1600 GTA crankshaft - manufactured by Arrow precision, a leading UK crankshaft manufacturer with over 30 years experience in the Motorsport arena, including Formula 1, Le Mans, WRC and WTCC. They are manufactured to a specification that has been developed over a number of years by a German Alfa Romeo engine specialist and is the result of extensive experience of tuning the 1600 GTA engine.
The cranks are manufactured from a solid billet of very high specification EN40B (722M24) material. The material is specially selected to ensure that it is particularly clean ensuring that oxide and sulphide content is minimised. This gives major improvement in the strength and ductility of the material and greatly improves fracture resistance. Our material should not be confused with other (cheaper) steels that are used in crankshaft manufacture!
The design incorporates eight counterweights to increase reliability at high rpm by reducing the loads on the crank bearings generated by the connecting rod and piston inertia. The counterweights are knife edged to reduce drag and are pocketed to remove inefficient mass, helping to reduce overall inertia and improve throttle response. The oil supply galleries are fully linked through the crank and feature new outlet positions in the big ends to optimise the supply of oil to the connecting rod bearings.
The crank is gas nitrided to increase the hardness of the bearing surfaces and dynamically balanced to race engine specification. We firmly believe that you will not find a better crank on the market!
Can be used in normal 1600cc 101/105 series engines as well.