Water vapor cooled 911 - the Rubbermaid Solution

[Grady Clay]

[wwest]

Unless the engine is otherwise already subject to detonation(***) there can be NO GAIN from water injection, internal or external.

*** Timing to advanced, octane to low, compression to high......

[Grady Clay]

wwest,

Please read the thread.
The 'Rubbermaid Solution' uses the latent heat of vaporization in the cooling fan to cool the engine.
The water should NOT go in the engine intake.

EDIT All through this thread people mis-construe what is happening – ignore those responses. They simply didn’t study the posts.
This is all about keeping the cylinders and heads cool, NOT water into the combustion process.


Best,
Grady

[axl911]

Grady,

I see you are in Colorado, and I can see why you need this to keep the cylinder head cool.

I moved from El Paso to Dallas (3500ft elevation difference), and I can see an average of 20F degrees drop in the cylinder head temp measured at the sparkplug.

At a higher elevation, there are much less air moving across the cylinder and head.

[911pcars]

Originally Posted by axl911

Grady,

I see you are in Colorado, and I can see why you need this to keep the cylinder head cool.

I moved from El Paso to Dallas (3500ft elevation difference), and I can see an average of 20F degrees drop in the cylinder head temp measured at the sparkplug.

At a higher elevation, there are much less air moving across the cylinder and head.

Not necessarily disagreeing with you. Not all operating conditions are the same.

Your measured 20ºF drop was only relative to your engine, operating, and ambient conditions. Thus, one cannot make a blanket statement about the validity of a cooling solution based on altitude only. There are more variables than altitude.

Sherwood
Seine Systems > MPC

[manbridge 74]

Hmm, why not flow a fine mist in front of one of the oil coolers?

Wouldn't this allow for somewhat more even cooling with less water use?

[axl911]

Originally Posted by manbridge 74

Hmm, why not flow a fine mist in front of one of the oil coolers?

Wouldn't this allow for somewhat more even cooling with less water use?

Don't think this is more efficient than what Grady suggested. Spraying the oil cooler would cool the cooler, which then cools the oil even more, which then circulates through the oil tank and then to the engine, which then cools the cylinder heads.

Spraying at the engine would get the water to the case, cylinder, and head immediately. The air from the engine fan would disperse the water droplets sprayed well.

I like Grady's solution. Just as Grady said, this method is not the same as water/methanol injection (into the cylinder).

High altitude robs you of power, but also makes your air cooled engine run hotter.

[911pcars]

Originally Posted by manbridge 74

Hmm, why not flow a fine mist in front of one of the oil coolers?

Wouldn't this allow for somewhat more even cooling with less water use?

Yes, but "Less" is a relative term. However, one can use water/vapor cooling for any application requiring low temperature air. For example, our web link in the previous post has images showing water mist cooling for intercooler as well as brake cooling. Other users have installed water mist to lower underhood temps.

For a DIY demonstration, with the engine warmed up and idling (high ambient temp day is ideal), squirt some water on your external oil cooler with a spray bottle while observing the oil temp gauge. For real world results, direct a leaf blower toward the cooler w/the water mist to simulate road speed (assume air can turn corners to get to your cooler).

Sherwood

[gtc]

The heads and cylinders run a lot hotter than either of the oil coolers.

Because heat transfer is a function of the temperature difference, directing the water to cool the heads and cylinders would be a more effective use of the water.

If I am not mistaken, one of Porsche's first uses of water cooling was to cool the heads on 962s.

[911pcars]

Originally Posted by gtc

The heads and cylinders run a lot hotter than either of the oil coolers.

Because heat transfer is a function of the temperature difference, directing the water to cool the heads and cylinders would be a more effective use of the water.

If I am not mistaken, one of Porsche's first uses of water cooling was to cool the heads on 962s.

Water misting for a racing application is a valid solution since races are for a finite time period (or laps).

For street applications, since water storage is finite, water misting is more appropriate for those temp. operating conditions that require borderline cooling, as in full-throttle acceleration, climbing a long grade, pulling stumps or other equiv. conditions.

Porsche 962 used water cooled heads, but did so with a closed circulation system. Carrying enough external mist coolant for an endurance event would be iffy, even the time span between fuel stops. If truck racing, by all means .....

If an engine is operating at borderline melt-down conditions, I would go back to the basic build strategy and review some parameters (e.g. excessive boost, compression ratio, max. revs, cooling system capacity, spark lead, etc.).

S

[gtc]

Yes, I believe that has all been stated already in this thread.

[911 tweaks]

thx Grady for one of your fine example of engineering to address probably the #1 issue when 911 air/oil cooled engines are tracked or pushed hard = the heads & engine get too hot...Thanks again for everything...Bob