Is there an epoxy strong enough to cover a divot in the block deck?

[Joe-JDC]

I am reworking my 2019 EMC 303 CI Y Block, and the heads I am going to install have larger intake valves which just kiss the cylinder wall at my camshaft lift.  There are evidence marks where the previous heads had just kissed the cylinders walls, but the valves show no sign of wear or metal transfer, bent, or any issues.  There is not any evidence on the valves, so I am not sure the last set of heads were the culprit.  We had three sets of heads we tested, so it may have been one of the other heads that the valves touched the cylinder wall.  Anyway, I am cutting a bit more clearance on the cylinder edge, and my burr jumped and nicked the deck.  Not bad, but ugly enough to warrant some concern.  The nick in right between two cylinders and where the head gasket is metal at that point.  I would feel better if there was something to apply to the divot and sand it level with the rest of the deck without having to completely disassemble the shortblock and get the decks cut enough to remove the imperfections.  Is there something any of you have used with success in such a situation?  A new gasket may seal it with copper gasket spray and re-torquing, but I am a bit hesitant at this point.  Ideas?  Thanks, Joe-JDC

[frnkeore]

Epoxy seems to soft to do the job. The only thing I can think of to do, is use low temp silver solder. They make many different types of silver solder.

A picture would be helpful.

[jayb]

Epoxy won't hold up to the combustion heat by itself, I don't think.  Could you maybe take a thin copper wire, tap it into the cut, and let the head gasket crush it when the head is torqued?  Outside of that, the only thing I can think of is O-ring that cylinder, or cut the deck.

[kraut61]

Belzona 1111, If you know anyone who works at a petrochemical plant they may have access to a small amount you need instead purchasing minimal amount.
Or Belzona 1511 if you think higher temp product is needed

[Joe-JDC]

JB cold weld has a 200* higher working temperature than Belzona 1511 after talking with a representative.  I am at the proverbial crossing point where I tear it completely down and mill the deck, boil out the water passages again, do a half fill of the block, hone with torque plate, and new ring package.  A simple slip of the grinder, and it becomes a nightmare of sorts.  While I think the gasket may seal just fine, I will have a doubt every time the engine starts.  Thanks for the replies.  Joe-JDC

[Rory428]

About 12 years ago, a buddy had a head gasket fail on his 351W powered 67 Fairlane bracket race car. When he pulled the heads off, there was a "ditch" about 1/4" deep between 2 cylinders, and since he had towed 12 hours to attend this race, he wanted to at least try to patch it up. He bought some JB Weld, and used the epoxy to fill in the groove, and filed it down with a flat file. I figured the JB Weld would get burnt out again on the first pass, but much to my surprise, he made about 6 more passes like that, and then took the car back home. He had planned on replacing the block after he got home, but then decided to see how long it would stay together. Well, he ran that patched up block for 2 more years, until he decided to build a 408 cube stroker engine,using a new block. I never would have believed the JB Weld would have worked that well, but it did. Joe, sounds like your damage is much less severe, so I would give the JB Weld a shot.

[Joe-JDC]

That is an interesting answer.  I had a friend say the same thing about using JB Weld.  Joe-JDC

[blykins]

How deep is it, Joe?

[Joe-JDC]

I can't measure it with a caliper.  It is too small.  It looks worse than it probably is.  I just hate to make a mistake with a die grinder, but it is right where the gasket ring will compress and that is the issue to me.  JB Weld has a new product that is temperature resistant to 1000* and pressure tested to 5250 psi.  It might give that a try.  If it doesn't work, then I will start from scratch and do a complete rebuild.  Joe-JDC

[galaxiex]

Had a late 80's 1.6L 4 cyl Ford Escort (remember those?) had a "burn thru" on the head between the 2 center cylinders.
Divot in the head was at least 1/8 inch deep and about 1/2 inch long.
Patched it with JB Weld and it lasted 2 years of daily driving before finally burning thru again.

[driveamerican]

I shouldn't admit this but I have used JB weld on the deck of an 855 Cummins because it was so beat up the head gasket wouldn't seal it ran the season until we could get it decked and counter bores cut. Mark.

[AlanCasida]

I had a 428CJ head (swap meet item) that had a dented spot between two combustion chamber. It either got it from riding in a trailer pushed against the corner of another head or maybe something was dropped on it. Anyway, it ran clear across the two combustion chambers at the narrowest point . I stippled the area with a pin punch then brazed it. It has held just fine. 

[jayb]

I hadn't thought about brazing, sounds like an excellent solution.

[My427stang]

Brazing a good option, but it'd take a lot of heat there and require machining. 

You could Dykem and torque it and see what it leaves for an imprint, may not be an issue at all.  Depending on the gasket, may not even be an issue reusing.

Maybe at that point you buy a custom gasket with a different bore size to get away from the divot

If losing sleep, I'd disassemble and cut the deck.

[frnkeore]

I hadn't thought about brazing, sounds like an excellent solution.

If considering brazing, silver solder is a better option. Maybe the word solder doesn't sound like it's strong but, if you check into it, it's more like brazing but much stronger and can be done at lower temps. You can get alloys that flow, rather than bead and alloys that are as strong or stronger that 4140.

The alloy that they use in "furnace brazing" is a silver solder alloy.