[TR] Radiator Cap Pressure Rating

[Dave1massey at cs.com]

In a message dated 8/13/2007 7:38:03 PM Central Daylight Time,
75TR6 at tr6.danielsonfamily.org writes:
> While poking through the 6-Pack forums, I saw a post on the impact of
> radiator caps and thermostats on cooling the car. I understand the
> thermostat impact but what does the radiator cap do cooling wise? It
somehow
> raises or lowers the boiling point? I checked and my car has a 4 lb cap
> while Moss &TRF state that a 13 lb cap is needed for my model year. Does
> the 4 lb cap make the car run hotter or cooler?
>
The cap will not make the car run cooler but it will allow it to run hotter
without boiling the coolant.  If your car is boiling over with a 4 lb cap, try
a 13 lb cap.  If it ain't boiling over, don't worry about it.  But the 13 lb
cap will put more stress on the cooling system.  That's the trade-off.

Personal experience: When I put my TR8 back on the road I used my original
cap (in an ill-advised attempt for originality) which unbeknownst to me was
not
holding pressure at all.  Result: no problems during the month of driving
around St. Louis but as soon as I hit 5,000 ft in altitude I had serious
boil-over
problem when I shut down. One of the many things I tried to resolve the issue
was replace the cap and voir l`, problem solved.  Even at the almost 13,000
ft mountain passes in Colorado.

The short answer is if it ain't broke, don't fix it.

Dave