Rebuilt Cylinder Heads

Okay, I've done some searching but some places have lead me to some dead ends as well as old companies that don't seem to carry what I need anymore...

I am in search of an 0630 rebuilt cylinder head for my 96 4.0. I'm almost certain that I've got a cracked head on the new purchase but instead of purchasing some used head I'm willing to spend the ~$200 on a rebuilt one.

If anyone that has done their recently could post up the place of purchase, cost, as well as any other information about the product that you feel is relevant (was it a POS? material? components? cast number? etc). Also, I'm looking for something to simply bolt on, lube up and go. I don't want to waste my time with buying all individual components and piecing together.

Thanks in advance and hopefully the information contained will be a one stop shop for anyone looking at options for a rebuilt cylinder head.

Ebay. I bought a remaned 7120 head from Odessa Cylinder head for $260 shipped to my door.

Clearwater Cylinder Head and Alabama Cylinder Head have moved a LOT of Jeep heads and are very reputable.

I'd check out their websites to see if they have what you want.........

So far the places/prices I've got are as follows:

Odessa (new): 392
Odessa (rebuilt/reman): 260
Clearwater: 300
Alabama: 495

I'm certain there are many more so if you have gotten a remanufactured head from another place please post up. Thanks

I bought one from Clearwater a couple years ago for my 88 XJ. Excellent service, easy to work with and great product. Came complete and ready to bolt on.

I am in the process of buying a new head myself. My '01 head cracked and was probably going to go with Clearwater because they are reputable, have a good warranty, and is a decent price.

I would also really like more info if anyone can please provide it.

Thank you!

I went clearwater. Still need to install it, probably this weekend if my compression checks out. If not, time to do the bottom end...

I'm having a problem...

I installed the head and gasket and now I'm trying to check the compression but without any rockers or rods installed (i.e. no open valves) I'm getting air coming through the intake and exhaust ports. My compression wont read anything really.

Did I do something wrong to get air blowing past the valves or is there something wrong with this remanufactured head?

doesn't work like that. finish assembling valvetrain. then check compression.

Cascade Carl said:

doesn't work like that. finish assembling valvetrain. then check compression.

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Care to elaborate? I really dont' see why it wouldn't work. If there's no downward force on the valves why would they not be fully seated and sealed?

I'm sure the valves are sealed. But by keeping the valves always closed you prevent the cylinders from filling with air prior to the compression stroke. What would happen is each cylinder would swing between some vacuum to some compression with every stroke. Give it a try you'll see a difference on the gauge with the valves working.

Cascade Carl said:

I'm sure the valves are sealed. But by keeping the valves always closed you prevent the cylinders from filling with air prior to the compression stroke. What would happen is each cylinder would swing between some vacuum to some compression with every stroke. Give it a try you'll see a difference on the gauge with the valves working.

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Well based on what I'm seeing the valves aren't closing... When I rotate the cranksaft and put my hand over the ports there is significant suction/blowing depending on the stroke. There's definitely not a very good seal on the valves.

Okay, I have installed the entire valve-train but I'm still getting no higher than a 15psi reading on either compression tester that I have... I have installed the gasket and new head to the specified torques and the compression isn't going anywhere. I'm thinking even with bad rings I should still be getting well above that reading.

I can feel significant resistance on the compression stroke also as I'm turning the crank.

Here are some possibilities:
1. Bad gauge. Maybe check it on a known good engine.
2. Timing chain is way off. This could be bad news for the valves in your new head.
3. Damage to cylinders or pistons. Probably severe enough to see when you had the head off. This you typically see in just one cylinder tho.
4. Bent push rods.
5. Cam lobes wiped.

If you have a dial indicator or other means of measuring valve lift it will help narrow it down without disassembling. But start with #1. Good luck.

1. Tried two different gauges, both brand new.
2. Doubt the timing chain is off. Before I took the motor down the car ran just fine, aside from the coolant getting into the ports. White exhaust, the usual cracked head signs also. The head that I have is a remanned head from Clearwater. I also did the compression check without any of the valvetrain on (just valves with springs, so all valves should have been closed). I was getting the same issue, i.e. air blowing into closed valves as well as out.
3. Pistons are fine. No scoring and no damage to piston tops... Rings appear to still be there also as when I would rotate the crank to clean out the carb cleaner and carbon deposits (that I was cleaning off) there would be residue on the cylinder walls... The rings were keeping that stuff from dropping down into the block. Granted, the reason I'm doing this test (or trying to) is to see if my rings are shot. Either way, worn out rings aren't going to cause me to have a compression of only 15psig, unless they were almost non-existent, but then of course my cylinder walls would look like they've been to hell and back.
4. Push rods are all straight, I rolled all of them across a table.
5. Cam lobes probably aren't wiped as I can see the correct movement in all of my valves while rotating the crank.

The valves certainly aren't seating themselves. I had a buddy rotate the crank through the strokes and stuck my fingers down into the ports to feel the valves as well as any air passing... On the compression stroke with valves closed you could hear and feel air pushing past them on both valves. The sound I was hearing was the same sound as when only the valves and springs were installed, thus the problem lies with the valves (and them not seating properly) and not with the camshaft, pistons, rings, etc.

Kind of upset that I'm having this problem with this head considering it came from Clearwater which everyone has said is very reputable... I will call them tomorrow and see about getting a new one.

Also, the 0630 head that they sent me didn't have a drilled/tapped hole for my coolant temp sender that should be on the top of the back side of the head... Hopefully I can get them to send me one with that hole as well as with valves that will actually seal properly.

are you using the starter to turn the engine, or are you turning it by hand?

Only the 96 0630s had the boss tapped in the rear for the dash temp gauge sender, some are tapped and plugged, but most 0630s(97-99) won't have it. The 91-95 7120s have it and have identical port dimensions as the 0630s, so if they can't come up with an 0630 head with it, specify a 7120. J@C Enterprises have pricing similar to Odessa: http://cgi.ebay.com/ebaymotors/REBU...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Shorty said:

are you using the starter to turn the engine, or are you turning it by hand?

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I'm turning it by hand. I get to the compression stroke and there's definitely resistance but as I turn it harder you can hear/feel air going past the valves.

gradon said:

Only the 96 0630s had the boss tapped in the rear for the dash temp gauge sender, some are tapped and plugged, but most 0630s(97-99) won't have it. The 91-95 7120s have it and have identical port dimensions as the 0630s, so if they can't come up with an 0630 head with it, specify a 7120.

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I will most likely ask for a 7120 if they are going to let me do an exchange, or at least ask for an 0630 if it has the port for it.

ty20404 said:

I'm turning it by hand. I get to the compression stroke and there's definitely resistance but as I turn it harder you can hear/feel air going past the valves.

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crank it with the starter and listen for at least two complete revolutions before you stop cranking. You'll never be able to generate enough torque, quickly enough to see valid numbers by hand.

Use the stater motor that will sure help, and buy a chiltons for yourself please.:rtm: