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Discussion Starter · #1 ·
I was going to get the Clearwater head, but I think I am going to get the AMC head and have it checked out at the machine shop. Anyone have any experience having an AMC head milled with a valve job and have it work?

I don't know if it's worth pulling the AMC head or just getting a new one from Clearwater.

I also found a 1993 pickup that had what looked to be a brand new radiator in it. Will this bolt into my 1989 Trooper? The pickup has a 2.3 and it appears to also have an aftermarket head being that it has no casting numbers on the back. Might be a good score for someone who needs a 2.3 head. This one looks like someone put a fresh top end on. The belts and radiator hoses look brand new and even have the stickers on them.
 

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I was told by Aluminum Head Rebuilders that the AMC was stouter casting. Whether that is true or not is a different question. Other than that I am not sure that there is anything special about the AMC head that makes it desirable. How much does the pick-n-pull want for the head? How much does the machine shop work cost in your area? Compare that to the price of a new head and what to do should become clear.
 

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Discussion Starter · #3 ·
I went ahead and got it. I paid $55 for it and it looks like it wasn't on the vehicle for very long at all. The head gasket came off and the block surface was real clean. Looks like someone recently did a top end and changed the timing belt and water pump. The rest of the motor was real dirty.
 

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Man that is awesome! I have the AMC head on my 90 Trooper..it was on there when I bought it..checked it out when we rebuilt the motor..all was good. What was the mileage on the trooper at yard? You may be able to get a ballpark on the age of the AMC..Its only an assumed guess but if it had lower miles then chances are the original head lasted close to 100k I would think..everyone I ever knew from new made it to 100k if there wasn't an idiot factor involved..I always check the the heads at the yards..nothing cool yet...
 

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Discussion Starter · #5 ·
It came off of an unassuming 1991 Rodeo that was 2WD. The odometer was about 135,000.

I always check the Salvage Yards. I'm in Phoenix so there are a bunch of self service ones. I needed a radiator for my Kia, but I check for Isuzu stuff whenever I go. Sometimes I buy stuff I know I can get cheap and re-sell to pay for the parts I need.

I got my trooper in March. The previous owner had the motor rebuilt but the head gasket blew after 10,000 miles. That head is cracked. All I need is to get the new head situation sorted out and I should be good to go. I still don't know what it's like to drive an Isuzu yet.
 

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Before you install that AMC head make sure you figure out why the motor blew the head gasket and cracked the old head or you'll run the risk of ruining the "new" AMC too. Take the money you saved by scoring a decent condition head in the junkyard and grab a new radiator, t-stat and water pump. I did this after I cracked my head and it made a big difference in how cool / constant temp the motor runs.

Oh yeah, I forgot this in the first post: Cool score!
 

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Yes, on an older 2.6 motor, be sure to replace the hoses, t-stat, and radiator.

And welcome to the Zoo, you lucky guy. :thumbup:
 

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if its a one core radeater, changing to a two core will help with the over heating.

also having a good clutch fan. is a major step in helping to control over heating.
 

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Discussion Starter · #9 ·
I'll certainly replace the water pump, radiator, and hoses then. Especially living here in the desert. I plan to use the OEM thermostat and head gasket.

I'm kind of dreading finding a cylinder head shop that's trustworthy. I want to make sure the AMC head isn't cracked and make sure it's flat. It's tempting to clean it up, check it with a straight edge and feeler gauge, and bolt it on as is.

If I find another one of these heads I'll post it on here and get someone a good deal on it. If there's one, then their has to be more waiting to be found.
 

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There are a few pics pics for spaghetti hoses used for vacuum lines.
 

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There is no reason you cannot use the head if it is truly flat. All you need is a precision straight edge and a .002 feeler gauge. If the feeler wont fit under anywhere your good to go. But remember to do the same to the block. A straight head on a wavy block is just as bad as being the other way around. New head bolts should always be used and if there is a torque angle spec for tightening the head then use that rather than just a standard final torque spec.

If you want to check for cracks you don't need a shop to do it. All you need is a dye penetrant kit which you can find at most parts stores or any welding supply store. Just spray on the dye and let it sit a couple mins. Then wipe with a damp rag or mineral spirits (read the instructions) and then spray on the developer and any cracks will show up like the light of day.
 

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2.6 head bolts are not Torque-To-Yield and can be reused if the sockets and threads are in good condition.

Be sure to chase out the head bolt holes in the block with a metric tap, size 12mm-1.50, and blow all the crud/rust out with air or carb cleaner etc.

And for best reliability, use an Isuzu OEM head gasket. A good friend of mine got a new head for his Trooper and the aftermarket head gasket blew out within a few thousand miles. He replaced that gasket with OEM and no problems.

HTH.........ed

p.s. good find on the AMC head!
 

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Ed normally I would agree with you on the bolts. But with the issues the 2.6L has why chance it?

