Doghouse vs non-doghouse fan shroud

A common upgrade to aircooled VW engines is the change from a non-doghouse (or "upright") fan shroud to a doghouse fan shroud. I'll explain why.

Prior to 1971, the oil cooler in an aircooled VW engine was positioned near the #3 cylinder and was housed fully inside the fan shroud. During engine operation, hot air expelled from the oil cooler was released over the #3 cylinder, making it susceptible to overheating and related failures.

VW corrected this in 1971 by redesigning the engine so that the oil cooler sat away from the cylinders and outside the fan shroud in its own "doghouse". This, and some additional pieces of engine tin, ensured that hot air was expelled into the engine compartment and away from the cylinders.

Completing this upgrade is fairly straightforward but requires some special parts. First, you'll need a doghouse-style oil cooler and mounting hardware. The upright oil cooler in pre-1971 engines will not fit in the doghouse fan shroud. Next, you'll need the adapter plate that creates a mounting point for the new oil cooler. Finally, you'll need the following engine tin components: the doghouse fan shroud, airflow tin pieces, and front engine tin (which has holes for the airflow tin pieces).

Although it's not an absolute-must, this upgrade is an important step in caring for your engine and ensuring a long life of service. Of course, here at Postwar VW, we can complete this upgrade for you. Thank you for reading!