The Challenge
Polgain was approached by a diesel engine rebuilder working on engines for InterCity 125 trains. The project required the regrinding of two Paxman camshafts as part of a wider engine overhaul programme.
The camshafts presented handling and machining challenges due to their length and weight, which were significantly larger than those of typical camshaft work. Components of this size require careful setup and control throughout the grinding process to maintain accuracy and avoid distortion.
In addition, the camshafts formed part of engines destined for use in locomotives rebuilt at Crewe Works. As such, reliability and consistency were critical, with no margin for error in the finished profiles.
The Solution
Polgain applied its experience in large diesel camshaft work to carry out the regrinding process.
Each camshaft was assessed and prepared to ensure it was suitable for restoration, with attention given to maintaining the integrity of the base material and existing profile geometry.
Using precision grinding equipment and established processes, the cam profiles were restored to the required specification. The size and mass of the camshafts required controlled handling and accurate setup to ensure that profile accuracy, timing, and surface finish were maintained throughout.
By focusing on careful measurement, setup, and grinding, Polgain was able to successfully recondition both camshafts to a serviceable standard.
Damaged Inlet Cam (as received)
Ground Inlet Cam
The Outcome
The two Paxman camshafts were successfully reground and returned to the customer for reinstallation into the rebuilt engines.
By restoring the original components rather than replacing them, the project supported a cost-effective overhaul while maintaining the required performance standards. The engines were subsequently installed into locomotives rebuilt at Crewe, contributing to their continued operation.
This project demonstrates Polgain’s capability in handling large, specialist camshafts and delivering reliable regrinding solutions for demanding applications within the rail and heavy diesel sectors.
If you are working with large or specialist camshafts, facing machining limitations, or dealing with worn components that are difficult to replace, call us on 01502 532880 or email sales@polgain.com. One of our engineers will review your requirements and advise on the most suitable solution.
