The result was the Cecy sleeve valve 2 stroke which never actually flew but the War Ministry engineers estimated it would have made 2,500 bhp from a smaller capacity and much less weight than the Merlin which at the time was doing about 1/2 that. Crecy used a 2 stroke engine design pioneered by Henry Ricardo. It was nothing like a bike engine with no expansion chambers or any sort of crankcase breathing like bike engines.

However, because the Merlin turned out so much better than expected (almost) all of RRs time and talent went into merlin development and the Crecy got ignored. It had fantastic potential but was eventually overtaken by the turbojet and never got off the testbed.

Apart from its brute power, the Crecy was also amazingly economical on fuel. It used direct injected petrol into a stratified charge combustion chamber. Rich mixture near the spark plugs but virtually pure air further down. The fuel pump was a modified diesel injection pump.

The Crecy had a normal sump like a 4 stroke with piston ports for the exhaust and a moving sleeve for inlet air. Its a shame they didnt appreciate that they did not actually need the sleeve valves. As long as the exhaust opens first the gasses will be gone by the time the inlet port opens, so both can be in the cylinder walls.

Direct injection, stratified charge, turbo and mechanical blower all done by Henry Ricardo in the 1930s.