Cracked head

[mykal41]

Does anyone have any leads on good used heads, or a good source for a used one. Got a 91 in the shop. Small cracks around the injectors. I tried just swapping the head gasket and reinstalling ( after cleaning it up ). Gauge is still all over the place (hot - cold) then pegs hot. Not to mention I can visibly see the leak between 5 and 6 on the passenger side of the block.

No coolant in the oil, no oil in the coolant.

At this point I think a new gasket and good head is the next step.

On a different note, This truck needed a radiator and I had a brand new 2nd gen laying around- So, was not bad at all a little clearance work and it fit right in. So the cross flow design should help once we get the head swapped.

Thanks in advance
Mike

 

[JLEONARD]

What size injector holes?

And where are you located?

 

[mykal41]

I am in new york, On the east end of Long Island. It is an early non intercooled head. Thats the 7mm right?

 

[cerberusiam]

I am in new york, On the east end of Long Island. It is an early non intercooled head. Thats the 7mm right?

9mm I believe, the 7mm are better as they mitigate the cracking around the injector ports.

 

[JLEONARD]

No... that's the 9mm holes (larger holes, less material in the head, hence the greater tendancy to crack)



I'm sending you a pm



Jay



(I was in Shelter Island (Coecles Harbor) last weekend)

 

[dpuckett]

Was the head perfectly flat, with a near mirror finish to it? If not, or you dont know, I'd say that's more likely the culprit than the injector bore cracks. I had an early 91 with a crack between the injector bore and intake valve seat. Guy at the machine shop said he'd seen Case tractors run with cracks twice that size, so I ran mine another 70K like that. Never had any problems.



As for the temp gauge being all over the place, that could be a thermostat.



Or you could have huge cracks and need a new head.



Daniel