Thermostat or No Thermostat?
I may have missed it, but what size is the radiator? Not because it's the problem, just because that controls the size of the fan you can use.
A 2,400 cfm fan is pretty borderline for moving enough air. The fact that the shroud doesn't cover the entire radiator is a problem too, you're only cooling the part of the radiator that the shroud covers with the fan. It also depends on how the fan is wired. If for some reason it can't pull 100% of the power it needs, it isn't putting out that cfm rating. It should be set up off a relay with pretty heavy gauge wiring.
I run a Ford Contour dual electric fan on my Duster. That works with a 26" radiator, and covers the entire shroud. It's capable of 3,500 cfm on the low speed setting, and ~5,000 cfm on the high speed. It does a great job of cooling my .060" over 340, which has ported iron 308 heads, a lunati 60404 cam, 9.8:1 compression, headers, air gap intake, etc. Most of the time the low speed is all that is used, although a few times I've had the car out in the 110*F heat we get here on occasion the high speed has kicked on. The fans on my car are controlled with a Dakota Digital controller, with a dual relay set up.
My install is here [URL="https://www.forabodiesonly.com/mopar/threads/my-new-74-duster-or-why-i-need-a-project-like-a-hole-in-the-head.198098/page-3#post-1970313646"]My "new" '74 Duster- or why I need a project like a hole in the head[/URL]
If you do have a 22" radiator still, you can look into using a Ford Taurus electric fan. It will fit on a 22" radiator, and although it's a single fan it does have two speeds, and will move substantially more air than your current fan. I prefer using OE electric fans vs. aftermarket, they were engineered to go 100,000 miles or more on a car that has a factory warranty. With aftermarket stuff, some are good, some are definitely not.
I may have missed it, but what size is the radiator? Not because it's the problem, just because that controls the size of the fan you can use.
A 2,400 cfm fan is pretty borderline for moving enough air. The fact that the shroud doesn't cover the entire radiator is a problem too, you're only cooling the part of the radiator that the shroud covers with the fan. It also depends on how the fan is wired. If for some reason it can't pull 100% of the power it needs, it isn't putting out that cfm rating. It should be set up off a relay with pretty heavy gauge wiring.
I run a Ford Contour dual electric fan on my Duster. That works with a 26" radiator, and covers the entire shroud. It's capable of 3,500 cfm on the low speed setting, and ~5,000 cfm on the high speed. It does a great job of cooling my .060" over 340, which has ported iron 308 heads, a lunati 60404 cam, 9.8:1 compression, headers, air gap intake, etc. Most of the time the low speed is all that is used, although a few times I've had the car out in the 110*F heat we get here on occasion the high speed has kicked on. The fans on my car are controlled with a Dakota Digital controller, with a dual relay set up.
My install is here [URL="https://www.forabodiesonly.com/mopar/threads/my-new-74-duster-or-why-i-need-a-project-like-a-hole-in-the-head.198098/page-3#post-1970313646"]My "new" '74 Duster- or why I need a project like a hole in the head[/URL]
If you do have a 22" radiator still, you can look into using a Ford Taurus electric fan. It will fit on a 22" radiator, and although it's a single fan it does have two speeds, and will move substantially more air than your current fan. I prefer using OE electric fans vs. aftermarket, they were engineered to go 100,000 miles or more on a car that has a factory warranty. With aftermarket stuff, some are good, some are definitely not.
