[DeTomaso] Radiators

[JDeRyke at aol.com]

MD's Ron Davis racing radiator-
Single pass (aluminum)
4 core (comes out to 6 inches thick)
30-1/4 inches wide at the widest point (the bottom side are tapered some)
16 inches tall

Ken, did you mean the overall width was 30" or only the 4-tube core? Pantera 
radiators are around 29-1/2" wide overall with the core at 26 or so inches 
wide. 

For reference to all who can't afford to experiment, a stock copper/brass 
Pantera radiator is 26" wide x 15" high by 2-1/2" thick, with a tank 1-3/4" wide 
on each side and is a dual-pass crossflow style radiator- or two separate 
designs, one of which didn't work. My 2nd design stocker weighed 40 lbs but may 
have had scale built up inside after 15 yrs of use. 

A Fluidyne aluminum is also 26" wide x 15" high but is 3-1/2" thick, with two 
side tanks each 1-3/4" wide, and is a dual-pass crossflow. It weighs 22 lbs 
without the fan shroud or shroud extension. It is a dual-pass 4-tube style.

A '90s Corvette/Z-28 radiator is a 12-lb single pass crossflow one-tube 
aluminum radiator 25-1/2" wide x 18" tall, swedged into two 2-1/2" wide plastic 
tanks. GM gets away with one tube by making the inside of the tube bumpy (Modine 
Radiators calls it a 'tubulator core'), thus vastly increasing the turbulence 
of the water and increasing its heat transfer. I've often thought of taking 
two of these good cores and welding them into aluminum tanks for a custom setup, 
but my Fluidyne works so well to 150 mph, I haven't bothered. The plastic GM 
tanks often crack from overheating and cannot be repaired so don't bother to 
try adapting stockers to a Pantera. At very low speeds around town with the 
front-mounted A/C on, I've seen 250 F in our stock Z-28. The single electric fan 
isn't even designed to come on until around 225F!

Some say that dual-pass radiators increase the restriction to flow since 
water is forced across the core twice, while a single pass radiator means that 
water is only forced across (or down) once, thus using less power or adding less 
flow restriction. Generally, water that stays in a radiator longer transfers 
more heat but the amount of temp loss from two passes is not proportional- you 
don't get twice the cooling. The actual flow restriction is a function of how 
big the tubes are and how many you pack into the space available. In our usual 
balancing act, more tubes means more water flow but less air flow through the 
core. More bigger tubes helps but there's a size limit.

Hall was an innovater! The Phoenix radiator was std dimensions but thicker 
7-core brass radiator that weighed at least 50 lbs- essentially two cores 
soldered in the same tanks, and held up to a light bulb by a strong man, no light 
could be seen, so how much air actually made it thru is problematic. Hall 
himself said they didn't work like he expected and he soon stopped selling them- 
apparently except to MD. Hall also built a few wild slanted-core radiators in 
which air from the grille flowed straight thru in spite of the radiator being 
radically slanted. This design allowed a little more frontal surface area, too. 
Never heard of any owner results on these. FWIW- J DeRyke


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