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Crankshaft Grinding and Polishing

South Cerney Engineering offers crankshaft grinding and polishing on pretty much anything. 

We have reground and polished crankshafts for many decades, rectifying problems with bearing shells and to suit white metalling.  Based between Cirencester, Gloucestershire and Swindon Wiltshire we are centrally located and easy to get to for crankshaft grinding and polishing services.

Crankshaft grinding is a repair process used for grinding back the damaged surface of a crankshaft journal back to fresh material. This in turn will make the crankshaft journal smaller so a thicker bearing shell will need to be purchased to accommodate the material removed from the journal. 


Crankshaft big end journal showing heavy marking/scoring

When to regrind a crankshaft

Crankshaft grinding is undertaken at the point when an engine is being rebuilt. Upon measuring and inspecting the condition of the bearing journals will determine as to whether the crankshaft is suitable for a regrind or requires only a polish before going back into service. Crankshaft grinding isn’t automatic at rebuilds, if the crankshaft is within the manufacturers limits on standard bearing shell size and hasn’t suffered scoring, then it is most likely a polish will be suffice. 


A selection of crankshafts we have reground and polished

Race cars, saloon cars, single seaters, F5000.
Classic and vintage cars, Aston Martin, Jaguar, Bentley, Ferrari, MG, Ford, Vauxhall and many more
Various steam engines, traction engines.
Tractors, such as Ford 7810, New Holland T8, Massey Ferguson 6170, John Deere, Marshall, Case International,
Light aircraft aero engines
Motorcycle crankshafts for Triumph, BSA, Norton

Based between Cirencester, Gloucestershire and Swindon Wiltshire we are centrally located to offer crankshaft grinding and camshaft polishing to a wide range of industries. 


Crankshaft Polishing

A polished crankshaft journal if properly lubricated will run very smoothly, minimising heat, fatigue and therefore wear on the bearing shells and journal. Crankshaft polishing is also useful where a crankshaft is within manufacturers tolerance limits but the surface isn’t great. A polish will shine up the journal extending the crankshaft service life before needing to be reground.  Crankshaft polishing is usually done on a lathe at low speed with a lubricant and a polishing machine in the correct direction for best results. Journals which are highly loaded such as diesels or high performance or race engines really benefit from a polished surface

Camshaft Polishing

We sometimes polish camshafts, this a process done initially by hand on a lathe before finishing off with a polishing machine. The purpose of polishing a camshaft is to extend the service life of the camshaft by making the lobe surfaces smooth to run on the tappets.  The tappets should be checked as well to make sure the surface is smooth as well.

Jaguar E type lip seal conversion, scroll removal

Some classic and vintage engine crankshafts require modifying, one such crankshaft is the Jaguar E type, to perform the lip seal conversion the original scroll needs to be machined off then the surface needs to be polished up for the seal to have an excellent long service life.  We also offer to remove crankshaft bungs, a very difficult task to do without the correct tools.


Before and after shots of the scroll being machined off a Jaguar E type crankshaft for the lip seal conversion

Get in touch

Our friendly team of time served engineers can advise on the most suitable methods to be used to clean your parts.

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