Volkswagen Wasserboxer engine

The Volkswagen wasserboxer, abbreviated WBX, is a water-cooled flat four-cylinder boxer petrol engine developed by Volkswagen as the successor to the air-cooled boxer engines of its Type 2 van. It has overhead valves worked by pushrods and rocker arms, a cast aluminium alloy block, heads and pistons, a forged steel crankshaft with four main bearings, and a Heron cylinder head with combustion chambers formed in the piston crowns. It was offered in 1.9 litre and 2.1 litre sizes that share one bore, the larger engine having a longer stroke. Volkswagen made the switch to water cooling in mid-1982 because the air-cooled engines could no longer meet emissions standards. The engine was fitted only to the Volkswagen Type 2 (T3), and some examples suffered water jacket gasket failures.