Hi
I have come here for information for a couple of years and always found what I needed until today. Thanks for being here!
I'm slowly rebuilding my 4ZE1 and am about to install a new AMC head. What caught my attention were the small round coolant holes between the cylinders in both the block and the head. Only the intake side holes appear in the head gasket. The exhaust side passages would be blocked by the gasket.
The old gasket shows indentations where the exhaust side were covered up, but this gasket only lasted a couple hundred miles. It was on the old head (casting #2) which is long gone.
Is there something wrong with this picture? I thought I'd read something about this here at one time but can't find it now. I can't be the first person to scratch my head at this.
Thanks for any help.
Bob

Bob,

I'm not sure I have a specific answer to your question about coolant passages, but perhaps I can point you in the right direction and provide encouragement.

Several years ago I replaced the head on my Trooper (2.6), (casting #4), with a new AMC head. I got tired of replacing head gaskets. It's the best repair job I've ever done. I haven't had a gasket issue since.

I used a Felpro gasket, and had no problem. Of course, make sure you have it right-side up. That might make a difference. I don't recall seriously questioning the coolant passages. Maybe I just assumed that Felpro knew what they were doing.

I don't know whether they'll help you or not, but you might want to take a look at the pictures I've linked to in my sig block. You can readily see why I replaced the head.

Hope this helps a bit.

Thanks Trooper-san
I found the old link that brought up this question back in 2001 but it went unanswered. Your photos clearly show the gasket covering the 3 small passages on the exhaust side. Maybe they're supposed to be closed off but it sure bugs me.
I'm using a factory Isuzu gasket set this time (I think last time was Felpro). Block has been decked slightly so I'm planning to shave down the dowels/alignment pins a touch.
This has been a long strange repair starting from the classic coolant blowing out the radiator overflow. I never did see any cracks in the head and neither did the machine shop. Block was not re-bored, but cylinders were re-honed and new standard size pistons and rings installed. That was probably not necessary but the local shop ran with it before I could have any say in the matter. The new AMC head eliminates any guessing about cracks and should give the SpaceCab more happy miles.
Bob

ya my 2.6 has holes that are plunged up with the gasket too.

i talked to the dude that did my engine and head machining. he said that is important so that the coolant spends the correct amount of time in the head, and has the correct flow rate. and not to cut out the gasket. not sure of he was full of it or not but I've never had any cooling issues...

Thanks Steve. Every picture I can find of a removed head shows the gasket covering the holes. This seals the deal. I'm ready to install.
Thanks for the replies. This is a great forum.
Bob