Quote:
Originally Posted by tofufi
Possibly, although Aluminium is both stronger and has a better thermal conductivity than Magnesium. I suspect it was partly done for weight saving, as the engine location isn't ideal for vehicle handling 
You can get aftermarket crankcases in Aluminium alloys now, intended mostly for performance engines  . |
Could have been weight saving but also might have been a question of cost. I don't know what the relative costs of magnesium and aluminium were back on WW II when the Beetle was first around but it's possible that magnesium was cheaper than aluminium at the time so they made the various parts out of an alloy to save money. The weight saving would have been a bonus.
Just had a look on Wikipedia to see if there was any reason given on there for the alloy crankcase, nothing obvious although i did discover it had cast iron cylinders.
Maybe Ferdinand Porsche wanted something different for the crankcase and came up with his own reason!
Talking of antifreeze and VW Beetles/air-cooled engines reminds me of a "practical joke" played by someone when i was doing my apprenticeship.
One lad had a Beetle and the person playing the "joke" poured some antifreeze under his front bumper just before it was time to leave for the day and told him he had a radiator leak.
The owner just laughed, got in and drove off, while the rest of us stood there laughing!
The guy who poured the antifreeze under his front bumper couldn't work out why, even when someone explained it was a rear-mounted, air-cooled engine!