New Rebuilt Head Cracked- Run it?

[twentyeight]

I bought a rebuilt head from a reputable vendor on the site. The head that showed up was obviously rebuilt and looks beautiful, but it's unfortunately cracked from all four injector nozzle holes to the intake valves. I've emailed that vendor but I've yet to hear back.

I've read as much as I can find about cracked diesel heads and found that PD and IDI heads are prone to cracking. I've also read Frank06's theory of how 1Z/AHU head cracks of this nature happen (over-torquing injector hold downs).

What I haven't read is whether or not this is considered acceptable for 1Z/AHU heads. If I'm going to get 100k out of this head I don't like it but I don't care. If it's closer to 10k I care very much.

This is probably the worst one, but they're all cracked to some degree. Click to enlarge.

 

[Ol'Rattler]

Call Franko6 and ask his advise and follow it. My thought would be you should send the head back to the rebuilder.

 

[Abacus]

I'd definitely give Frank a shout about this.

Perhaps it's just parallax error, but the injector hole looks closer to one valve than the other. I'm wondering if that's normal, the result of the rebuild, or from some previous mechanical event.

 

[twentyeight]

I threw a cam and lifters in it and to inspect the valve seats and it looks like they're not cracked. It's pretty difficult to get a good picture of the inside of the valve seat, but I tried:



The injector bore isn't cracked through either.

I also heard back from the vendor who told me it's normal (and that PD heads are worse) and not to worry.

 

[tripl-e]

I suppose the vendor's response should answer the question but I'm still leary. The valve seat is an interference fit in the head casting and depends on its proper fit for both mechanical retention and heat transfer cooling. The length of the visible crack looks similar to the depth of the valve seat which is also worrisome.

Frank06 is the knowledgeable source.

 

[KLXD]

How come I can't see the pichers? No link, no nothin.

 

[WestVa304]

How come I can't see the pichers? No link, no nothin.

Maybe your software needs updated? They show up fine on my phone and computer.

 

[twentyeight]

No idea why they wouldn't be visible in the thread. See if they show up here: http://andrewclink.com/projects/thebus/resources/cracked-head

I'm not terribly comfortable with the situation, either, but it is what it is. Since it's not cracked through the valve seat and I can torque the injector hold downs properly I'm going to run it and hope for the best. None of the plausible failure modes I can think of result in further engine damage— just reduced efficiency, poor running, and a sad owner.

 

[Abacus]

Did you contact Frank about it? It'd be worth a call.