[S2!!!]

With its EVOII mechanical vacuum pump, Bosch has made the economical mechanical pump lighter and much more efficient, putting it on a par with supposedly more efficient yet far more expensive electric vacuum pumps. The Bosch EVOII costs up to 75 percent less than comparable electric pumps, for modern petrol and diesel engines. In addition, this pump emits less than 0.4 grams per kilometre of CO2 and the unit is contained within the engine compartment.

To realize this achievement, Bosch took its tried-and-tested pump and revised it from scratch. This new generation is 300 grams lighter than other mechanical vacuum pumps, and more than a kilogram lighter than electric ones. The difference being the thermoplastic rotor.

The functional principle of the mechanical vacuum pump has been firmly established for diesel engines for a long time. In recent years, there has also been a growing need for vacuum in modern petrol engines due to the spread of direct injection, which in combination with engine downsizing reduces fuel consumption by up to 15 percent. As of 2013, some 40 percent of all new cars in Europe had direct fuel injection. Modern direct fuel injection systems need an additional pump, since the vacuum can no longer be controlled by the throttle valve.

“With the EVOII, we re-examined an established product and refined every detail,” says Alessandro Fauda, head of development for the mechanical vacuum pump. As a consequence, the product is designed in such a way that it provides the necessary amount of vacuum while still creating the least amount of friction of any product on the market.

The Bosch vacuum pump can be driven by the crank or camshaft, a gear or a chain. It can also be integrated with an oil or a fuel pump.

[Jeroen]

Originally Posted by S2!!!

With its EVOII mechanical vacuum pump, Bosch has made the economical mechanical pump lighter and much more efficient, putting it on a par with supposedly more efficient yet far more expensive electric vacuum pumps. The Bosch EVOII costs up to 75 percent less than comparable electric pumps, for modern petrol and diesel engines. In addition, this pump emits less than 0.4 grams per kilometre of CO2 and the unit is contained within the engine compartment.

To realize this achievement, Bosch took its tried-and-tested pump and revised it from scratch. This new generation is 300 grams lighter than other mechanical vacuum pumps, and more than a kilogram lighter than electric ones. The difference being the thermoplastic rotor.

Interesting. Thanks for sharing. Of course, the pump doesn't emit CO2. So I'm not sure how to read this; does it mean in order to drive this pump a typical engine would emit 0.4grams CO2 per kilometer less then a conventional pump.

Be interesting to see a cutaway version of this pump so we can see this thermoplastic rotor. These vacuum pumsp don't need to create real high vacuum, but still creating vacuum with a rotor type of pump needs some clever engineering. Very narrow tolerances required.

Do these come in one size, or do they come in a different range of capacities?

I have had a lot Bosch components in a lot of my cars over the years and I must say they tend to be very well designed and rarely give any problems.

Also, as a classic car owner Bosch stands out from the others, as they have a special division that looks after some of their old, long out of production, products as well. I can still get my L-tronic injection system of my 1980's Alfa Romeo serviced by them.

Jeroen