[TR] Overheating Project

Randall TR3driver at ca.rr.com
Tue Jul 10 00:16:33 MDT 2018

> A quick way to determine a head gasket issue is to check the 
> plugs. More often than not the plug in the cylinder that's 
> leaking will be very clean and almost white insulator when 
> compared to the others.

FWIW, several times now I have had head gaskets that only leak compression
into the coolant, and only do that while the engine is pulling hard.  That
forces coolant out the overflow, but without a recovery bottle there is no
clear indication as to where it went.  Usually the engine just overheats
slowly after that (due to the loss of coolant), but I have had it bad enough
to air-lock the water pump and cause instant boil-over.

On the Stag sitting in my driveway, I could fill it up and drive all day if
I was careful to never get on the throttle.  But floor it to go up a freeway
on-ramp, and it would be boiling by the time I got to the top!

On two TR3 motors in a row now, the problem appears to be because the top of
the cylinder block is not perfectly square to the liner seats inside.  As a
result, the liner protrusion is different from side to side.  And of course,
for a long time, I was only checking the side where it was within spec :(

My "short term" solution has turned into a long-term solution (almost 20
years now on two different motors): a circle of .016" (26 AWG) bare copper
wire tacked around each cylinder with soft solder.  Obviously it would still
be better to have the block decked, but the copper wire has worked great for

-- Randall

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