Norton Technical Guides
Technical articles and restoration notes specifically relating to Norton motorcycles, including suspension, engine and chassis work.
My 1951 Norton ES2 was disappointing when it first went back on the road. This is how I developed the engine through changes to compression, carburation, valve timing, cams and ignition timing.
Making my Norton ES2 faster was only part of the job. I also worked on the suspension, brakes and other details to make it a more capable and enjoyable classic touring bike.
Over 15,000 miles of touring, I've gradually modified my 1951 Norton ES2 to make it more practical for longer trips without losing its classic character. Here's what I've changed and what I've learnt along the way.
The valve guides on my 1928 Norton CS1 wore out after only a few thousand miles. Rather than simply replace them, I investigated why and made a modification intended to protect the new guides from road dirt.
This guide looks at the piston options available when increasing the compression ratio of an OHV Norton engine. Standard ES2 pistons, modified 16H pistons, BSA B40 scrambles pistons and custom piston designs are compared, along with the advantages, drawbacks and machining work required to make each option work.
A Norton 16H piston can be modified for use in an OHV ES2 or Model 18 to increase the compression ratio. This guide covers shortening the skirt, checking deck height and machining the valve pockets.
This guide explains how to repair the damaged camshaft tunnel in a Norton SOHC cambox, a common issue on these engines.
A step-by-step guide to dismantling an Upright Norton gearbox, using a 1947 Model 18 gearbox as an example. Includes part numbers, gear cluster removal and advice on bearings and inspection.
This guide covers our preferred repair method, for repairing and fitting Norton gearboxes, including modifying the top mounting arrangement, repairing worn pivots and machining new mounting components to prevent the problem returning.
Engine data for Norton singles from 1928 to 1955 including bore, stroke, compression ratio and valve and ignition timing.
There are many ways to improve the performance of OHV Norton singles, possibly one of the simplest is optimising valve timing. On this page we will talk you through our recommendations for standard and alternative cams.
Post-war Nortons can be accurately identified and dated from the engine and frame numbers. This page will show you what you are looking for.
Pre-war Nortons can be tricky to identify using numbers alone. This page will give you some insight into what you are looking for.