Engine/Transmission (1994 - 1998) "Good" cylinder head...

[Rhondasway]

Okay, I've heard the term "good cylinder head" vs. "not so good head" for our trucks. Is this a myth? If not, what exactly does it mean, and how does one tell if one has the good head?

 

[Andy Redmond]

A good head would mean no cracks in the seats, injector bores etc. and ability to deck the head and it be in spec for being flat and not warped. Early 12v's were worse about this than later models? Although lately I've seen several low and high mileage 96-97's that had cracks in the seats after the valves were removed and the head was magnafluxed (head gasket replacement was cause for head removal / inspection). The better head gaskets are the "marine" version.



Some don't like to repair or replace the seats and insist "a proper repair" is a new head or a used one that doesn't have cracks in the valve seats (inserts in head).



The 24v guys worry about the casting number on their blocks "53"?



Does this help?



I have some digital photos of a head with cracks in the seats. . maybe I'll try and see if it can be posted.



Andy

 

[krs]

"Good" vs. "Bad" cylinder Heads are no myth. There's good and bad anything.

 

[JB @ C and L Machine]

seems like the orignal title of this thread was altered. .

 

[Andy Redmond]

Ok KRS, there are no absolutes too right? Maybe Mr. Murphy will take up residence on the left coast so I can make some money without his constant help!



Andy

 

[krs]

Aw, Andy, I'm sure that we can agree about heads and Cummins, good and bad, but in this case I think the queston has to do with whether some of the factory 12 valve cylinder head castings have the capacity to flow better after port work than other castings do.

It's a hotrodder's area of interest as they are usually looking for any way to squeeze out that last bit in order to improve their E. T. s and speed.

I haven't heard of this belief as applied to Cummins heads but it was always a subject of conjecture and even superstition concerning both Chevy and Ford heads years ago - and may be still.

With the interest in diesel drag racing now it wouldn't surprise me to hear that some of the heads are believed to work better than others and I'm hoping to find out which casting numbers to look for so I can check both of mine. Could be some bucks in it, who knows?