A hood ornament (not for the squeamish)

[Ex-MA Hole]

Tradition.  Up until a few years ago Porsche used an air-cooled engine in the 911.

Chris

Why mess with what works for you?  It worked for them for years and years....it's a shame they switched....

[mtnbkr]

Why mess with what works for you?  It worked for them for years and years....it's a shame they switched....

Not saying they should, just saying it's their motivation.  I miss the sound of the old air-cooled engines, but I do believe the new waterpumpers are stronger, quieter engines.

Chris

[freedom lover]

Tradition.  Up until a few years ago Porsche used an air-cooled engine in the 911.

Chris

Thanks. The 911 and 914 did have oil coolers.

I have a question for you cars guys, since my Google-fu is weak. I'd like to know if oil cooled engines have channels in the block for the oil to run through like water cooled engines do. 

[mtnbkr]

No, oil coolers were used to keep the oil temp reasonable in air cooled engines, not for primary engine cooling.  The oil still traveled the engine in the same manner as the oil in a water-cooled engine.

Also, for what it's worth, air cooled VWs (Beetle, Kharman Ghia ,etc) had air cooled engines equipped with oil coolers.  Some folks even installed auxiliary oil coolers in hot running engines or hot climates.

Chris

[AJ Dual]

That seems like it's a very efficient system. You have to pump the oil anyway, and by cooling it through it's own radiator, you're taking the weight and expense of a separate water cooling system out of the equation. Plus the parasitic losses from a water pump as well.

I guess there must still be huge advantages to a water cooled engine for it to dominate so thorougly in the modern automotive world.

[mtnbkr]

Watercooled engines are more efficient.  You can run them at higher compression ratios for a given octane level, the parts can fit together more tightly (effects oil consumption), etc.  Also, the watercooling keeps them at a more consistent temperature regardless of the season.  My Bug was kind of finicky in extreme cold weather (below 25deg) and I tried to take it easy on extremely hot days (above 95deg).

Aircooled engines are pretty simple, but you have to pay more attention to oil temp/pressure, ambient air temp, keep the engine clean (affects cooling), etc.  I never had a problem with my Bug overheating, but I was anal about keeping the oil topped off (never let it get more than 1/2qt low), the engine clean, and I had a mechanical oil pressure gauge so I could monitor the lubrication system.  I would go on Bug-Runs in the mountains, during the summertime, and not have overheating problems that my fellow drivers would experience. 

Chris