Just curious... Why did Porsche use horizontal fans on some of its race cars?

Just a guess but - even cooling, lower profile, easy to secure, looks cool.

Equal amount of air to all cylinders ...

Added & more effective engine bay cooling primarily, as the 917 also had the vertical fan on the front of the motor IIRC.

?

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I need a wet-wipe

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If you think about it, what better place to put a cooling fan?

Here's a question. How did they power those horizontal fans?

The 917 had a shaft coming off the crank.

I think I have a cut-a-way drawing of one if I can find it.

Corvair had it and used a belt drive.

917 engine...

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http://www.pbase.com/917carl/917_12_cyl_engine&page=1

Hmm,
Porsche,
Horizontal fan,
Belt drive,


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I had (that engine in) my car idling Sunday with all the head temps within a 5 degree temperature spread.

They suck harder!

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That was the 908 that had the vertical fan.
Anyone make a horizontal fan for the 911 motors? . Not like it'd be in my budget anyway.

How about a type 587 fan on a type IV engine.
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There's a company in europe which makes a repro of the 962 horizontal fan.
Its gear/shaft driven off the nose of the crankshaft.

I have a horizontal fan 911 engine cooling system on my long list of products to develop, to be done sometime after I complete my Type 1 cooling system.

I believe that some of the 935s also used horizontal fans. That may have been in part to make room for charge coolers? Not sure.

They were driven by the standard belt off the crank nose, which spun a shaft with bevel gears on it that spun the fan. Lost significant amounts of power when compared to the belt drive of the 911 fan, but the extra cooling was worth it in an endurance racer. And may have allowed them to run a bit more boost...

--DD

....

Who makes that system & How much

Thanks Bill D.

Not sure why, but I love this look so much !!! Some day I hope to have that Tangerine set up on my 914-4 big bore engine and a matching Tangerine exhaust.

Here are the parts for the 911 set up (less the alternator). This was up for sale a while back. I pondered loong and hard, but could not justify the cost (something like 5-6k as I recall). I love that look.

I think on the 917. it also made sense to pull the air in from the top of the car, as trying to get the air into the front of the motor would've proved difficult to do. On the 914 we have the two small diverters on the bottom of the floor pan (back of the pan) and an area above where the grill is. I wouldn't imagine those are great places to grab air on the 917.

And that 911 setup looks superb. Didn't Jake have a horizontal fan setup available on his big IV's?

No.

Its a home made unit.

Ah, what the hell do you know!

I was thinking of the concept, not the exact application. I guess a horizontal cooling fan is providing a similar airflow path to the DTM setup you use, isn't it Jake?

I liked Darrell Zipp's hand built Type IV cooler in his 550 replica:

I always liked the story (urban legend, or in this case, track legend) about how during the early stages of the 917s' development, that horizontal fan somehow became "'unfastened" and probably landed in another European zip code.

That reminds me of the story about how when Brian Redman was first introduced to the challenge of driving the 917, when the wiper switch was activated, the wiper flew off!
Poor Brian no doubt wondered what else wasn't torqued down properly.

This looks over engineered. I bet we could do it cheaper and better.

Cool, though.

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That looks light

I'm thinking it'd be a damned sight lighter if a bunch of that aluminum was swapped out for CF. I know a guy, just built a new vacuum pump for his layup bench

BMW motorcycle rear 90 degree shaft drive unit.
Bolt to top of case...add fan and pulley.

Just saying...

Rich

Still way to heavy. Why are these things so heavy. A simple shaft and small 90*, enclosed, lubed gear set ought to do the trick. Aircraft style - simple + light.

needs to be high speed
I found a few industrial 90 degree drive units...McMaster sells them.

I thought the stripped bmw unit might also be a valid candidate...I just have not had the time to look at the older ones that would be smaller and lighter...60-70's

Rich

I am considering upgrading the cooling system on my -4 since it gets so hot down here in the summers. I know Jakes DTM is tried and true but I really like the look of Tangerine's horizontal setup. That things got to look damn mean with the engine lid up. Any benifits to one or the other?

I dont know cooling temp numbers nor cost comparisons, but both systems have benefits.

Call Chris and ask him...

Rich