mk1 estate head gasket help

[cnicholson]

Hi,

I have been helping a friend to fix his mk1 estate today, the symptoms where that the coolant was blowing back out of the expansion bottle, (new rad fitted and thermostat removed to no avail ((not by me))

So we took the head off and noticed no obvious sign of leaks on the head gasket, the bores look good, however one of the inlets (no4) looks white, if my memory serves me well this is sign of it being steam cleaned?

any thoughts please

I have advised that they get the head checked over for leaks and flatness before we consider re-assembly.

this is the first time i have worked on the mk1 engine, so would be good to get opinions on this one.

[TedTaylor]

Not really any difference in design principles between Mk1 and M2 heads apart from the uprating details - inlet valve sizes, head thickness, and higher inlet ports and thicker head studs on later Mk1 and Mk2 engines

Your 'white' valve looks like the exhaust and is a normal colour, in fact I would have expected the other exhausts to be the same.  Just looks like things running rich though if engine had been running on choke this would have made the mixture rich of course.

Was replacement rad new or supposedly good second hand because this could still be a blocked cooling system - removal of the thermostat does not always help.  Check all the water passages are clear and all the hoses sound internally because if they are breaking down a flap of rubber from the inside of the hose can block it.

Use long straight edge along head and block and check to see if feeler gauge slips underneath - this would give you indication of distortion.

MUT

[Richard B]

1526 wrote:

and thicker head studs on later Mk1 and Mk2 engines

Slight correction Ted, AFAIK all MkI 2000's had the 3/8" UNF studs, only the MkII's had the 7/16" unf studs.

Unless they have been modified.

[TedTaylor]

Richard_B wrote:

Slight correction Ted, AFAIK all MkI 2000's had the 3/8" UNF studs, only the MkII's had the 7/16" unf studs.

Unless they have been modified.

I understand that the later Mk1 engines were uprated in a number of ways including the raised inlet ports, larger cam shaft bearings and the larger head studs.
I have a scrap late Mk1 engine outside so I'll stagger out there in the morning and measure the studs!

MUT

[cnicholson]

i see your point about the lean rich argument, other than it runs on carbs, so why would you only get the white very clean inlet and spark plug on cylinder number 4? you would expect it on 4, 5 and 6 this is surely a sign that something is wrong with the combustion in this chamber?

when the head gaskets go on these how do they usually show? the head bolts where 9/16 from memory it looks completely original, I suspect it is the first time its had the head off it.
another odd thing i noticed is that the water inlet by the pump has a copper sleeve was this standard design on the mk1 head?

[ferny]

If it was from steam the whole combustion chamber would be clean, which is doesn't appear to be. However, if the inlet valve on the cylinder wasn't set correctly it'd restrict the fuel it's getting and make it run leaner than the others. Could have been set incorrectly by mistake or caused by worn rockers making it impossible.