My next offroad project will be a gen 1 brat with an EJ22 and a REAR MOUNTED RADIATOR located roughly where the tailgate would normally be.I am wondering if I should have a fan blow air on the engine at slow speeds.I know that most of the cooling duties are done by the coolant system,but I am just wondering if a fan circulating the underhood air at slow speeds would be beneficial or even needed?

 

With the radiator in the bed,the engine will be visible behind the grill.I will also have an oil cooler mounted behind the grill,but that should help rather than hinder.

 

On my hatch with an EJ22 it always ran abit hot until I vented the hood.So I am wondering if a fan might help.The hood on a Gen 1 brat has some functional vents so that should help.

I would say a bit of air movement under the bonnet can only be a good thing.  The oil cooler won't be any good without it anyway...

Cheers

Bennie

You can't go wrong with too much airflow.  Another idea would be to modify the engine bay to allow for hot air to escape easier.  I used to run a Jeep Cherokee with the 4.0 and had to modify the hood by spacing it up in the rear by the hinges to allow hot air to escape.  Made a world of difference.

Dual fans are pretty much the norm on relocated radiators

Dual fans are pretty much the norm on relocated radiators

^^^ What brian said .. every rig I've seen with a radiator relocated in the bed had dual fans mounted to it .

I know about the fans for radiator Im just curious about a fan up front to circulate the air around the engine.

 There is really no need.

Just because your guage said things were running a bit hot, does not mean they were. Unless you shot it with a temp gun and Know for a fact it was running at the indicated temperature.

 

You are over thinking it. Cross that bridge IF you get to it.  It is really simple to go to a yard and get an extra fan....

just start building already.

cheers

I want to. Ive been trying to clean up my house to keep the city off my rump roast. got a few cars and misc parts I gotta clean up.Including playing musical cars while swapping out sets of tires from one rig to another to make them rollable..

So in preparation for this I have been reseaching radiators. I found out that a 74-86 SB chevy pickup radiator would work pretty good because its all metal, and has 1.5" inlets,and more importantly it can be found in evey junkyard in america.I am wondering if it might overcool the engine because once the tstat opened the water from the radiator would be 20* cooler and close the tstat again.I know in general a too big radiator shouldn't overcool an engine but what about when the radiator is for an engine with 3x the displacement and 3x the horsepower?

Nah should be fine - have the fans hooked up for when the sender on the engine or ECU wants it - I definitely wouldn't have one in the radiator!

The thermostat won't instantly close, it'll reduce the amount of flow into the engine (EJ setup) enough to maintain a good operating temp.  If it doesn't work as required go with a smaller radiator or insulate the return pipe from the rad to the engine/run one thermo fan etc etc.

Cheers

Bennie