doctor Dodge probably has some "tricks" up his sleeve for getting these engines to seal up, and doing what he says is a good idea, 'cause he's built a lot of these engines!

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Wouldn't I need to have the cylinder top decked where epoxy was applied?
If so, would you mill the complete block deck and THEN go back a take another thousand or two off everything but the cylinder tops?

So, I'll have to pull the motor, disassemble it down to the bare block and take it to a machine shop after I apply the Belzona epoxy (if I can get it)?

Sounds like this is the reality to get this engine to last a while. Thanks for all your help.

Well, the way I see it, you'd probably want to first grit-blast the deck (mask off the cylinder and lifter bores!) to clean and roughen the surface so as to give the epoxy maximum "tooth", then apply epoxy to the whole deck surface, then have the whole deck milled, then go back and take another thousandth or two off everything but the cylinder tops, but check this with Doug! I'm just speaking from theory here.
'Fraid so

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I think my engine is OK. I re-torqued the head bolts. It required a quarter turn of the wrench to get back to 65 ft. lbs. on all bolts. I knew they weren't quite up to spec after I had run the engine through a few cycles of warming up and cooling down, but I was leery of cranking the bolts down because of the aluminum block. After this problem came up, I had nothing to lose. I did a compression test with engine warm, throttle wide open and got 152, 160, 145, 160, 170, and 155 (#1 through #6). I changed the oil and filter twice now and changed the antifreeze and added a half bottle of bar's leak ( I know, but I did it). I drove the car about 100 miles at different times over the weekend and the oil level remains steady and looks normal. I haven't flogged it, though.

Seems like weird science to me too. I think the leakage was on the copper side of the gasket. The head was re-conditioned at a machine shop so that composite side of the gasket should be flat. Since the block side is copper I'm guessing that the gasket didn't break, it just lifted. BTW, I backed the valve lash off some before I re-torqued the head. I ordered the new gasket set, just in case.

Hope that works. On iron blocks, I always torque my head bolts to more like 85ft-lbs.

Retorquing was a good idea, especially with an older gasket design.

Best of luck,

Lou

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Home of Slant6-powered fun machines since 1988

Good move on the retorque...let's hope it holds.

On the subject of corrosion repair on the Alm block SL6, do as Dan suggested.
-Disassemble engine and grit blast the corrosion areas.
-Use a good quality, metal filled, high temp epoxy and build it up, out and over the head gasket sealing surface.
-Pull the dowl pins and resurface the entire block deck, this will machine the epoxy level to the block deck and get everything flat.
-To get the bores "proud" I block sand the outer alm. block rails that hold all the head bolt bosses. I have a 3 ft long 'dead flat' sanding board I use for this job.
DD

Great advice from the pro's. I'm keeping a close eye on the issue and will keep you posted. Maybe I'll do another retorquing and bump it up to 70 ft. lbs. I would hope the longer head bolts of the aluminum block engine can handle it.

You all are killing me with the performance builds-ups going on here. I think I'm gonna get another junker 225 iron block engine and, for now, have it on hand.