Can my head be saved?

I did a dumb thing and bought a used cylinder head sight-unseen from across the country. It came with some nice cams, which is what I was really interested in, but I had hoped to be able to use the head too. To cut a long story short, can this head be saved?

My gut is no.

are those fissures in the combustion chamber?

smart money says no.

that can be pinned. i saw a video in school about some "new" pinning technique where they drill pilot holes into the crack and then self tapping screwey pins where they overlap. in the video they actually showed a guy pinning a crack that went across the seat, then ground off the part of the pin that stuck out, then resurfaced the head and did a valve job. unfortunatley all i saw was the video and i cant remember the actual name of the technique. to answer your question however, yes it can be saved.

yes, I believe those are all inside the combustion chamber. I think you can see the cylinder outline very faintly at the top of the pic. There are at least two to three dents that breach the cylinder outline, but that picture didn't load (naturally).

and I believe this damage was caused by a piston and associated debris attempting to exit the block.

grimmelshanks wrote: video in school about some "new" pinning technique where they drill pilot holes into the crack

Interesting definition of new.....There were a lot of blocks fixed that way before antifreeze was invented.

it was new when the video was made, hense my use of quotation marks.

fixed the pics, hoping for more input. Some friends have shown me pics of people fixing aluminum heads (the answer is Miata, of course), wondering if there are other opinions out there...

the head is not the best out there, but it has had some work done to it and would be a real time, money, and effort saver if it could be reused for cheap, or mostly-cheap.

That can be fixed. If they are too deep to take off by decking the head (or if you don't want it decked that far), have them welded up and then deck the head flat.

a decent machine shop with a guy that knows how to operate a tig welder can fix that right up. that is one of the good things about aluminum heads vs cast iron.

those are the answers I like to hear :)

since I know nothing of the previous history of this head, how can I tell if it's been decked already? I have the factory shop manual, and it gives various minimums, but does not describe how to measure such things...

Check the combustion size against a known stock head.

Two things:

Did the seller misrepresent the heads, calling it good and you got boned?

Second: I'm confused by the "pinning". I understand it's a technique to stop a crack from getting longer, but I don't see a crack in your photos. The top silvery line across the intake-exhaust valves looks like a build up of carbon, that's the lip or edge I'm seeing; scuff it with a razor and see if it moves. The line below it in the spark plug hole looks like a hair on the lens or the head.

Stress concentrators: Picture two surfaces coming together at a 90 degree angle. Right where they meet is a sharp inside edge. Now picture the same interior angle with a nice radius there. If you yanked the two pieces of material away from each other, which one will fail first; the one with the sharp edge inside or the one with the generous radius?

Those pecker marks from a broken valve bouncing around are stress concentrators, add heat and pressure to the mix and you may have someting going on, maybe not.

I would get a dremmel with a soft white wheel and try to remove or at least "soften" the pecker marks, make them a radii instead of a sharp edge. I would also have the head milled, resurface the area where the head gasket sits and it may remove the pecker marks all together.

If there is a crack in there that I don't see, it can be wekded up by someone that knows what they're doing and then configured to the stock appearance. I believe to TIG it up you would have to slightly heat the head up, TIG it, then anneal - normalize the material to remove stresses induced in the process. Weld it up THEN do all the machining, resurfacing etc.

My experience with aluminum heads is they give a dimension from the centerline of the cam to the head gasket mating surface as a minimum. You can go below that but run the risk of floppy cam and other stuff.

Your original question: Can this head be saved?

Yep. I wouldn't be afraid of it. Talk to someone about Zyglo or Dye Penetrant to locate the cracks, after that it's easy.

Dan

I have had much worse than that repaired on a Mercedes head with complete sucess. Find a competent machine shop and they can fix it right up.

peter wrote: ...My gut is no.

Go with your gut.

If all you're concerned about is the little dents, either have the head resurfaced to take as much as possible, or just clean them up with a file to take the high spots off, and call it a day.

Rebuilding heads is what I do, and I would use that head. That is not a big deal by any means.

Ship the head to zomby woof.

I too do not see cracks, but "pecker marks". I had those inside the combustion chamber of the head off my Nissan truck. I suspect it was a piece of broken piston or piston ring bouncing around in there. I barely smoothed them out and had the head serviced. Its been fine for 30k miles.

Good lord, many a head looks much worse than that one and runs just fine. Hand file the high spots off, or tap them back down (easier to do than you realize). Run the head.

Many heads look much worse after a "good" head job.

Roloc it, have the head milled .010

To know if your head can be fixed, I think you should consult a psychiatrist not an automotive forum populated by cheap gearheads! Really, anything can be fixed. The trick is finding someone with the skills and deciding how much you want to spend. But I agree with zomby, not because I'm an expert, but because I've had heads with similar damage repaired in the past, both by a professional and myself.

I keep reading this as "Can my head be shaved?" It's working for me. :)

DILYSI Dave wrote: I keep reading this as "Can my head be shaved?" It's working for me. :)

Same here... but there is less to shave every day...

zomby woof wrote: If all you're concerned about is the little dents, either have the head resurfaced to take as much as possible, or just clean them up with a file to take the high spots off, and call it a day. Rebuilding heads is what I do, and I would use that head. That is not a big deal by any means.

What he said.

I learn something new every day, thanks everyone!

So I shouldn't worry that those divots are going to create hot-spots that could cause premature ignition or anything like that? I could just run with the head as-is, or shave/smooth it if I like?

And the dings in the lip of the combustion chamber won't cause sealing problems with the block?

And FYI, those lines in the first photo are definitely hairs, not cracks.

After years of work, I've gotten comfortable with suspensions, brakes, and the stuff that hangs off the engine. I'm still a complete noob when it comes to engine internals.

Yes it can be shaved Felpro even makes double thickness gaskets so belt tention and cam timming would stay the same. But like mosto others i'd just hit it with a Scocth lock pad and take off the high spots and run it.