[T3] Cooling options

["Steven Ayres" <comwest@att.net>]

JimA=> I don't think it is at all clear whether
=> a mixed setup is better than the early setup.

It's significantly (but not tremendously) better, says the good experience
here in hot country.

This is a good segue to a note I've been meaning to write on the
modifications I've done for cooling. As many will remember I've got a 1641
with 041 large-valve heads and certain other performance mods to give it a
little lift from stock. This car is a regular long-distance driver, and I
put in a lot of low-desert and mountain highway miles. That and the larger
displacement make additional cooling capacity especially attractive here.

Besides careful building and tuning, over the past year I've done a couple
of mods that have made a major difference. First, we carefully modified the
tin and installed a Type 4 oil cooler. More recently I added a 1.5-quart
deep sump. The rest of the cooling system is essentially stock. Together
these changes have lowered oil temperatures radically.

In a static warmup test last week (i.e. standing, so there's no external air
flow to assist cooling), we had to run the motor at about 2200rpm for 25
minutes with a blanket over the intake to get it up to 185 degrees F at the
sump, where it stopped rising. (Note that the 34s have open intake drains,
so some intake air was coming up through these from the sides of the body
near the exhaust).

Incidentally, if you're installing a temp sensor in the sump (deep or
stock), don't use the boss on the rear (where any sensible person would put
it because the sensor is protected from road debris there). This area picks
up hot air from the cylinders, and your readings will be skewed
dramatically. Use the side or front.

These modifications are much more than most cars need. I offer this as a
data point for those in special situations.

Steven Ayres, Prescott AZ
'66 KG1600

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