As a demonstration of how the market is shifting to include new products developed to tackle the technical challenges of ever-changing engine design, original equipment (OE) manufacturer and system supplier, Dayco, earlier this year introduced the auxiliary belt tensioner and water pump friction wheel drive for the PRINCE BMW PSA engine into its aftermarket programme.
To further assist independents compete with the franchised dealer and allow them to carry out a full and complete repair, including replacing the auxiliary belt, the friction wheel is now available as part of a Dayco kit, which contains all the components necessary for each particular model.
One of the most interesting characteristics of this power plant, is the system that controls the water pump, which is activated only when the temperature of the engine needs to be controlled.
Dayco designed, developed and manufactures for OE fitment, both the unique single-arm torsion bar tensioner, which replaces the traditional spiral spring tensioner on the auxiliary drive system and the motorised ‘switchable’ friction pulley that actuates the water pump.
At start-up, or whenever the engine is operating below its optimal temperature, the water pump is disengaged, which decreases the engine’s warm up time, reduces its overall emissions and improves fuel consumption.
However, once the engine reaches a predetermined temperature, the friction wheel is activated, and the water pump engaged, therefore allowing the engine to optimise its thermal management.
To prevent excessive acceleration forces on the bearing during off-on operations, the friction wheel is in constant contact with the crankshaft pulley, but with the use of an electric motor and small planetary reducer, which works in conjunction with a multi-function control system, the pulley’s radial movement is altered, and the rotating friction wheel comes into contact with the surface of the water pump pulley and thus the water pump is brought into operation.
Due to the confined space around these components, a traditional auxiliary belt tensioner could not be employed, which therefore required Dayco to design another innovative solution, this time in the form of the single-arm torsion bar tensioner for the auxiliary drive system.
The Dayco friction wheel is worldwide protected by patents.
One final note for technicians, comes with the fact that early examples require an additional electrical connector, which is only available from BMW.
For more information about the OEM quality power transmission products in the Dayco range, click ‘more details’ below.