Well, I finally got the head off. Every bolt was a challenge, but they all
yielded. Now, I'm not sure how far to take this. (I've appended an earlier
post explaining the car's problem).
First off, the head gasket is copper and the head bolt torques seemed
inconsistent. Also two of the studs were loose. So the initial
recommendation I got to retorque the head bolts might have been a good one.
Hindsight is 20 - 20 and that water's a long way over the dam.
No clear indication of a blown gasket, but there might be to the practiced
eye. I'm not even sure what to look for. There is a bit of rust on the
head on the right side, especially at the front and back.
There is a modrate carbon buildup on cylinder 1 (front) and light on 4
(rear), sort of like pebbles, but very little at the top of the cylinders.
2 and 3 are clear. There is carbon all over the valves on all four
cylinders and the plugs are disgustingly fouled. So bad its hard to
believe the engine still ran. As can be seen below, I have low cylinder
pressure across the board and somewhat lower on 3.
It seems I should at least decarbonize the thing. Also, I am inclined to
have the head rebuilt even though the car has only 50K miles on it and sat
idle for 30 years - at the very least to get the hardened seats for use
with unleaded fuel. Also, it may be that the valve stems are loose. How
would I tell this and if there were more substantive reasons for a rebuild?
I guess I should also check the head to see if it is warped. Bottom line,
having invested all this effort into taking the head off, I don't want to
put it back on unless it is as good as it can be. The head is so simple I
think I should be able to take it to any good machine shop, rather than to
one of the LBC mechanics in the area. Do others agree? Are there any
pitfalls I should watch out for?
Nonetheless, I find myself thinking the effort will be futile, since low
cylinder pressure indicates a probable ring problem. The oil pressure is
good even on a hot day - around 45 - 50 psi at highway speed - so I'm
guessing the bearings are ok. I've been toying with the idea of replacing
the piston rings (Jack Brooks has been helpful on this one, since he just
did his). But, I'm almost certain I would need to hire someone else to do
it. I could probably get it apart, but it would be torn down for months,
given my rate of progress and I would fear corrosion. Also, as soon as I
went after it, I would immediately want to scrap the liners and go for an
87 mm set. So many decisions!
I know I've asked this one before, but what do people think would be the
best course of action, given the new info regarding the state of the
cylinders?
Lastly, are there precautions I should take so as not to cause problems now
that the head is off?
Many thanks.
John Cowan
My '60 Tr-3A has an acute problem. Began running it at higher revs because
the plugs were fouling. Brought it home one day after a run and it boiled
over. There was oil in the water. Later, started up with the radiator cap
off and saw fumes bubbling out above 1400 RPM.
It looks to me like I shouldn't drive it anymore, but instead, remove the
head and see if the head gasket is toast (possible - since the car sat idle
from '67 until '95) or if the head is cracked or warped. Any other
suggestions at this point?
The car also has chronic problems (even when I was driving it in the
Sixties). Put simply, it's gutless compared to other TR-3s and to the
TR-4A I bought last summer. Gas mileage is between 10 and 20, even after a
carb rebuild. (tuned as best I could). Engine temperature is usually quite
low (just above quarter mark) on a day in the 40s Farenheit, with one of
those Jaguar special skirted thermostats installed. It overheats at stop
lights or on hot days, but I corrected this symptom with an electric fan.
Compression test results are as follows:
Cylinders in order 1- 4, values in PSI
Cold
138 139 133 140
Hot
148 150 145 150
Cold with oil poured in cylinders
158 156 144 154
The plugs foul after a hundred miles or so, all four with carbon deposits -
1 and 4 with significant oily sludge, the others with only a little.
I've thought about having it rebuild and it seems like this might be an
appropriate time, while the head must come off and the good winter parts
prices are still in effect. What do others think?
Thanks.
John Cowan
Visit - In Their Own Words Website - an on-line non-commercial publishing
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