what are the basics of mechanical injection, trying to learn the basics and what does what Options

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[Dave_Darling]

The Bosch pump setup in the early 911 and many of the Porsche race cars is derived from a diesel fuel pump setup. The pumps are set up like little engines, with one piston per cylinder of the engine. The piston pushes the fuel at high pressure into the fuel lines, sending it to the injector.

The pistons in the pump are asymmetrical, and push more fuel when turned one way and less when turned the other. Mixture control is done by turning the pistons in the pump. They are all turned together in response to throttle position and engine temperature. The temperature is provided by a heat riser from the exhaust, or an extra "leg" from the heat exchanger. (The race car versions did not have temperature compensation; a crew-member had to physically hold a lever in the "cold engine" position during engine warm-up.)

Here's an article about the diesel pumps that the Bosch setup is based on: http://en.wikipedia.org/wiki/Injection_pump

--DD