914/V8 Fan Operation, Conversion Cooling Options

[Andyrew]

Show us a pic of your air inlet. Show us a pic of your radiator shrouding.

You may have air escaping somewhere.

[John2kx]

QUOTE (tyler @ Jul 25 2005, 07:45 AM)

I have a top cover and there is complete sealing to avoid recirculation. After looking at the Renegade pics, I did some testing and found that the side plates to channel the airflow in (removing turblence) and a little air dam in front to force the air up towards the radiator make a major difference. Ran for ~30 miles (about 80 outside)right on 185, fans never came on. I'd like to see pics of what anyone runs for an air dam since I just used a short piece of sheet metal and there must be something nicer looking and more efficient. I didn't see anything in the Renegade pics.

Tyler,

I thought you had the top cover on shroud removed and hood off at the beginning of this thread. If you installed it AND added a small wing to your air dam, I'd be willing to bet the addition of top cover on shroud as reason for improvement. Please clairify.

The switch used to activate fans provided by RH is mounted 6" or so below top radiator hose on radiator. I questioned the on/off temperatures selected for this switch as well and can only say that the boys in Vegas have quite a reputation when it comes to cooling v8 914s. There on/off numbers were selected through much testing in some of the worst conditions. If I was going to follow someones lead, it would be them.

Since the fans don't provide any cooling above 45 mph or so (according to RH), and you have a adjustable switch, you could lower your "fan on" trigger until you reach a point where the fans never come on when in cruise mode. The lower the point the fans come on when you start slowing down or entering bumper to bumper traffic, the faster cooling takes place in addition to providing more consistant water temperature. Also known as the snowball effect, or how to avoid it.

One other note when performing similar tests: always make sure conditions are the same or close. Make the duration/route/driving style the same. Results will be different when driving in 80F vs. 90F weather.

It looks like your armed with all the right tools (fan on/off indication, adjustable fan switch) and are not suffering from high water temperatures. I'd continue to make changes until you see optimum results while experiencing high outside temperatures.

Good luck,

John

[tyler]

John,
You're right, I did make a run with both the top radiator cover off and the hood off. Next I put the top radiator cover on and left the hood off - just as you said it's better since the air has to be guided into the radiator - the hood off was just to check that the fender well air exit cuts were adequate.
It sounds like noone has any kind of inlet air scoop/dam in back of the lower air inlet opening - it seems like it should help so I'll make one, probably short and at about 30 degrees. I post some pics shortly.

[John2kx]

I found these while surfing a little while ago. My car ran a/c and in severe weather here in Ga. without going to this extreme.

Check the RH site again (customer cars). Some of them could not be transferred here.........by me anyway.

John

[Terryst1]

Tyler:

The first question I have is how much HP are making?

In my case I have 383 pumping out about 500HP. I bought a cheap alu radiator for a camaro (31" X 19") from
Summit. Then I made sure that the air intake was 40% of the radiator area, enclosed the radiator in sheet alu to DUCT the airflow and exhausted out the BOTTOM of the trunk, NOT the fenderwells.

I drove it yesterday in 85 degree temps and after getting to 40MPH, I shut off the cooling fans and it ran happily at 180 degrees! The car runs 200 on the track at Willow Springs.

I am running a restrictor washer instead of a T-stat, but will stick in a 180 degree unit some time. Why, because on COLD mornings (50degrees F) the water temp will stay DOWN at 140 degrees!

I have a RennSpeed nose and Spoilers to the ground to KEEP airflow from going under the car.

I hope this is a help,

Terry

[Terryst1]

Tyler:

By the way, I forgot to mention that I have a HEADER TANK that is mounted as high as possible in the engine bay, just under the engine cover.

The larger tube on the bottom of the tank feeds to a "T"
in the water line coming out of the engine, and going to the radiator.

Then in the intake manifold, next the the t-stat hosing,
I fitted a 3/8" BLEED LINE to the top of the tank.

With this setup, the air in the system AUTOMATICALLY bleeds out of the cooling water and collects in the header tank. I am running a standard 15 PSI cap.

When I fired the engine a year ago, I did a basic bleed of the system, then filled the tank to the top, let puke out the excess leaving it 1/2 full and have NEVER had to add water since!!

THIS IS OLD TECHNOLOGY and IT WORKS ......I learned it on my Dad's '64 Cobra! Actually, I am running the SAME tank from the Cobra!!

Best of Luck,

Terry

[John2kx]

Terry,

Your name sounds familar and I think I know who you are. If so, I'm glad to see you on this board. Let's see some pics of that setup.

John