Honda C engine

Honda's first production V6 was the C series; it was produced in displacements from 2.0 to 3.5 liters. The C engine was produced in various forms for over 20 years (1985–2005), having first been used in its then new Legend model, and its British sister car the Rover 800-series (and Sterling).

All C engines share in common a 90-degree V from bank to bank. Beyond this fact there is little to no similarity between the three drive train layouts. The engine family can be broken down into three sub families:

As a general rule, interchange of parts will not work between these sub groups.

SOHC 2.0 L (1,996 cc)

Japan only:

The variable length intake manifold used six individual small-bore intake runners below 3,500 rpm for each cylinder and added an additional six individual larger bore intake runners at higher RPMs.

The C20AT was a turbocharged version, called the "Wing Turbo", producing 190 bhp (141.7 kW; 192.6 PS).

Japan only:

Honda replaced the variable length intake manifold with a variable geometry turbocharger to the C20A engine used in the Japanese Domestic Market Legend. The turbo with intercooler-equipped engine was the C20AT engine and are extremely rare. Honda pioneered variable-geometry turbo chargers. The "Wing Turbo", as Honda called them, were controlled by an 8-bit processor ECU and they were constantly adjusting. Basically, at low speeds the wings surrounding the turbine wheel inside the compressor housing on the intake side would be nearly closed to speed and direct exhaust pressure precisely on the turbine wheel. At 2000 rpm, the wings would fluctuate and it would act like a much larger turbo to increase fuel economy as needed. This car was quick and powerful, but the price premium over the slightly longer and wider Legend with the 2.7 L naturally aspirated V6 was too much for most, so the car disappeared. This was one of the only production Hondas ever turbocharged from the factory (excluding turbo engines of kei car for the Japan domestic market), along with the K23A1 straight-4 engine used in the Acura RDX and the ER straight-4 engine used in the first generation Honda City.

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Wikipedia