[Mgs] The Continuing Quest to Cool my MGA

[Robert J. Guinness]

Bill Wilkman Originally Wrote:

    Are there any more thoughts, given the temps I'm now experiencing
    [with my MGA] after correcting the timing and fuel/air mixture?

Rick Wrote in response:

    Since the only real indication of over-temp that you have is the
    gauge on the dash, I suggest that you may have an instrumentation
    error. BTW, any chance your FUEL gauge reads too high also? They
    operate from the same voltage regulator. If that thing sticks
    closed, everything will read too high.

      rick


Reply:

I hate to offer a correction when I am a relative novice, but I am in 
the process of rebuilding my Jaeger Water Temperature / Oil Dual Gauge 
from an MGA.  Neither component is run with electricity (only the 
external light bulb is wired). The water gauge is actually a pressure 
gauge.  The ether in the metal bulb screwed into the engine expands when 
heated.  The gauge measures the pressure as the ether expands in 
proportion to becoming hotter.  Check out Barney Gaylord's site for a 
better explanation of this and most things dealing with the MGA.
On Overheating:   www.mgaguru.com/mgtech/cooling/cool_1.htm
On the Temperature Gauge:   www.mgaguru.com/mgtech/dash/dt101.htm

Besides sticking your gauge lead into boiling water, there is another 
static check of the MGA temperature gauge.  Buy a $13.99 SunPro 
mechanical temperature gauge from AutoZone  (or comparable store).  It 
will directly screw into the head where the original water temperature 
gauge lead is screwed in (be quick, because your coolant will pour 
out).  Tape or otherwise temporarily secure the SunPro gauge dial to the 
heater shelf and secure the original lead so it is not subject to bends 
or breaks (be careful here!) .  Drive around or otherwise get the car up 
to temp.  Stop, open the bonnet, and see what you have on the SunPro 
gauge (as compared to what you were getting on the original gauge). 
Alternatively you can put the Sun Pro gauge on the floor and run the 
lead through an empty hole in the bulkhead for dynamic measurements.  
This way, you do not have to open the radiator cap and you don't have to 
rely on the indirect "infrared" gauges.

You can also use the SunPro gauge as a donor for a repair to your 
original gauge (if you are daring enough).  See:  
www.ply33.com/Repair/tempgauge
-- 
Robert Guinness
MGA 1600