The wasserboxer features a
cast aluminium alloy cylinder block,
cylinder heads, and
pistons; and a
die-
forged steel flat plane crankshaft with four
main bearings. As in Volkswagen's earlier air-cooled luftboxer engines, the wasserboxer's three-bearing
camshaft is driven directly from the crankshaft by means of a small steel gear on the crankshaft and a larger aluminium gear on the camshaft, with the whole mechanism internal to the engine. The
overhead poppet valves each feature two
concentric valve
springs, and are operated by pushrods and rocker arms, which are adjustable to facilitate setting valve clearances. The wasserboxer also features a "
Heron cylinder head" with "bowl-in-piston" type
combustion chambers, in which combustion takes place within the piston area rather than a recess machined into the cylinder head. The
cylinder banks consist of
cast iron cylinder liners inserted into the
crankcase surrounded by a
water jacket, with a "rubber lip" style
water jacket seal. The tops of the cylinder liners are pressed into recessed cut-outs in the cylinder heads and sealed with compressible metal rings to prevent leakage. The wasserboxer was available in two
displacements — 1.9-litres and 2.1-litres. Both engines have the same
cylinder bore, but the 2.1-litre has a longer
stroke. Some wasserboxers suffered from water jacket gasket failures, often erroneously referred to as head gaskets. Some design decisions, such as poorly placed sensors and a cooling system prone to leaks, may have made the engines more likely to experience this type of failure. Other possible explanations have focused on corrosion in the cooling system, and the use of phosphated coolant. The switch to water-cooling for the boxer engines was made mid-1982, because Volkswagen could no longer make the
air-cooled engines meet
emissions standards. The wasserboxer engine was only used in the
Volkswagen Type 2 (T3). The previous generation
Volkswagen Type 2 T2 was produced in Brazil until 2013, and changed to water-cooled
Audi-sourced inline four engines on 23 December 2005 in response to Brazil's emission laws. ==Variants==