DELTA_Rotary

I think my next project is going to be a rock crawler with a 13B. One of the big problems I see is cooling the rig with little to no airflow. Maybe a water to air intercooler and a radiator with some big fans (Most likely re-located to the back of the rig) is all I got right now. Any ideas?

TomU

iTrader: (11)

Electric fans and water pump

peejay

My RX-7 is a similar problem: 270hp, used at speeds mostly below 40mph, for a minute or two at a time. Radiator space is limited in the nose of an FB so I could not go much larger than the stock 22x19 radiator size, so for simplicity's sake I just use a radiator actually intended for the car.

Two things I had to combat were water pump cavitation and airflow. Cavitation is easy: underdrive pulley so the water pump doesn't stall. The common pump setups for V belts will stall at 6000 or so, depending on what combination you have, so a run spent mostly between 5000 and 8000 would result in bulk overheating. Also belt wear was rapid because when the pump cavitates, it puts shock loads on the belt, and the belt routing glances the water pump off of the slack side of the belt at a low amount of belt wrap. If you are not going to be revving the engine high for extended periods of time, stock pullies should be fine.

As for the airflow problem... I sourced a fan assembly from a Chrysler 300M. Front drive car with a small radiator, a thick cooling stack for poor airflow in, and an engine right up against the radiator for poor airflow out. These fans are BEEFY. The fans on low speed will draw a tad over 30 amps and on high speed will draw a tad over 70 amps. But they work! I could do dyno pulls and not see a coolant temperature rise during the run.

If you have the room, I'd use a radiator and fan from a '13 Mustang GT500. That is fairly inexpensive, fairly easy to swap (fan attaches directly to radiator), and the fan pulls a phenomenal amount of air for the current it draws.

mustanghammer

iTrader: (3)

Biggest radiator you can fit, good oil cooler(s), electric fans on all of it and blow air on the carb/intake manifold.

I have a 26x19" double pass Afco radiator and use two OE style oil coolers plumbed in parallel to keep my race car cool. Also have the under driven water pump. Some of the guys I have raced with have also fitted a 3" inline blower to blow air on the carb/intake to help avoid vapor lock. The later could happen as a result of a black flag all situation which brings the whole field to pit lane. Rotaries hate that stuff.

peejay

For the 12A I am putting together, the rules are fairly restrictive in what you can and can't do. The rules don't say you can remove the air pump, but you can use any intake manifold. I plugged the coolant passages in a '79 intake manifold, and am using a gutted air control valve so the air pump constantly pumps air through the passage that originally went to the heat exchanger.

That passage is shaped like a large cooling jacket wrapped around the backside of the primary and rear secondary ports. I figure, this will make for forced air cooling of the intake manifold.

At the very least, the air pump belt will ensure that the water pump never slips.

(I am also retaining the air conditioning, which I can technically remove since it is dealer-installed and not factory-installed. Driver cooling is even more important than intake manifold cooling, I'll take the weight hit!)

gunpilot64

Besides the intercooler blocking most of the air, the small fans did not do the job on their own to cool my car. I added a trunk tank that has 2 heater cores installed inside it. The radiator is still a closed system, but I add water in the tank to surround the heater cores. This allows for liquid to liquid cooling. I can also use a pump to circulate the warm water out of the tank to a separate radiator fan set up. This basically gives me more cooling volume to work with.