I never replaced the bolts on my 3.4L for my S-10 and it has been fine but the 60 degree V6 has a good reputation for staying sealed up. The 2.6L does not!
 

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The point is that the 2.6 head bolts are Not stretch bolts.

The GM 60 deg V6 does use T-T-Y stretch bolts and they should be replaced every time. Whether or not a head gasket blows if the bolts aren't replaced is likely more up to luck or the Head Gasket G-d or whatever. But the GM bolts are readily available and relatively inexpensive.

Whether or not to purchase new head bolts which are not required is up to the individual, but it should be an informed purchase. There's absolutely nothing wrong with re-using a perfectly good piece of hardware that has nothing wrong with it.

Which is my only point. Check out previous discussions on this and you'll see Jerry L. agrees. Have a good one........ed
 

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Discussion Starter · #15 ·
Here's a few pics I took. I noticed it has one of those freeze plugs that shows if the engine has been overheated. I wonder if they come with these new or if this is there because it's a rebuilt head.

How can you tell if it has been overheated? Does this thing pop out like a turkey thermometer or something?

I am thinking about going back and buying the shortblock as a spare. Whoever had that rodeo may have put a new engine in it that came with the AMC head and never re-torqued the head.


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Discussion Starter · #16 ·

Got my head inspected and a light resurfacing. I purchased a new head gasket and various other parts to button the motor back together from Jerry. I wanted to get some opinions regarding some minor pitting on the head surface.

The machinist said the head has been repaired before, but done properly. A couple of the coolant passages were welded to build up material. The machinist said poor coolant can corrode the aluminum and if the corrosion gets too close to the sealing ring on the head gasket this has to be done. I thought it was weird considering all the other coolant passages look great. They said the head is in great shape to use.




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I was concerned regarding these small pits where the two coolant passages were repaired. I thought about filling them with JB Weld but I think I'm going to leave it as is. I figure the head gasket will fill these up with the "soft" part of the gasket.

I was worried about this, but I also know part of the gasket crushes into the coolant passages since the coolant passages in the head are larger than the ones on the gasket.




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T89 said:
Why'd you use such a large font in the second post ?

Looking at those two coolant passages, I'd be concerned that they have restricted them so much. Seems to me they should have opened the passages up a little before returning it to you.
 

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Discussion Starter · #18 ·
I got in the habit of making the font bigger when sending messages to make it easier to read.

I'm not too concerned about the size of the passage. The small one on the lower right corresponds to a smaller passage on the block anyway. The flow of coolant may be a bit restricted in those spots from passing into the block, but the flow of coolant across the head itself isn't restricted. Once I get my new gasket from Jerry I am going to lay it across the head and see how it matches up to those passages and I may open them up slightly with my dremel.

I got my deck cleaned as best I could today. Went through about 8 razor blades and did a pass with some fine 1000 grit sandpaper to polish the surface.



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I am a bit concerned regarding black areas on the deck where the sealing rings go. They look worse than they really are in the photos. There is very slight pitting in these areas that are oxidized black. The black areas feel as smooth the rest of the deck. There are only a few spots where I can barely feel any pitting running my nail over it.

I don't want to take the short block apart to have it decked, but I also don't want to have to take it all apart again if the head gasket fails. I thought about troweling some JB Weld on those areas and scraping it off with a razor blade before it sets to fill any of the deeper pits. That should leave me with a flat, smooth surface. However, everything I've read on here says not to put anything down except the gasket.



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You may want to buy a 3M roloc disk and go over the block before you put it back together.
Once you use the roloc you will be spoiled. They are a little pricey, but make such quick work of cleaning the surface it is worth it. Also the debris left behind by the roloc is not nearly as harmful as, say, a scotch brite type material.
 

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Discussion Starter · #20 ·
I finally got the head prepped. I got a high temperature aluminum based aviation repair epoxy and filled the small pits in the head. I also worked some into the water passage where the pitting was and drilled out the passages. This epoxy is amazing stuff.

Anyone think I should open the water passages up any more than this?



I got wire rod brushes and cleaned out all of the coolant passages in the head and block. Then I inserted a probe attached to my air compressor and blew all the residue/debris out with about 100 PSI. I did the same to the head bolt threads after cleaning them with the wire brush and ran the tap through them several times. I scraped the deck real good with razor blades after going over it lightly with some 150 grit sand paper. There are still some darks areas but those areas are very slight pitting that is oxidized. I think this is about as good as the deck is going to get.



I thought about replacing the clutch, but it got a new clutch when this motor was rebuilt about 10k miles ago. It's a Valeo brand clutch. I have never changed a clutch out before but it looks good to me. The pressure plate and the flywheel surface look good. Can anyone tell me if this clutch disc looks worn?



I am using the OEM gasket and thermostat. I want to thank Jerry for his assistance with the parts. He got them to me quickly and answered all of my questions.
 
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