Dear friends,


This is a swap and the original fan nor shroud does not fit in.



Fan does not fit

Therefore the only option I have is to go for an aftermarket 3 row aluminium radiator with 38mm inlet/outlet coupled with two 12" electric fans.


Only option available

I have installed an 180 degree thermostat and my plan is to make a short piece metal tube of 38mm diameter with a threaded hole on top to mount this (or similar)


And then connect one side of the tube to the radiator bottom outlet (via rubber hose) and the other side of the tube to the water pump inlet hose.
Then use this temp switch to turn on/off cooling fans via relays.
I am planning to use external ATF cooler (19 row ATF cooler) with a 7" fan.
I will also install A/C condenser in front of radiator with push fans. (will run independent of radiator fans, de/activated with compressor clutch signal)

The temperatures here are usually around 27C and tops 35C. (81-95 f). Lowest possible in the country is 64 f.

My questions are the following:
1. Is this temperature range OK for engine? If not, what is the best range?
2. Should I have the ATF cooler fan always running or turn on/off with the radiator fan?
3. Or should I stop being lazy and get a similar setup for the ATF cooling system for it's fan? If so, what should be the turn on/off temps?

Any other advise are also welcome.
Thank you

 

Put the largest width rad you can put in there. What amperage do those fans draw? The 307 is an easy motor to cool. That temp switch is a fine temperature range. I have gone through a few of those switches and 40 amp relays as well, which are also necessary.

 

This rad suits 1972 350 Chevy. So should be good for the 307. Each fan is 80W so its about 7A each. That switch came for Alfa Romeo 33 boxer engine (if that helps someone)

 

Those are weak fans, the good aftermarket and factory fans draw about 3 to 4 times that much amperage. How wide is that particular rad? A 34" wide by 18.5" tall rad will fit the spot nicely, just make sure it fits the cradle properly.

 

This is only 27" wide because the standard Olds rad doesn't fit between the chassis rails (as this is a swap). The new rad was made to fit the car (as this car came with a Chevy 350). I should re consider the fans then.

 

A large 2 core with 1" or larger cores is the best bet for cooling. A 4 core is also better but is more restrictive to air flow due to being thicker. Those fans might cool engine enough, hard to say, the 307 cools fairly easy. A factory style fan switch should last much better than aftermarket ones. One like this will move more air.
https://derale.com/products/electric...werpacks/dual-
powerpacks/16833-detail
They have many options, one will fit.
https://www.google.com/url?sa=t&sour...JJTab0YvShyTsp

 

I would try what you have and go from there.