<VV> Oil Temp and Cooler Location.

[james rice]

All:  I trust I am stating some obvious things here.  What the oil temp
gauge says first of all is a result of where the sending unit is located,
followed by the sending unit and wiring telling the gauge something it can
read.  All sending units may not be calibrated for all gauges.  But after
you install all this and drive it for awhile, the only useful information
the  oil temp gauge tells you is departure from normal.  Most gauges are
like that in reality.

All the comments about de-flashed and 12 plate oil coolers with side plates
is correct.

Someplace in my career at Caterpillar someone told me the temperature drop
across a radiator is only 15 deg F. at normal operating temperatures.

Mounting a oil cooler over the fan will not get you maximum air flow.
There's probably no air at all going thru it.  Air takes the path of least
resistance and will go around the cooler, unless you add some duct work
someplace/somehow.  You probably only get convection(?) cooling  All the
front coolers on race cars are tightly ducted from the new hole where the
license plate was to the exit out under the car.  Coolers are mounted
vertically or horizontally, depending on their size, and may have
thermostatically control flow.  Don Yenko had to submit new papers to the
SCCA in '67 to get the hole allowed.  The paper's show a detachable cover
over the hole.   Said papers allowed back dating of existing cars.  Of
course, no one has ever seen the cover!

The Stinger which ran the Daytona 24 Hour in 1966, which was a FIA event,
had a very large oil cooler mounted on the left rear fender.  When the car
later showed up at SCCA races, there was much consternation by the tech
inspectors, as their tech rules did not address the question of external
mounted oil coolers.  This oversight was quickly corrected by the SCCA home
office.    By late spring '66, the oil cooler was moved inside the body
work.  Jerry Thompson said they had theirs mounted so it vented, as has
subsequently been determined, into the passenger compartment.  They didn't
know which way the air flowed in retrospect, just that the oil temp,
wherever it was measured, was acceptable.  The Stingers engine compartment
and air chamber at the base of the back window is pressurized at way above
legal road speeds, thanks to the doors in the engine lid.  The passenger
compartment is not pressurized.

If I actually felt the need to add an exterior oil cooler, I'd attach it to
the center of the air chamber above the engine, and add duct work in the air
chamber and also a fairly tall external air intake to catch air as it flows
over the back window.  I think careful design of these things could be added
without new screw holes: tighten the parts against each other around
existing material.  There was a Corsa at the '66 24 Hr in the GT class
(Stinger was in a prototype class), driven by Bobby Allison and others which
had a un-ducted oil cooler mounted at the base of the back window.

Just another observation about tempters.  About 25 years ago I bought a LM
with +0.060 bore/big turbo/SU/water & alcohol-injected 140.  I was
concerned/curious about engine compartment temperatures.  So one Friday I
borrowed temperature  sticks from our lab and on Saturday, which was 90 plus
degree and humidity day, marked up the engine compartment and drove the
thing for 40 miles on the interstate.  I had sheet metal temps of above 250
deg F.  I don't remember what the oil temp was, but it apparently wasn't
alarming, as I don't remember it!  Car ran Mobil 1.  The car with the same
engine is still running.  I recently tried to buy it back.  That turkey
would haul.  I was never brave/foolish enough to really nail it, but at
study 100 mph, it was still had a vacuum on the gage.  I did see 14 PSI when
accelerating once, and it scared me!  I knew I had neither the money or
skills to fix it if I broke it.  Very strange sensation to be pushed back in
your seat while lifting your foot trying to control boost.

Historically Yours.
			James Rice