Radiator help

[Jbarela]

Hey all trying to get the car ready for july, our car overheats with the rebuilt 2 core, I read that I might have over painted it causing problems with heat transfer. Swapped in a three core and no problems overheating, yes I did not paint that one lol. I am convinced I over painted it as I cant imagine that the car would overheat always with the two core. My question is can I get away with a three core or is that a few points deducted? Also with a three core does everything still bolt up without issue like the fan shroud, how about fan clearance? Thanks in advance!

[silverton_ford]

If showing in concours, then you will have points deduction.

I run a 3 core radiator in my car with a fan shroud and original fan.  No clearance issues.

I bought these fan shroud brackets to allow me to mount the fan shroud for a 3 core radiator.  They also sell 4 core brackets.
  https://www.virginiaclassicmustang.com/65-66-FAN-SHROUD-BRACKETS-FOR-THICK-3-ROW-RADIATOR-SET-OF-4-P1431.aspx

[Bob Gaines]

Hey all trying to get the car ready for july, our car overheats with the rebuilt 2 core, I read that I might have over painted it causing problems with heat transfer. Swapped in a three core and no problems overheating, yes I did not paint that one lol. I am convinced I over painted it as I cant imagine that the car would overheat always with the two core. My question is can I get away with a three core or is that a few points deducted? Also with a three core does everything still bolt up without issue like the fan shroud, how about fan clearance? Thanks in advance!

There are probably more forces at work if your car overheats with a 2 core vs. a 3 core . Typically the painting will not make a dramatic change in operation. Heavy paint will certainly contribute to negative cooling efficiency however on a normal running engine the difference between a normal coat of the special radiator paint and a normal coat of regular paint can hardly be noticed. More likely the engine is on the outside edge of the range that needs additional cooling compared to that of a typical stock engine because of a over bore condition ,tight fresh engine etc. Yes points deducted in concours for 3 core radiator on a 66 GT350.   

[Steve McDonald Formally known as Mcdonas]

I've run a 3 core and a 2 core and haven't seen much difference and this includes driving in the 4th of Jul Parade in Washington DC for several years in mostly 90-95 degree weather at mostly an idle speed for the 30-45 minute drive, yes it gets hot, but never overheats
As Bob says I believe the issues may lay elsewhere, timing, water pump incorrect.
Right now I'm running the 3 core with the original fan, and fan shroud with the extended brackets that they sell at Virginia Classic and other vendors with no problems. The most recent weekend I waiting in line over an hour creeping the 2 miles into Ford Carlisle, it goes towards the top edge of the gauge but never overheated or puked water out on the ground
Engine is stock at  0.30 over and is at 12 degrees initial timing and 35 degrees total at 3,000 rpm, original Hi-Po water pump with the correct impellor  and a stock Autolite 4100 carb
Are you sure the gauge is reading correctly?
Might try a temperature gun to check for hot spots in the radiator or see if a cylinder is running too lean

[Jbarela]

Thank you all, going to put the two core back in and look at the engine side.

[deathsled]

Speaking of radiators I am now considering putting my desert radiator made by Ford as an option for southwestern 65 66 Mustangs. It has never been in a car. Was found in the back of a Ford dealer some years ago in the Dakotas. Maybe I should put it in a display case instead.