Radiator Choice

[tahart]

I want to put an aluminum radiator and electric fan in my '70 GT 500. It has an AT. I live in east Texas and it's just too dang hot here in the summer. I'm tired of watching that temp gauge creep over to H! I'm curious what results folks have had with various brands? There is an endless list of choices. What should I be looking for, and which brands are the best at keeping my engine cool? Tks.

[crossboss]

Some things to consider:
1--change your thermostat to a lower one--160.
2-use an alum intake. Yes, its a days job, it may or may not be correct... IF that concerns you.
3-alum water pump.
4-make sure your radiator shroud, cap and fan are working properly.
5-check your ign. timing, plugs, and wires, etc.
6-check for vacuum leaks.
7-carb is properly set.
..along with an alum radiator will do wonders for cooling a Big Block car.

[Royce Peterson]

An electric fan is normally less CFM and more engine load than the stock clutch fan. The high end ones are the real business and to use one you will need more alternator power than the existing alternator can supply.

There's no free lunch. Switching to an electric fan for most folks is an exercise in frustration that normally results in a less reliable vehicle. Done right it can do the job, but there is really no reason for doing it. The stock setup will cool anything if it is in good shape.

[Shelbypat]

Suspect your fan clutch.

Patrick

[69 GT350 Vert]

I installed an ACP 2 Row Aluminum 24 inch radiator with 1.25 inch tubes recently.  The 20 inch radiator and the Boss 302 flex fan wasn't doing the job in the Florida heat.  After installing just the 24 inch aluminum radiator, the coolant temperatures were slightly better, but the coolant temps would still reach 210 degrees if idling in a traffic jam on a hotter day.  I installed a new Hayden 2711 thermal clutch and a 428 CJ reproduction 7 blade fan.  The clutch fan made a huge improvement - much more so than the 24 inch aluminum radiator.  I let my car idle in the driveway for 25 minutes with the hood closed and the coolant temps max out at 195 with the new clutch fan.  I have an accurate coolant temp gauge.  The ACP Direct Fit radiators truly do fit the factory Ford 24 inch saddle brackets.  The welds on the aluminum radiator are beautiful, and it is a high quality radiator.  I spent $500 for a 20 inch US Made radiator from US Radiators in California 5 years ago.  This new 24 inch radiator is much higher quality than the US Radiator was by a wide margin. 

[tahart]

My car does not have a clutch fan? That could be part of the problem? The fan it has looks aftermarket but is a solid bolt on to water pump with what looks like a 3" extension. What clutch and fan should I buy? The shroud is in place and in perfect condition.

[tahart]

How would adding a clutch to the fan increase cooling at idle over a fan w/o a clutch?

[Side-Oilers]

Be sure to have as deep of a fan shroud as you can fit. Makes a big difference in air-drawing efficiency.

[69 GT350 Vert]

How would adding a clutch to the fan increase cooling at idle over a fan w/o a clutch?

It won't unless you install the proper fan.  If you can bend the blades on your current fan with your fingers, then you have a flex fan.  They do not move nearly as much cfm of air at lower rpms as a rigid, heavy gauge steel, 7 blade fan.  The 7 blade 428CJ fan blade pitch is also deeper, which catches and moves more air.  If you have a FE big block, I suggest you buy a Hayden 2710 or 2711 clutch fan and install a repro or real 7 blade 428CJ steel fan instead of going to electric fans.  Look at the Hayden specs for the proper depth of the shaft you need in your application.  As an added bonus, a proper functioning clutch fan will increase horsepower by reducing the resistance on the waterpump shaft. 

[tahart]

Why did you go with the Hayden 2711? The 2710 is the one that Hayden says is for the 428? Is the 2711 shorter? Clearance issue?

[rockhouse66]

Hayden 2765 is the correct replacement for an original C9Z 428 CJ clutch.  The Hayden catalog is wrong.


https://www.428cobrajet.org/id-fan-clutch

[tahart]

The Hayden 2765 has a 3.25" fan bolt circle, and the Ford 428 seven blade fan has a 3.00" fan bolt circle.  Looks like 2710 and 2711 are the correct choices, with 2711 being a bit shorter. I confirmed with Hayden that 2765 has a 3.25' fan bolt circle.

[69 GT350 Vert]

Why did you go with the Hayden 2711? The 2710 is the one that Hayden says is for the 428? Is the 2711 shorter? Clearance issue?

My car is a GT350 small block 351W, which is why I went with the 2711 Hayden clutch.  I found this info on 428cobrajet.org.  https://www.428cobrajet.org/id-fan-clutch

I have received reports that say that certain aftermarket clutches made by Hayden (catalog available on their web site) will fit. Part number 2765 (1.09" shaft, 3.25" bolt circle diameter, 7.20" diameter clutch body, 2.67" overall height) is supposed to fit with the C9ZE-E fan. This clutch is available from NAPA under part number TEM 261306. Part number 2711 (1.40" shaft, 3.00" bolt circle diameter, 7.20" diameter clutch body, 2.98" overall height) is supposed to fit with the C8OE-B fan. This clutch is available from NAPA under part number TEM 273370.

Here are two pictures (picture 1, picture 2), courtesy of Jim Woods, that show the 2765 clutch compared to the C9ZE-B clutch.

The funny thing is that the Hayden catalog says the correct replacement for a 428 CJ is part number 2710, but in looking at the description in the catalog it's clear that the 2710 will not fit. The bolt circle diameter and height are both wrong. Hmm... 

[69 GT350 Vert]

Rockauto.com shows that 2710 is the correct thermal fan clutch for a '69 Mustang with a 428CJ.  They sell them for $27.79.  Most of the Mustang parts suppliers sell the same unit for triple that price.

https://www.rockauto.com/en/catalog/ford,1969,mustang,7.0l+428cid+v8,1132434,cooling+system,radiator+fan+clutch,6812

https://www.rockauto.com/en/moreinfo.php?pk=1793512&cc=1132434&pt=6812&jsn=15

[Royce Peterson]

The Hayden 2765 is the correct clutch. Recently installed one with a C9ZE fan.

The earlier C80E-B fan has a different bolt pattern.