I’m pleased to say that we now have the recently manufactured high-quality, lightweight forged 7.5:1 pistons available on the Sunbeamland Shop in +0.020″ and +0.040″ oversizes.  Modern materials and CNC machining mean that all-up weight is within a few grammes of the original Marston’s item and I’m enjoying the experience of running one in on my own 1930 Model 90. They should fit any of the late 20’s early 30’s 500cc OHV bikes and we hope to be following up with production of a small batch of 6.5:1 pistons aimed more at the Model 9.

Forged piston for Sunbeam Model 9 and Model 90 7.5:1 compression ratio