Wolfmet Tungsten used to Restore Racing Engine

When the Wolfmet team at M&I Materials were approached by Straight and Level Aircraft Engineering Services to help them restore a unique F3 racing engine, their vast experience within the motorsport industry allowed them to provide a bespoke solution to a very specific problem.

Archie Butterworth, a charismatic engineer and racing car driver, was responsible for developing a number of innovative racing engines during the 50’s. Just as the design was perfected in 1958, his friend and team driver Arthur Scott Brown was killed racing a Lister Jaguar, and Archie closed his workshop to work on other projects.

After Archie’s death in 2005, his great nephew Miles McCallum, an ex-motorcycle racer and aircraft restorer, decided to fit the single cylinder swingvalve engine into a contemporary motorcycle chassis. He manufactured the necessary parts and set about the task of getting it running again.


Amongst some of the many challenges facing Miles was excessive vibration, meaning a change to the crankshaft balance factor would be required. This was due to the engine being mounted in an upright position rather than the original horizontal configuration.

After a painstaking CAD modelling and investigation process it was decided that Wolfmet tungsten alloy would be perfect to create the counterbalance weights needed for the crankshaft, as it could easily be machined to the required size. Its high density also meant it could be fitted into a smaller space and still meet the necessary specification.

Miles McCallum of Straight and Level Aircraft Engineering Services, commented: “It’s been a hugely challenging project and what looked like an arduous and protracted task proved to be quite straightforward with the help of M&I Materials. The desired balance factor is a function of both the engine and the chassis installation, and can only be found by experiment. Incorporating Wolfmet counterbalance weights allows me to zero in on the optimum setting with precision and ease.”

Tests have shown a positive reduction in vibration as Miles continues to develop the work started by his great uncle decades earlier.