Well, I finally got to try this out and it shows a good deal of improvement. Drove the car around in light traffic through parts of Mesa Friday afternoon, and spent some time driving around my subdivision at relatively low speeds to see where the temps would stabilize in slow traffic. Outside air temperature was reported to be about 109 degrees. Highest coolant temp I observed on the temp gauge was 208 degrees. The coolant temps are running about 15-20 degrees below what I previously experienced. Temp also stabilized at about 195-200 degrees during low-speed steady driving at around 25-30 mph at 2100-2400 rpm; this is where I had most of the trouble with the old radiator/
antifreeze combination. I also observed that, once I got the car moving at 50 mph again, the temps dropped a little more quickly back to normal of about 180-185 deg. Highest observed
oil temp was about 220 deg; stabilized about 180 during steady driving. I hope to see the cooling system temperature drop a little more as I get the air purged out of the cooling system. So far, it seems to be a significant improvement over the old brass radiator and glycol
antifreeze combination. Of course, I'll still needs lots of research miles to drive to ensure this has resolved the problem (ha) but it certainly looks like a major improvement.
Turk: I'm using the stock ERA puller mounted behind the radiator. I replaced the original fan about eight months ago with the "upgraded" fan from ERA. Bob P swore it would move more air than the original one, so I switched it out, but that change by itself didn't seem to make much difference in the coolant temperatures. Perhaps it may show some difference if I were to reinstall the old fan now that the new radiator is in place, but that's another science project for another day, certainly not in the middle of the Phoenix summer. I did ask Bob P about installing the front pushers, but from what I understood him to say, the pushers don't really do much as far as cooling, and in some cases can actually cause problems by blocking some of the airflow through the radiator at the higher speeds. Apparently, they seem to be primarily for "authentic looks", although I read somewhere that they didn't help the original Shelby cars much, either.
One other item for anyone following this thread with an eye to following suit. I talked with the Griffin tech guys about the radiator design prior to ordering the unit. For those of you with ERAs, you probably know by now that ERA switched from brass to aluminum radiators about a year and a half ago, and Griffin now builds those radiators for ERA. Ron Davis Racing here in Phoenix builds the aluminum radiators for the ERA GT-40s. However, from what I understand, the 427 radiators ERA uses are double-row units with each row consisting of 1.25 inch tubing. I had Griffin construct my radiator to the same external dimensions as the original (so I didn't have to change the mounting hardware) but specified 1.5 inch tubing, which is the largest tubing they use. The Griffin tech with whom I spoke ran some numbers on a computer program and he said that, given the engine I have (FE side oiler stroked to 484 inches, 10:1 compression, aluminum heads and dual Holleys) that the 1.25 inch tube unit would not be adequate to cool my engine in the Arizona heat. This was the primary reason I went with the Griffin unit over the (locally available) Ron Davis product, since Davis would not build the unit with larger than 1.25 inch tubing.
Please understand that none of this is a knock on any of the companies mentioned here. Ron Davis was very helpful during initial investigation of my particular problem, and they would have been happy to build a radiator for me; they just have a different philosophy on design than I wanted so we politely parted company. ERA and Bob P were also very helpful and offered to supply me with one of their newer design units, but again, it didn't fit what I specifically wanted plus I would have had to change out the mounting system for the radiator. That in itself wouldn't have been either difficult or even undesirable, since their upgraded system installs the upper mount in front of the forward lip of the hood opening rather than on the aft side and screwing the fasteners into the fiberglass as is done on the older cars. Bob P was extremely helpful and even supplied me with several engineering drawings of the old style radiator, which I then supplied to Griffin for the pattern for the new radiator. My kudos to Bob Putnam and the ERA crew for helping me (yet once again) even though it didn't result in any direct income for them. Their service is still first rate in my book.
Griffin also did a marvelous job on the new unit. It works as advertised, looks like museum display quality and fit almost perfectly, with only one minor problem which Griffin had no way of preventing. The new unit duplicated exactly the square frontal area of the old radiator. However, the side tanks on the new unit were built about 1/2 inch narrower per side than the original radiator. The original radiator when mounted in the car sits on two small saddles built into the bottom tray; these saddles are located almost all the way outboard to the edges of the radiator. The new radiator was therefore about 1/2 inch too narrow to fit on those saddles. This, of course, is not Griffin's fault as I had not informed them of this requirement (indeed, I didn't even realize it until I installed the new unit into the car). However, it was easily corrected by cutting some 3X3 inch squares of 3/8 inch thick rubber material and sliding this in under the radiator to support the weight. In all, I was very pleased with the help I received from all concerned with this, and am also pleased with the final product. Thanks to all concerned.