Camshaft Engineering Company

Camshaft Engineering has recently introduced equipment for the grinding of lobe profiles with concave flanks down to a radius of 75 mm.

All camshafts designed for nominally flat faced followers result in lobe profiles with convex opening and closing flanks, that is, an egg shaped lobe profile. The majority of camshafts designed for roller, or curved faced followers also have convex flanks but in cases where the roller of curved follower radius is small, the corresponding lobe flanks can be flat or concave. In fact, the cam lobe flank radius is a direct function of the follower radius and the maximum follower lift velocity, in terms of milimeters per degree of cam rotation.

For manufacturing reasons, engine designers generally adopt a cam and follower geometry which will result in convex flank lobe profiles. This is so that the lobes can be machined, then ground with large diameter cutting or grinding wheels, offering economical production. Camshaft regrinding machines have been designed also on this basis, limiting their ability to regrind those cams with concave profiles less than the grinding wheel radius, which is usually in the order of 170mm.

Camshafts which have concave flank profiles were more common in the earlier days of engine design. In the 1920's, both Bentley, and Rolls-Royce ran with concave flank camshafts. Such vintage engine shafts cannot be correctly reground with the normal cam regrinding machines of today.

More recently, in roller follower camshafts for high performance engines, where high lift velocities required to maximise airflow to the cylinders, concave flank profiles are being used. We have also encountered a couple of current production engines running concave flank profiles.

In our computer design of modified lobe profiles for current day roller or pivoted curved face follower designs, we find a limiting factor is the standard regrinding machine's inability to grind less than 170mm concave radius. For these reasons, Camshaft Engineering developed and built the equipment to regrind concave flank camshafts. This has allowed the regrinding and manufacture of vintage cams for the 3 and 4.5 litre Bentley engines, roller racing cams for the Chev V8 engines,and offer aggressive modified profiles for existing roller and curved follower design engines.