Aluminum head repair, radical idea?

I have 440-1 heads that have been milled to a point they are possibly too thin for very high compression or any power adder. So what to do if i want to strengthen them?
Here is my radical idea. A sheet of the right grade of aluminum could be water jet cut to the dimensions of a head gasket, leaving metal in the closed portion of each chamber. All bolt holes, chambers and water passages would be enlarged by enough to allow a heavy weld bead to be used to bond the sheet of aluminum. End result would be a heavy bead of weld would be supporting the fire ring areas, all bolt holes and water passages. If needed, plug welds could be used to add strength anywhere it may be needed, like in the chamber area
After welding each hole starting from the center and moving out, the head could now be decked to create a flat deck surface again.
I have access to a waterjet, possibly through a relative. The sheet could be .62 to . 125 thick and be milled back to .050 or . 100 . I can open up the bolt holes and other passages to provide room for the welds. I could also do the welding with a spool gun. Clean up chambers and holes, then send out for milling.
Anyone done anything similar to this? It would save a very good set of heads if successful. Replacement cost ( versus repair) of the castings and port work would be more than $4,000.00 cost of this repair,
Under $500. Ok welders and machinists, lets hear your thoughts!

I'm not a welder nor a machinist but good Lord, how much have you decked those heads?

I would just weld the whole face and mill.

not sure, had a gasket failure at 15/1 compression.

That might be a lot easier! I was worried about warping, and also about strength after welding.
I talked to the shop yhat does my machine work and head repair. His comment was it would soften the casting too much and the seats may not stay in. Soooi, thats out.

I know you run alcohol, ... is it possible to fill the heads ???

It's not going to strengthen the head any if .100 or less

Maybe sell the heads to someone who could use them "as is" and get another set done properly if the math works out anywhere close, I mean if you can sell them for $3000 and buy replacements with the proper thickness for $4000 then it only cost $1000 to "fix" them the best possible way VS what your talking about, and don't forget welding them like that will mess with the valve seats and they should be reground at minimum but they will loosen up and shift during the process and really should be replaced.

I love yankee engineering my stuff but I think this is a bad idea on $4000 heads

O-ring the cylinder and add the spacer with a copper gasket the thickness you need. Compression is n the cylinder not the deck face. Do you think it’s moving or flexing? Studs should cure the problem

Excellent idea. I would just have to figure a warm up routine and tow the car.

Cometic gaskets and studs were in use. The head failed first. I had a post put in and welded.

Filling the heads is an idea.

Going rounds might suck

Hey Greg, What about low temp aluminum brazing? I have 2 sets of Dart Pro 1 aluminum heads on a cigarette boat with a pair of 588 ci BBC's . They were very corroded around the water ports at the head gaskets going into the blocks (both engines). I got some low temp aluminum rods that you can use propane or mapp gas (I used acetylene torch since I had) and brazed the corroded ports back up and minor milled the decks.


It worked great as it does not overheat the heads like tig/mig would, and there are claims it is a little harder and may not corrode as bad as original aluminum did (in my salt water application). I will see next time I take apart to freshen them up.

These rods (not harbor freight type aluminum low temp rods or other manufacturers) worked great .... they are widely used in aerospace, automotive manufacturers, Cummings, US Army, Harley Davidson, and tons of other well known companies..... and even NASA !

The ones I used are from https://www.aluminumrepair.com/ With their HTS-2000 rods.

If you read the process to use, it is fairly easy with a little light practice first, does not need extreme cleaning of oils and impurities like tigging does. There are a lot of good videos on the site to show real use of them.

I don't know if you want to go through the process to accomplish what you want to do, but it is definately an option.

Randy

Randy, thanks for your input. Those rods sound like the best option so far. If i choose to try and build the heads up, i will test my skills on a junk head to start with them.

Welding the entire surface of the head will absolutely shrink the head. You’ll have to machine every surface of the heads. Even welding a plate on won’t so much. If you can’t use them, sell them.

tin can swap meet rods? Shrinkage? What do you think a place like Brodix or the like uses. Extreme extensive welding in the deck area is done every day. What is the issue here? Is it that you think that the deck surface is giving way under pressure? Does it show on a straight edge? There is the weak spot fill and mill. Cylinder pressures under combustion is the issue . Mechanical ratio isn't the issue. A pinging 8.5 to one engine has more pressure than what you are dealing with. Is there warpage showing on the head?

Not trying to be a WA here but if you had a gasket failure, why do you think it is due to excessive milling? Especially when you are unsure of the amount of milling? What I'm getting at is that if there is some other reason for the gasket failure, drastically reworking the heads may not solve the problem.

Could you get a reasonable guess by doing the old trick of measuring the thickness of a lower head bolt boss and comparing it to a virgin head?

A comparison was made from my heads to others thickness. The area where the gasket failed was sunk slightly on the head. Not burned, just pressed in a bit. One thought is, is it possible there was air trapped in the head, allowing it to get pretty hot? That would weaken the head, maybe being rhe cause of the failure?

Hmm. I really doubt that absence of cooling overheated a small part of the head. The comparison I was talking of was between 440-1 heads. Have you talked to Indy to get a dimension on a head bolt boss? I still think you should nail down just how much has been taken off the face. Otherwise I fear you may end up chasing your tail.

Thought, according to Mancini, the as delivered chamber cc is 75 cc and can be milled to 62 cc. What is your chamber cc? This may give you an idea of where you are.

I just dug out an old Car Craft / Elapsed Times /Fall /2013 issue.One of the articles was about Reher Morrison's '82 Camaro with their then state of the art factory highly modified/ welded heads. Being the pioneers that they were they went in deep.They welded so much on those heads that they couldn't make the whole race at Indy with out doing a valve job before the final against Glidden. Some cylinders were leaking more than 50%!Rain came just before the final round postponing it til the following day giving them time to fix the heads ,as they never would have been able to beat Glidden without it. Alot of things to consider when doing that much welding ,for durability. It is an interesting read, though. Good luck whatever way you go. Bill

At the bolt area, below the exhaust ports my heads are now . 868 thick and . 862 thick. Chambers have been opened up some for a 4.50 bore, plus other work. Different valve sizes from original. It is hard to know how much the chamber volumes were increased doing that. I think the best plan is to just use them on a large low compression deal. I could build a 604 with 11/1 compression by reusing the block , pistons etc from the 550 combo with a 4.75 crank.