Did Porsche have to go water-cooled? Options

[thomasotten]

In the late 70's VW decided to go water-cooled, I gather to keep up with emission requirements. Porsche, obviously wanted to early on as well, with their 928 (intended 911 replacement). But, it seems they were able to keep their engine air-cooled way up into the 90's. Yet, they too went for water as well, even though they seemed to have conquered all obstacles. I alway wonder: did they need to? Why couldn't the engine continue to be developed as air-cooled? Materials are getting better all the time, and they actually want engines to run hot for greater efficiency, so why did they wimp out? Opinions?

[Cap'n Krusty]

I understand engine noise levels had something to do with the change. Reaching required emission standards probably had a part in the change, as well, and KEEPING the levels low over the life of the engine, and in all running conditions and modes was certainly a consideration. The Cap'n

[Dominic]

In the late 70's VW decided to go water-cooled, I gather to keep up with emission requirements. Porsche, obviously wanted to early on as well, with their 928 (intended 911 replacement). But, it seems they were able to keep their engine air-cooled way up into the 90's. Yet, they too went for water as well, even though they seemed to have conquered all obstacles. I alway wonder: did they need to? Why couldn't the engine continue to be developed as air-cooled? Materials are getting better all the time, and they actually want engines to run hot for greater efficiency, so why did they wimp out? Opinions?

Late 70's ?? VW had the water cooled Rabbit / Scirocco out in 1974.

One of the reasons Porsche went to the current watercooled configuration was to utilize 4 valve technology.....of course I can't remember where I read that, might have been Bruce Anderson's 911 performance handbook?

[thomasotten]

I understand engine noise levels had something to do with the change.

But everyone loved that sound.

[SGB]

The impetus for the 928 was concern over impending emissions and to a greater degree (appartently, as relayed by Ludvigsen in "Excellence was Expected"), noise. Europe lagged the US in requirements for pollution controls, but not noise controls. By the mid-eighteis, the HP barrier could only be broken with watercooling of the heads (962), and the 3.2 in the 89 carrera was prolly the most efficient air-cooler made. But the HP/KG curve compelled even better. To me, the value of air-cooling is weight savings. At some point, the same argument supports water cooling as well.

[anthony]

Water cooling was the only way to raise the hp per liter. Also, the 911 flat six is pretty maxed out at 3.8L.

Besides emmissions, I think it was also a cost saving measure. The old 911 engine was pretty expensive to construct compared to the new ones.

[smontanaro]

I understand engine noise levels had something to do with the change.

But everyone loved that sound.

In fact, that's one reason I wanted a /6 instead of a /4... (IMG:style_emoticons/default/biggrin.gif)

Skip

[Mueller]

I understand engine noise levels had something to do with the change.

But everyone loved that sound.

There is a differance between "sound" and "noise"..... (IMG:style_emoticons/default/biggrin.gif)

The Cap'n is correct, even the type/size of tires that Porsche and other manufactures have wanted to use has lead to certain models not being legal in some countries.

As much as I like my air-cooled cars, water is better for precise engine control of emissions, you can run higher-compression, the tolerances of the motor can be tighter....any mechanical device is going to work best at a particular temperature, with air-cooling, it is much more difficult to obtain that "ideal" temp with the outside temperature changing all the time and with the loads on the engine changing all the time.

Even Jakes DTM is not perfect...if operated in a very cold climate, the motor might never achieve the correct warm up temps unless changes are made..

[Mueller]

I understand engine noise levels had something to do with the change.

But everyone loved that sound.

In fact, that's one reason I wanted a /6 instead of a /4... (IMG:style_emoticons/default/biggrin.gif)

Skip

that's funny, I've gotten more compliments on my /4 (with header) than the 3.6 air-cooled motor in my 911 (IMG:style_emoticons/default/smile.gif)

[Brad Roberts]

Manufacturing.

I have had several of the new gen engines apart. They are stupid simple. Imagine HALF the pieces that are needed to assemble a 3.6 air cooled engine. NO joke.. they mimicked the Japanese and Chinese when it comes to manufacturing techniques.



B

[Jake Raby]

This is a perfect place to unveil the prototype for my new registered trademark...

It pretty much says it all... The full color version is almost completed.. It'll make awesone T shirt...

[Jake Raby]

This is a perfect place to unveil the prototype for my new registered trademark...

It pretty much says it all... The full color version is almost completed.. It'll make awesone T shirt...

[Brad Roberts]

Ha ha.. you where a Marine huh ??LOL

Lose the eyes with tears and you have a winner!


B

[Brad Roberts]

Now I see the skull!

[thomasotten]

It looks like he's got a tear drop of water coming out of his eye.... lamenting the extinction of air cooled engines? Reminds me of that Indian in those pollution commercials.

[smontanaro]

I understand engine noise levels had something to do with the change.

But everyone loved that sound.

In fact, that's one reason I wanted a /6 instead of a /4... (IMG:style_emoticons/default/biggrin.gif)
Skip

that's funny, I've gotten more compliments on my /4 (with header) than the 3.6 air-cooled motor in my 911 (IMG:style_emoticons/default/smile.gif)

Yeah, but I'm an old fart. Early 911s were the dream cars of my youth. (IMG:style_emoticons/default/smile.gif)

[Mueller]

It looks like he's got a tear drop of water coming out of his eye.... lamenting the extinction of air cooled engines? Reminds me of that Indian in those pollution commercials.

that's not water.....it's OIL (IMG:style_emoticons/default/smile.gif)

[bondo]

I don't know if it's true or not, but I read somewhere that getting 4 valves per cylinder was a consideration as well.

[smj]

It pretty much says it all... The full color version is almost completed.. It'll make awesone T shirt...

Like the man said, "I'd buy that for a dollar!" Lookin' good...

[Matt Meyer]

Did Porsche have to go watercooled, yes.

The amazing thing is they managed to stay aircooled as long as they did. Only a private German company would do that. I morn the passing of the aircooled Porsche engine, but Porsche developed it well past it making any sense.

Assembly, noise, emissions, economy, efficiency, all are better with a modern watercooled engine and have been mentioned above.

Don't forget what happens when aircooled engines run lean. I would think all manufactures selling in the US are using lean burn technology for efficinecy and emissions.

Jake that logo needs to be put on a bowling (or mechanic's) shirt. That'd be worth at least a couple of dollars.