The Merlin 66 generated 2050 horsepower, almost entirely as a result of improved fuel supply and supercharging. The Spitfire was recovered and put back into service but when the site was investigated many years later, pieces of the engine were found in the soil. Another view of Merlin III no. 13751. The shaft onto which the propeller was fitted is on the left, still wearing its factory protective covering. The bulge on the back of the engine is the supercharger.
Aircraft reach high altitudes where the air is thin.
Just like us they can't breathe properly. The vertical row of closely-spaced horizontal bolts towards the lefthand end of the engine seals the passage through which the pressurised fuel mixture is sent to the engine. The supercharger bulge is clearly visible at centre right. Here's what remains of a Merlin 66 engine which comes from Mosquito PR.IX LR412 of 540 Squadron. It crashed on 9 February 1944 at Aran Fawddwy near Bala in Wales.