John, & everybody....
My experience with head removal of the Vanguard/TR engine is that you shoul=
d be careful. The cylinder liners CAN move upwards a small distance when t=
urning the crank if no restriction on the upward movement of the liners e=
xists. This movement may break the seal between the bottom of the liners a=
nd the =22o=22 ring seals, and this, in turn, may not reseal correctly when=
the head is tightened down and the liners =22squashed=22 back into the =
=22o=22 ring seal - probably because they lose flexibility with age.
The end result, jacket water leaks into the oil pan. First noticeable when=
the oil level on the dip stick starts to rise=21 If this happens, a strip=
down is required to install new =22o=22 ring seals (I have done this witho=
ut removing the engine block but would not recommend it).
My opinion on head removal is to undo the head bolts, and =22jar=22 the hea=
d loose with a hardwood block and hammer with a sideways/upward movement. =
Then lift the head off. Do not turn the crank over as the piston/liner fri=
ction may cause the liners to lift.
Once the head is off, make up small stays that can be bolted under the head=
studs to clamp the liners against their =22o=22 ring seals. Then you may =
turn the crank over to clean the top of pistons etc.
For those who asked, the reason MGB engines do not have this problem/need t=
his care is that they do not have removeable cylinder liners.
On assembly, make sure the liners protrude above the block a small amount s=
o that when the head is tightened down, the head/gasket ensures the liners =
are clamped hard into the =22o=22 ring seals at the bottom. I haven't got =
the liner protrusion measurement at hand but from memory it was about 0.003=
=22.
If you have not got a small protrusion you run the risk of not having the l=
iners clamped in place and subsequent leakage.
Generally, I have found if you do not move the liners by turning the crank,=
you will have no problems with a standard head removal/replacement.
Hope this adds to the discussion.
Best regards, Fred Birkbeck
and after reassembly,=20
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