Cylinder Head Removal

[SMW]

At Mike's request, here is a copy of an email I sent to the 240z.org mailing list:

A question was asked regarding cylinder head removal, here is what I did with my L24 w/ E31 head:

Tools:

The specialty tools include a good torque wrench, and a 10mm hex socket for the head bolts. I found the socket for about $5 at OSH. Any place that sells a good selection of craftsman tools should carry it.

Preparation Work:

One of the time consuming parts of this job is the removal of the air cleaner, carbs, intake and exhaust manifolds, and fuel lines. Lots of liquid wrench is a good idea, along with a good labelling system for all of the wires and hoses.

Steps:

1. Remove valve cover and put some penetrant on the head bolts to soak in.

2. Drain coolant (all the normal cautions). Remove the rad hose at thermostat and heater hose at rear of engine.

3. Set to TDC. I like the screwdriver in the #1 sparkplug hole approach.

4. If you only want to deal with the head, secure the timing chain with a block of wood (1/2" thick, 1" wide, ~7" long, tapered at the end) securely driven in to keep the chain tensioner from moving. A good idea is to drill a hole in the block and tie some wire or rope in to facilitate removal. This step is only necessary if you don't want to change the timing. If you are going to tear down the short block, this step probably isn't necessary because you will have to reset timing on reinstall. MSA sells a plastic tool for this, if you prefer.

5. Remove fuel pump.

6. Remove fuel pump eccentric and cam sprocket (note which of the three timing marks the sprocket is set at). Fold excess chain on top of wood block.

7. Remove the two small bolts at the front, between the head and the front cover.

8. Clean gunk out of head bolts to ensure that the hex wrench can fully engage.

9. Now loosen the head bolts in order (to prevent warpage). Start with the two closest to the firewall, then the two closest to the radiator, next two closest to firewall, next two closest to the radiator, etc.

10. Make sure everything is disconnected, then remove head. Don't pry between head and shortblock, this may damage the seal on installation.

This set of steps is taken from a combination of Haynes, FSM, and Monroe's "How to Rebuild..." It should be noted that I am not a pro by any stretch of the imagination, and I highly recommend having one or more manual(s) on hand for this job. Others with more experience may also have some tips on this job.

[EricB]

I read SWM's article regarding the cylinder head removal and I do own a 10mm allen wrench socket but it seemed to fit a bit loose in all the head bolts I tried... Granted there was still a bit of oil left inside them as I hadn't completely cleaned them out yet.... but it did make me wonder if the next size up wouldn't be better suited.... of course i found no 11mm allen wrench socket at the local hardware store.... now my head bolts don't look like they are stripped or "opened up" too much... has anyone else experienced this?

Thanks,

-e

[spunkysandoval]

Hi! I'm removing my cylinder head, but that darn thing won't come off. I got all the cylinder head bolts off, and even the two little ones at the front. I think the head gasket is acting as a bonding agent, and is holding the head to the block. Is there any tips for getting that damn head off?

I was thinking of using a cherry picker. Is this a good idea, or will it warp the head if too much force is applied?

Thanks,

-Isaac

[JEFF]

Smack it hard with a deadblow hammer near the block on the passenger side, ( do not hit the timing chain chamber).

If you use a cherry picker ---- "tap" with the deadblow hammer on the valve cover gasket surface(straight down) when the cherry picker has some pressure applied.

These ways have both been successful for me without damaging

anything.

- Jeff

[Dtsnlvrs]

Double check that all bolts are removed then use a soft faced hammer...ie lrather, wood, or brass, and tap along the side of the head...you should be able to "pop" it loose.

[Dtsnlvrs]

Take a soft faced hammer, like brass or wood etc, and tap around the sides of the head...that should "pop" it loose.

[kmack]

Use a good sized rubber mallet or dead-blow hammer and tap on the sides of the head. At first it will sound solid, then you'll hear a somewhat hollow sound. the head will then be loose enough to pick it up off the block.

[spunkysandoval]

I got if off easily. I had a little jack that i used to apply very little pressure to the bottom of the head. I poped right off. I't's at the shop being inspected right now. I hope they give me a good report.