[TR] TR4A overheating

[John & Pat Donnelly]

Hi Dave,
Like you I initially had the same problem on my new engine startup last
month, and it was the thermostat. I verified it by actually watching water
come out as the engine heated up.

BTW, the normal temp range for TR4A is using a 165 deg thermostat with a 4
lb radiator cap. The 180 will obviously make it run a little hotter.

Johnnie

> Hello List,
> I would like some suggestions on trouble shooting a overheating
> problem.
> 
> I have just recently started my 1967 Triumph TR4A and while it runs
> fine, I have a overheating problem.
> A little background first;
> 1. Rebuilt engine which included boiling out the block.
> 2. New 6-vane water pump.
> 3. 14 inch electric "puller" type radiator fan.
> 4. thermostatic switch plumbed into new stainless steel down tube from
> water pump to lower radiator connection. (closes at 97 degrees C, opens
> at 67 degrees C) 5. New 180 degree thermostat.
> 6. Radiator was rebuilt with new core.
> 7. 50/50 mixture of antifreeze and distilled water
> 
> Symptoms;
> I start the engine and it warms up quickly and within 2-3 minutes the
> temperature gauge is on "H". The top of the radiator is hot. the down
> tube is cool so the thermostatic switch won't close.
> 
> What I have checked so far;
> 1. Removed the two wires from the thermostatic switch (control and
> ground) shorted them together and the electric fan starts.
> 2. Removed the thermostatic switch, tested it and it works fine.
> 3. Verified that the thermostat works.
> 
> I am down to suspecting that the radiator is somehow clogged up but
> would like to make sure there isn't something I have missed before I do
> that as it is a PIA to get out with the electric fan wired up.
> Any ideas??
> Thanks,
> Dave Connitt