Concertina Air-intakes

[Lowlight_Lover]

Hi

Can someone please explain why some aircooled VW engines have "concertina" pipes (sometimes foil-covered) which run between the big fan-housing behind the engine and the bottom engine-tin? I assume this is for better cooling but then why do some of the later (newer) beetles have the pipes blanked-off? Is this a worthwhile mod?

Thanks and regards
Clarke

[dixtoy]

Those pipes are for the heater, it blow air from your fan housing in to your heater boxes that heats the air and then it blows into the car.

If you blank them off you get more air blowing over the heads but then you have no heater in the car.

[Retrobug]

Those are the heater pipes
they run drom the fan shroud to the exhaust system to heat the air and then into the car to heat the driver.

[Retrobug]

Snap
Beaten by Dixtoy

[fig]

As the others said, they duct air over the exhaust heat exchangers so that you can have heat in the car.

They are often removed because the heat exchangers have been removed (and replaced with J-pipes) or the heating system has been disabled due to oily smells or exhaust fumes being pumped into the car.

It's debatable whether blocking the heater ports on the fanhousing improves cooling. It seems logical that diverting cooling air from the cabin heater to the engine would lead to improved cooling, but the heat exchangers have a dual purpose: firstly to provide warm air to the cabin, but they are also significant heat sinks drawing heat away from the cylinder heads, and they are cooled by the air flow through the ducts that you ask about.

[Lowlight_Lover]

Thanks folks, learning all the time...