VM Diesel Specialists

Mike92104 · **Posted:** Wed Oct 29, 2014 12:44 am

geordi wrote:

Mike92104 wrote:

geordi wrote:

Sleeve hits the head - Maybe it had the wrong gasket installed?

Are they actual grooves pushed into the aluminum, or is it just in the soot? I can't imagine the compressive force that would have impressed into the head and NOT crushed the rest of the thing. Wow.

The sleeves DO NOT hit the head. I'm not sure why you keep insisting that they do.

Chill out - If you read the post immediately above mine, you will see that I was quoting what FLman posted. I'm not "insisting" anything about these, other than they leak with factory bolts.

You were answering a question he asked, and incorrectly. You've made several posts disseminating incorrect information about the relationship of the cylinder liners to the head gasket. I'm attempting to correct that.

papaindigo · **Posted:** Wed Oct 29, 2014 9:59 am

At the risk of getting my head handed to me piston protrusion and liner protrusion are two entirely different things per the FSM
1. liner protrusion, can be adjusted by shims, is limited to 0.00 - 0.05 mm.
2. piston protrusion, cannot be adjusted as far as I can tell, is measured with essentially a straight edge across the top of each cylinder sleeve using a dial indicator that is first zeroed on the adjacent cylinder block surface. This measurement is used to select 1 of 3 different head gasket based on gasket thickness.

Assuming that methodology is correct the liners can be slightly above the cylinder block surface but, I presume, below the piston protrusion. If the liners are slightly above the cylinder block surface AND the head gasket piston cut out is smaller than the diameter of the liners then yes the upper edge of the liner will "impress" upon the head gasket but it will not or should not "hit" the head.

Going out on a limb I would speculate that slight liner protrusion might be a desirable thing in that it would serve as a bit or a "fire" ring at the inner edge of the gasket but that's just a wild guess.

greiswig · **Posted:** Wed Oct 29, 2014 1:32 pm

papaindigo wrote:

Assuming that methodology is correct the liners can be slightly above the cylinder block surface but, I presume, below the piston protrusion. If the liners are slightly above the cylinder block surface AND the head gasket piston cut out is smaller than the diameter of the liners then yes the upper edge of the liner will "impress" upon the head gasket but it will not or should not "hit" the head.

Going out on a limb I would speculate that slight liner protrusion might be a desirable thing in that it would serve as a bit or a "fire" ring at the inner edge of the gasket but that's just a wild guess.

CAVEAT: I'm no expert. Don't play one on TV, and I've only been inside two of these engines now. So take this with an appropriate grain of salt.

I don't think the liners are ever supposed to actually contact the head. I think you're right about the fire ring (i.e. protecting the gasket from the bulk of the radiant heat, turbulence, etc.), but I don't think that is the source of the seal. Here is my understanding of the way the gasket is supposed to seal in this engine:

The "sleeve shoulder" shown here can be at or slightly above the block surface because that is where the gasket seal faces the highest pressure differential. So "slightly above" as in .05mm is probably an advantage as long as the gasket can also seal everywhere else. But the thickness of the gasket still needs to place the head surface slightly above what I've labeled the "inner sleeve" so that the liner doesn't actually hit the head. That inner sleeve is just a part of the liner that was not machined away as far as I know, not actually a separate piece of metal. So, as I mentioned earlier, I suspect that if you compare the rings that you see on a used head with the diameter of the head gasket, you'll find that the rings match up with the gasket, not the inner sleeve of the liner. Hope this helps somebody, and if I'm wrong I welcome information that is based on something other than opinion.

Mike92104 · **Posted:** Wed Oct 29, 2014 5:39 pm

That's a great visual.

WWDiesel · **Posted:** Wed Oct 29, 2014 9:21 pm

Disclaimer, I am no expert nor have I ever been in one of these engines beyond the timing belt/water pump replacement. What I have found does support what others have stated to some degree, below is the technical side of this discussion for those interested:

This information is from a VM Morori engine manual and I think in theory the requirements are very similar?
BASIC ENGINE Cylinder head GASKET
IMPORTANT: When cylinder heads are removed for service but pistons and cylinder liners are not disturbed,use
the same thickness gaskets that were removed. Refer to Head Gasket Identification.
Refer to the following procedures during a complete engine rebuild or when pistons and liners are being replaced.
1. Use the dial indicator and Support Block tool (liner gauge bar) to measure piston height above the
cylinder block with the piston at Top Dead Center (TDC ).
2. Place Support Block on cylinder block surface and set the dial indicator to zero 0.
3. Move the Support Block tool to the piston surface with the piston at TDC point as shown.Record the measurement.
4. Measure the piston protrusion (height) of all pistons. Use the average measurement to determine the gasket thickness
required for all cylinders.

5. After determining the head gasket thickness required, identify and select the proper the cylinder head gasket.
Note the identification marks (holes or notches) in the lower right hand corner.
No mark indicates a thickness of 1.42 mm
Two marks indicate a thickness of 1.52 mm
One mark indicates a thickness of 1.62 mm

Cylinder liners on all engines are required to protrude, or rise above, the surface of the cylinder block!

CAUTION! Cylinder liner protrusion can only be correctly measured with the cylinder liners fully seated in the cylinder block. Incorrect measurements will result in engine performance problems or severe engine damage. Ensure the cylinder liners are fully seated in the cylinder block before measuring cylinder liner protrusion.
NOTE: The cylinder liners will rotate freely in the bore when the cylinder block and cylinder liner are completely clean and ready for measuring cylinder liner protrusion.
a. Unless being replaced, install the cylinder liners in the same cylinder block bore without O-rings as marked or noted upon disassembly.
b. Using a precision depth gauge measure and record the amount of cylinder liner recess (the depth below the cylinder head mounting surface of the cylinder block) of each liner.

1. Use the dial indicator and Support Block tool (liner gauge bar) to measure the liner protrusion above the cylinder block..
2. Place Support Block with the dial indicator feeler gauge on the cylinder block.
3. Set the dial indicator to zero (0).
4. Move the dial indicator to the liner on the liner neck. Record the measurement.
5. Measure the liner protrusion of all liners.
6. Verify the amount of liner protrusion for each liner as specified:

Cylinder liner protrusion- 0.0 ÷ + 0.07 mm

flman · **Posted:** Thu Oct 30, 2014 5:41 pm

Here is how the used head looked

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