Plated Cylinders

Pros

Cheaper to manufacture (initially)

Lighter by about 150gm (125cc cylinder).

The plated surface is very hard and suffers almost no wear.

However the aluminium behind it is soft and “packs back” over time, resulting in an increased piston clearance, even without bore wear. This cannot properly be rectified with a larger grade of piston since the wear is not uniform and a larger grade piston will be at risk of seizure.

Can potentially run very small piston to bore clearance to give a performance advantage.

Very few engine builders, or indeed manufacturers are prepared to run so close to the edge for their customers. Almost all choose to run clearances in the order of 0.040mm, exactly the same as a linered cylinder! – Forged pistons often need even larger clearances!!

Cons

Expensive and very time consuming to re-condition – cannot be rebored.

Cannot easily be honed to remove small imperfections or damage so that even the smallest fault cannot safely be rectified.

Running an imperfect cylinder risks plating detachment and total failure with potential catastrophic collateral damage to the rest of the engine.

Linered cylinders.

Pros

Mitaka offer an economical relining service.

The initial wear can be easily corrected by honing and a larger grade piston fitted to restore the exact specification.

Extended wear or serious damage can be economically repaired by reboring.

Cons

Heavier (150gm)

Can’t think of anything else, unless you can afford a new cylinder for every race.

WHICH IS THE BEST SOLUTION FOR YOU ?