Any successful radiator in engine compartment conversions?, Or other than front trunk installs? Options

[Mueller]

I know this had been tried 7+ years ago, I was wondering if since then has anyone done a watercooled conversion and not put the radiator in the front trunk?

[effutuo101]

So, running an air cooled big 6 gets enough air. Why wouldn't a large 4 get enough with fans?
Inquiring minds want to know.

[Mueller]

So, running an air cooled big 6 gets enough air. Why wouldn't a large 4 get enough with fans?
Inquiring minds want to know.

Exactly, water is a more efficient medium than air so if that compartment can shed 300hp worth of an air cooled* 3.6 it seems that same space can shed the heat from a 300hp 4 or 6 water cooled motor

*anyone have the numbers how much cooling is really done by the oil?

[SirAndy]

So, running an air cooled big 6 gets enough air. Why wouldn't a large 4 get enough with fans?
Inquiring minds want to know.

Exactly ...

No, not exactly ...

On the air cooled engines, there is a clear separation between the intake side of the engine and the underside where the hot air is expelled.
Without that separation, our aircooled engines would be very short-lived.

I have yet to see any watercooled solution that followed the same principal.
(IMG:style_emoticons/default/shades.gif)

[Brian Mifsud]

So, running an air cooled big 6 gets enough air. Why wouldn't a large 4 get enough with fans?
Inquiring minds want to know.

Exactly ...

No, not exactly ...

On the air cooled engines, there is a clear separation between the intake side of the engine and the underside where the hot air is expelled.
Without that separation, our aircooled engines would be very short-lived.

I have yet to see any watercooled solution that followed the same principal.
(IMG:style_emoticons/default/shades.gif)

Adding to this.. the 911 engine uses Mechanical Energy to run a Centrifugal Blower.
It moves MEGA cubic feet per minute by sacrificing many horsepower. Estimates are up to 16HP:

http://forums.pelicanparts.com/porsche-911...g-fan-cost.html

Think about how big a 16HP electric motor is...

In a 914, you need brute force to pull the air down and through the engine bay.

I think this is the fundamental reason why a front mounted radiator is far more efficient.

[Mueller]

Adding to this.. the 911 engine uses Mechanical Energy to run a Centrifugal Blower.
It moves MEGA cubic feet per minute by sacrificing many horsepower. Estimates are up to 16HP:

http://forums.pelicanparts.com/porsche-911...g-fan-cost.html

Think about how big a 16HP electric motor is...

In a 914, you need brute force to pull the air down and through the engine bay.

I think this is the fundamental reason why a front mounted radiator is far more efficient.

hmmm, maybe we are looking at this the wrong way....perhaps it should be suck and not blow? (IMG:style_emoticons/default/screwy.gif) (IMG:style_emoticons/default/av-943.gif)

Radiator setups with pull type fans are more efficient than those with pusher fans...

[Brian Mifsud]

hmmm, maybe we are looking at this the wrong way....perhaps it should be suck and not blow? (IMG:style_emoticons/default/screwy.gif) (IMG:style_emoticons/default/av-943.gif)

Radiator setups with pull type fans are more efficient than those with pusher fans...

Somebody already did the work years ago either on this forum, or on "Rennlist", but it's very useful to understand where the Vacuum is in and around that engine bay at speed. Typically, you'd expect a low pressure area behind the rear window due to the sudden transition of the roof ending at the engine compartment "intake".

Under the car, the little skirt Porsche put in front of the bottom edge of the engine compartment is supposed to do the same thing, create a low pressure region to help "pull" the air through the fins as pumped by the engine's scroll/squirrel cage blower. I've always wondered which area had a lower pressure "vacuum" at a given speed.

I don't see a compelling reason for air to flow through the engine bay on it's own without being pumped in some manner. Years ago, at an autocross, I had to laugh at the racer's solution.. taking furnace ducting, and running it straight through the front of the car, trunk, passenger compartment, and ending aimed directly at the blower which had blades removed to minimize parasitic drag and lost HP. The car's sheetmetal was certainly hacked up. Now THAT was taking the bull by the horns....

[Dave_Darling]

...taking furnace ducting, and running it straight through the front of the car, trunk, passenger compartment, and ending aimed directly at the blower ...

That's the road-race solution. It stems from rules that were originally written for Little British Cars--you were allowed to duct air from the headlight buckets to the cooling fan.

Works well at speed, but not so great at idle or at low speeds.

I talked to the late Chuck Forge about it, and the cooling fan with most of the blades removed. He said he ran a full fan once to compare--and it felt like he was dragging a trailer around the track with him! Chuck used fans with, I think, 2 out of every 3 blades removed. I remember Rich using fans with all the blades removed. Probably one reason that Rich quoted higher power levels than Chuck did.

--DD