Petter AC1WM - "Mini-Six"
Single cylinder, 6hp direct injected diesel. Original fit in Westerly 21 (others?). Alloy crankcase and head, cast iron cylinder block. Raw water cooled. Gearbox: 2:1 (forward and reverse). Anti-clockwise (when looking fwd) Left handed propeller.
Most wearing parts are still available from Lister-Petter's distributors, including bearings, rings, oil seals and gasket sets. Cylinder heads and exhaust manifold are no longer available (in 2010). Gearbox bearings are standard sizes available from any bearing supplier.
Petter Marine Diesels 'Mini-Six' AC1WM Instruction Book, Issue 2, Publication No 340971, Petters Limited.
Petter Diesel Engines AB1W-AC1W Operators Handbook, Issue 2, Publication No 340937, Petters Limited.