SO .... after way to much time dickering with this car... (74 teener w/ej22 and overhead radiator in the engine bay) I had finally decided it was time for a serious shake down. The Wife and I had planned a white water rafting trip outside of leavenworth. So we saddled up in the Porsche and took off. What a fun car to drive around !! Most importantly I wanted to inform any other subaru or other water cooler converters. I wanted to mount my radiator in the engine bay. I mounted it above the engine where the stock engine bay lid would be. I used the stock radiator from the legacy I gutted. I built some shroud pieces out of fiberglass. Now the important part to think about here is how air flows in the engine bay without the divide created by the engine sealing tin. I figured modestly with minimal research that the engine bay may maintain some of its stock air flow theme. I figured air would flow thru the radiator now where the stock engine lid was. Air actually flows thru the engine bay up thru the lid area when there isn't a fan pushing air thru a sealed motor and out the bottom. I had wired my fan to pull air thru the engine compartment and out the bottom. This lead to an awful overheating problem when it came time for the mountain pass. The motor would get warm. the fan would kick on ... and create air turbulence. and decrease cooling. so you pull over ... let the fan do its trick. and then motor on for five more miles.

This sucked.. I hope someone can learn from this. I wonder how effective a puller fan would be wired up as a pusher? That and maybe a slightly bigger radiator might help.. this stock suby radiator is kinda crappy. single core alum with plastic side tanks.



Ill try and get some pics up but my camera is missing in action..

Congrats on a shake-down run. Besides the cooling issues, what were your impressions of the new powerplant?

The rear radiator has been done and done. I do not know of a true success yet. I'm waiting for someone to use 996, Boxster or Cayman dual rads and see if it works. The natural flow of air is from the bottom - up. So if you push your ait up and out, you may have more cooling ability.

Even if you can get it to cool enough for normal driving, I'm not sure you will have the "Delta T" for spirited driving.

With a dual system and ducting through the quarters, I think you could succeed. Porsche does it for the new models.

On my first V8 conversion, I had a custom flat radiator made. The top of the shroud was just lower than the top of the bumper. It was horizontally mounted on the bottom of the front trunk. Air exit down. It worked great and allowed for a front trunk albeit smaller. The only problem ever was driving slow on a dirt road. Dust would blow up from under tha car and get everywhere.

My new system is all radiator and oil cooler in the front. Just enough room for a fuel pump and battery.

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Im still trying to work logistics in my head to have cooling enough to cool a v8 and still keep 75% of the front trunk... I have some idea's, but I havent tried anything just yet.
Sure it would be easy to get two honda half radiators and cut the sides of the rear quarters out and duct through them... But I would rather come up with a solution that would keep the lines of the 914.



In honesty I want another test car to try it on Have to convince the fiance of that one and I dont think it will go down to well. lol

BTW, most fans run well as either pusher or pullers. If they are aftermarket.

I've been kicking this idea around in my head too! I want to see some pics as I plan to mount my radiator to replace the engine lid too. I would think that you can wire the fans to suck air out of the engine compartment at high speeds, and blow cool air in at low speeds or when stopped. You would control the direction with a switch. Here's a diagram of a circuit that would work. Just use a non momentary 3 position switch,, and hook your fan up to where it says window motor.

-Robert

Hey guys I really appreciate the thoughts back from you guys. Firstly, I have no previous motor exp as the car came with most of its FI in pieces and a low compression hodgepopge of a 1.7 out of an earlier car with bus heads on it. So my chances of getting that to run with out serious money was impossible. although being a previous type 1, type 2, owner I almost yearned to see what a lightweight aircooled motor was like in this car I had been down the aircooled road... infact still have aircooled bikes. SO that being said I sadly have never driven a stock 914, I'm sure Jon Bovey(peegreen) will make sure I know the difference some day. Now the motor in it right now The Ej22 is something else, having played with semi hot rodded type 1 motors I know that a vw motor can get moving, but this motor combo seems to be the cheapy elite formula for building a car that won't instantly destroy the stock drivetrain. Running very open exhaust and cold air styled intake with stock legacy ecu the fueling could be a thousand times better (I need a megasquirt badly, anyone got a half started megasquirt kit that never finished?) Granted closed loop cruizing is pleasant. A person with a well tuned butt dyno can feel the slightly off fueling in quick accelerator action to full throttle. all this aside I LOVE THIS CAR. The motor has plenty of passing power at freeway speeds, plenty of low end torque lugging around at 1800-2000 rpm.

Now I originally wanted to go down the road of engine bay cooling because I loved the versatility of having a car with a frunk. so that is why i have been stubborn and screwed around with this setup and didn't go to more tried idea. I love the thought of two littler radiators like a 996 or cayman. I actually thought slightly of it when looking at a spare crashed on ducati 996 radiator in my garage. If I could find some small radiators that would do the trick i would give it a shot. I don't really wan't to make something custom as its all experimental and may not work and I don't have a budget so I have to work on stuff out of the garage to make 914 money. But this may be the evolution of my design to have two radiator sealed off to the sides of the motor sitting between the intake runner and ends of the engine bay. with a shroud that goes inbetween the two radiators to hide the motor.

Andyrew Dude good luck. I think with some trick fiber glass and a big radiator that fits just right, and some math as to the size of entrance to the radiator vs the exit of airflow and it could be done.

Now the switch fan polarity would be cool in order to change the flow for different speeds. What would be even cooler would be to have a logic circuit hooked up to a speed sensor that would do it for you. I have no idea how to build said circuit .... but a thought.

I think currently I will play around with changing the fan around. Building some fiber glass shrouding in the engine bay under the radiator to influence more air up thru the bottom and out thru the radiator. also there are other things I should do to increase ability to cool. I was running straight distilled water no coolant. I'm sure that most coolants help increase the cooling transference capabilities of water. and to get more crazy there is always water wetter. Now I will admit I worry about spirited driving in the mountains which is by the way all too much fun, granted i noticed if i was in a more agressive driving mode going up the mountain it seemed to take longer to heat up, higher engine speed = higher water pump speed + more airflow. It was really putting up the hill in 5th behind motor homes that made it wan't to boil. Anyways thanks for chipping in.

I'll keep you guys posted. sorry about the novel of a reply here... just have a lot on my mind I guess.

Coolants actually reduce heat transfer efficiency of water. The only thing that will increase it is Water Wetter as you mentioned.

The natural airflow in the engine bay is from the bottom up through the top. The targa bar creates a no/low pressure zone where the engine lid is and actually doesnt push any air down engine lid at speed. Most radiator fans become absolete at ~ 40mph when airflow of the vehicle takes effect. So if you just reverse the fans you should be good in that concern.

Show us your engine compartment, You should be able to do some shrouding under the car to help pull air into the engine compartment. One subaru guy had his radiator in front of his engine, pulled air from under the car, and had about 3" in front of the radiator for the air to get pushed into the radiator from under the car (shrouded of course), then the air went over the engine. Scott Thatcher IIRC.

http://www.914world.com/bbs2/index.php?sho...=suby&st=40