Crack in Cylinder Head

[Greenleaf]

Where does the crack occur in/on the big bore cyliner heads (1989 Model year Cummins in Bluebird Bus)



I found a crack about two inches long directly under the #2 injector between the injector and the cylinder head bolt directly under the injector. The crack is horizontal and does not intersect the injector bore nor the cylinder head bolt hole.



When pressureized to 10 psi the coolant runs out of the lenghth of said crack.



This is the "new" cylinder head and can't recall if it's still a big bore hole or not. This head has had a # of small leaks since installed. New from NAPA.

 

[dpuckett]

The "normal" cracking occurs between the intake valve seat and injector bore.



Sounds like more quality stuff from CRAPA auto parts.



Daniel

 

[Greenleaf]

Yes. The original head was cracked in that same fasion as you described.



I have to wonder if this is actually a "used" head they sold me... ... ... ... ... .....

 

[dpuckett]

I ran my head like that for another 70K before I sold the truck. I'd say if the oil and water arent mixing, and you arent losing compression, run it as is. But, since this is supposedly a NEW head, I'd make NAPA hold up their end of the deal.



DP

 

[Greenleaf]

There is tons of oil in the coolant ans been that way for years so I don't believe it's related. As per oil in the coolant... ... ... don't see any problem with that. It lubes the pump and the cooling system will never rust, right?



I installed a new head becasue it was leaking/cracked and there was coolant in the oil. I had the oil cooler pressure tested and it was found to be sound. As long as the engine operates, I'll continue to run it. No worries, Mate.

 

[WJune]

I bought a massey Harris 444 gas tractor with excellent built up engine. It had lots of oil in radiator which I wanted to live with. Trouble was in winter the oil - antifreeze mix turned to JELLO !, then overheated. Head tested OK. Changed engine as we determined it had internal crack in oil gallery. It was pushing about a quart oil per hour into cooling system. Hopefully yours never gets that bad. Will

 

[dpuckett]

A little off topic

But how old are some of your busses? I think VE pumped busses would have to be 13yrs+ old? You guys got some good roads, then. Roads where Mom lives beat the busses up after 4-5yrs.

 

[Greenleaf]

1988/89 model year are the oldest. With the recent passage of the levey, we will begine to turn buses over at a rapid rate, so say by-by to the 12 valves and hello to the new 6. 7L ISB Common rail. :-{} Two (2) new units per year.



Is there a screw somewheres on the Common Rail to increase the fuel rate?

 

[tugboatphil]

Does this mean that Bus number 3 will soon be available?? Inquiring minds want to know! :-laf

 

[PToombs]

Does this mean that Bus number 3 will soon be available?? Inquiring minds want to know! :-laf

Doesn't that already have a home between the '90 and '92?

 

[Greenleaf]

VE powered Bus # 3 (old Smoky) will be traded in for a new Bluebird exactly one year from the first of December (2007) :{

 

[PToombs]

Does that mean no more R&D from Smokehouse Diesel?

Are we going to have to get you a box of Kleenex? :-laf

 

[Greenleaf]

The free R&D @ the Smokehouse (at taxpayers expense ) will continue. No worries there I just finished install of a (very short) straight through "muffler" on an ISB. Sounds pretty cool. The silencer rings are AWOL and The P-Pumps are begining to push fuel like they were made to :-laf