Cosworth Camshafts

Cosworth powered Lotus Formula Junior car.

Followed by the Ford Cortina GT cam and Lotus L1 and L2 cams, the standard was set for performance and racing cams of the day. Over the years, camshaft development continued from Formula One through OE development and everything in between. The innovations achieved continue today and Cosworth is at the forefront of camshaft design and manufacture with the latest lobe design and profiles ensuring efficient and substantial gains in power and performance. Cosworth's world class manufacturing center, located in Northampton England provides camshafts for a wide range of engines including motorcycle and racing applications.

Cosworth manufacturing center

Cosworth Camshaft Development

1. Once it's determined that we are going to offer a camshaft for a particular engine, we determine the sizes of a potential cam lineup based on practical knowledge and experience, performance targets, and sometimes customer demand.
   

2. Next we gather all valve train component measurements such as spring seat pressure, spring pressure at various valve lifts, retainer to stem seal clearance, physical lobe clearance (if tappet bucket head), tappet bucket diameter, valve train component mass, etc. This is especially true if we are going to be offering drop in cams. If an engine has any questionable components, then these components are sent out to our laboratory for a material analysis.

 Valve train dynamic simulation

3. Next we run various detailed calculations for maximum acceleration, velocities, valve spring stress, oil film thickness, and max RPM.   

4. A proprietary piece of Cosworth software then helps us to select from a substantial database of grinds with various duration, lift, and ramp combination using data from the calculations in step 3.
   

5. If the cam profile meets all the criteria a camshaft will be manufactured with the new profile and will be installed into an engine to determine whether it meets the engine performance target. If the target performance is met, additional camshafts will be manufactured and tested to validate the components.
   

6. The first validation test is the high speed valve control check. This involves measuring the valve displacement at high engine speeds. This test is to determine if there is valve float and bounce. If the valve is in control over the new profile, this test will be followed by a scuff test. This is running the camshaft at low speed with new tappets for a reasonable length of time, ensuring the lobes don't scuff during early life. After the scuff test the same cam will do a high speed fatigue test. This is running the camshaft at maximum engine speed for a long period of time. This will show any pitting of the cams if there are any follower/lobe material compatibility problems.

 Nissan VQ35 Camshaft validation test

Cosworth Camshaft Production

1. Cosworth camshafts are ground on Induction hardened, cast or steel blanks. 
   
2. To ensure the highest quality camshaft, we precision machine the camshaft lobes on Junker JUCAM machine. It runs two CBN (Cubic Boron Nitride) wheels, one at 450mm diameter and one at 80mm diameter with the capability to produce re-entrant lobe forms (think kidney bean shaped). It is hard wired into the Adcole form measuring machine so that we can run with a closed-cycle system. i.e. we grind a cam lobe nominally big then measure the form. This is then automatically corrected in the Adcole to allow for variances in geometry, temperature etc and then fed back into the Junker to produce a theoretically perfect cam form. We currently hold a form tolerance of around 0.004 to 0.006mm.

Junker JUCAM camshaft manufacturing

3.  Once the machining and grinding operations are completed, the camshafts are the inspected. We then complete the camshafts by applying a high polish superfinish to reduce friction and improve the surface finish of the camshaft.

 Finished Cosworth performance camshaft

Genuine Cosworth camshafts are available in a variety of race proven, engineered profiles designed to produce excellent engine response and power. When considering your next camshaft purchase, consider the Cosworth difference.