Engine/Transmission (1994 - 1998) Cracked head!

[CumminsPower98]

I just pulled the head on my cousin's '97 this morning because it was starting to blow a tiny amount of compression into the cooling system. It has run for several months now with small amounts of coolant leaking into the crank case. We put in some BG stop leak and that fixed it for a while until now.



I replaced the gasket with the Marine version one year ago and about 40k miles of HARD pulling (up to about 36K GVW) over mountains and such. The engine has about 330 RWHP and has run at 1200º up many long mountain passes. The truck has about 175k on it now.



I did not see any sign of leakage from the crack area. I did however see in the gasket where it was blowing compression in a few spots in the front two cylinders. I did not have the head surfaced the first time around. It seems to be about . 008 low in the center when measured from end to end, which is within specs as far as I know.



I figure the head is probably junk but would like some opinions on where to do from here. If I for sure need to replace it where would be a good place to start looking? My cousin is really short on money so this is a really bad deal right now as I know heads are not cheap. Any advice would be greatly appreciated.



Mark

 

[CumminFast]

I have an extra head pm me if you are interested.

 

[wsmalley]

I think with as much hard towing as you do you might be better springing the extra money to get a marine head put on there. If you have to replace it, replace it once and do it right. You can get a marine head with stainless steel valves and seats, it's thicker, stronger, and comes o-ringed. You are gonna pay a little more for it but it WILL be worth it. Give Jeff Garmon a call and he can order one for you... . 866-898-8585

 

[Joseph Donnelly]

Three types of cracks are fairly common: randomly spaced on the exhaust seats; from the exhaust to the intake seat; from the intake seat to the injector hole. #1 runs hottest usually if the head is not ported. Often the cracks are not too deep. Try to figure out if the cracks are the problem, or head gasket failure from insufficiently cleaned surfaces, warped surfaces, too rough a finish on the surfaces (if you can catch your fingernail at all, it's too rough), or a defective gasket.

 

[CumminsPower98]

I have another question. I found a head locally that seems to have no cracks but it is warped about . 014 end to end. We are having it planed and a valve job done. I am a little unclear weather or not I need to install a thicker gasket to maintain stock compression or close to it? The machine shop says I don't need to go for a thicker gasket but from reading on here in the past I was under the impression that when shaving the head a thicker gasket was needed.



Thanks,

Mark

 

[Joseph Donnelly]

Definitely use the . 020" thicker gasket, Cummins 3283339 for 12 valves.