Cylinder Head Repair Options

[jeffclark42]

I have a cylinder head from a 6.5 that has cracks in it. It has the typical cracks through 3 of 4 bridges (btwn the valves through the seats). It also has 1 short crack extending out through the valve seat on one of the exhaust valves.

I understand that a sleeve can be inserted to safe guard the cracks in the bridges against coolant leakage (good as new I'm told). What about the radial crack on the exhaust valve seat? Can this be repaired? If so, what are the common techniques and what do you think of the reliabilty afterwards?

Lastly, another option might be to simply replace the head entirely. Is it okay to mix an old head and a new head on the same block, or should I just replace both?

Thanks,

jeff

[john8662]

You've come to the right conclusions on the cracks that are between the valves, fixing them with the sleeve kit. Most of the cracks between the valves end up being cosmetic and never enter the water jacket. The sleeve kit is a great preventative maintenance measure.

The crack that your describing that starts at the exhaust valve and is starting to head accross the surface is a bad crack. Without seeing it, I'd still say that you're best off replacing that head. The only cracks that are acceptable are the short ones between the valves, and the cracks that occur in the pre-combustion chambers (as long as they don't exceed the sealing ring of the gasket).

I don't think you'll have a problem mixing the heads at all. Just take note of the cast number and which precombustion chambers are installed in the heads. Most of the early 6.5's head had the "T" cups installed, where as the latest heads have the Diamond pre-cups, which have a larger opening and a Diamond emblem casted into the surface of the cup. You don't want to mix these.

[redbird2]

The crack you are talking about out across valve seat in the crack of death. I have been buying heads new from Clearwater Cylinder Head with valves install ready to drop on $385.00 plus shipping. We replace 2 or 3 set of head per month I see a lot of these cracks. good luck don't forget to change the headbolts when you put it back togeather.