6.0 & 6.4 Ford Diesel Cylinder Heads
Ford 6.0 and 6.4 Powerstroke Diesel Cracked Cylinder Heads
We’ll make your 6.0 and 6.4 Ford diesel cylinder heads as bullet proof as we can. The following is what Ford says about your cracked heads:
Copied from AERA Tech Bulletin 2532:
‘Ford’s comment; NOTE: The cylinder head chamber area may exhibit very small “surface fissures” or “micro-cracks” during the Magnaflux process. These fissures or micro-cracks are typically located between the glow plug and the valve seats. They DO NOT extend into the coolant jacket and will not cause coolant loss or cooling system over pressurization. The presence of surface fissures or micro-cracks is not cause for replacement of the cylinder head.’
I don’t know about you but I wouldn’t feel good about putting diesel heads back on my truck KNOWING they are cracked just because Ford say it’s O.K. It is true that most of the heads we see, the cracks have not gone into the cooling system……….yet. Cracks in cast iron cylinder heads grow, period. I also agree that the progression of these cracks, sometimes called propagation, will take quite a while UNLESS, it overheats again. Let me show you what happens.
Here is a picture of the typical glow plug hole to exhaust seat “micro-crack” as Ford calls it. The hole in the center is the injector hole, some of you already know this, and the small one at 4:00 below and to the right is the glow plug hole. If you agree that cracks grow, this won’t stay this small forever.
- Glow Plug Fracture
Below is a picture of a typical seat fracture. If you’re not familiar with these type of seat they integrally cast meaning they are just part of the cast iron head. You cast the cylinder head and cut these out of the iron and you have a seat. The problem is the seat is only as strong as the cast iron. Ford and everyone else for that matter says either flame harden, induction harden etc. but that is just a surface treatment. Detroit, Cummins, Caterpillar and all the rest of the heavy duty diesels install heavy duty valve seat inserts, typically a Stellite or Hi-Chrome alloy, sometimes non-magnetic. The seats we install in these heads are a Stellite Hi-Chrome alloy seat. This is what I’ll show next.
The next picture is cast iron seat removed and counter bored for the replacement seat.
What is hard to tell from the picture is the crack is all gone.
If the valve seat is cracked beyond what we can cut out for a replacement seat, that is not a good repair by this method for the reasons mentioned earlier, cracks grow.
Below is the unfinished seat. We leave them slightly high so we can cut the valve recess to approximately .005” from finished depth.
Below is a picture of the seat that has been 3 angle cut (30, 37 1/2 and 60 degrees) to .005” from finished valve head recess.
Here is the cylinder head with the seat work done.
All that’s left is final clean, wash and assembly.
We have now made these heads as bullet proof as possible. I don’t even think my ex-wife could kill these. If you have any questions about EGR cooler bypass, EGR valve bypass, please call.