The 1150-Hp Allison V-1710, a 12-cylinder, V-type, liquid-cooled engine, has a single-speed internal blower and integral reduction gears through which the propeller is driven. Models starting with the P-40 K have a manifold pressure regulator which automatically maintains constant manifold pressure up to 12,000 feet and eliminates the need for resetting the throttle with altitude changes. Above 12,000 feet the effectiveness of the regulator drops sharply. The Allison is a good, tough engine, but like all precision instruments it requires proper treatment. You, as pilot, are the controlling factor in how long the engine lasts, how well it operates. If you mistreat the engine, you can be sure of paying for your carelessness.

Watch your prop and throttle settings. excessive manifold pressure and rpm cause the engine to detonate. Detonation is an explosion in the cylinder head. The normal burning wave, as it travels across the cylinder head, subjects the unburned portion of the fuel charge to tremendous temperatures and pressures. If these forces are great enough, the remaining fuel charge explodes before it can burn, and the shock waves from. this explosion rob your engine of power. If the waves are strong enough, they can blow the cylinder heads off the engine. As long as you remain within the normal operating limits of the engine, you run no risk of detonation.