A desaxe engine, is one in which each cylinder is positioned with its exact center (the bore axis) slightly offset from the center line of the

crankshaft A crankshaft is a mechanical component used in a piston engine to convert the reciprocating motion into rotational motion. The crankshaft is a rotating shaft containing one or more crankpins, that are driven by the pistons via the connecting ...

. "Désaxé", in French, means "unbalanced". Desaxe engines are usually automotive, but the term can also apply to

steam engine A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be trans ...

s. If the offset is in the direction of rotation, it has the effect of increasing the leverage applied to the crankshaft during the "power" stroke, and reducing thrust wasted against the cylinder wall. In a conventional four-stroke engine, each of the strokes (intake, compression, power, exhaust) involves a nominal rotation of 180°, totaling 720° for the complete 4-stroke combustion cycle. A desaxe engine adds to the duration of the two downward strokes (intake and power), and subtracts the same amount from the two upward strokes (compression and exhaust), with the total remaining 720°. A typical desaxe engine will have strokes of 185° - 175° - 185° - 175°, etc., with the differential roughly (but not directly) proportional to the percentage of offset distance to stroke length. The relative proportion of offset distance versus stroke length ranges from very small to almost 20%; viz. an engine with an 80 mm stroke may have a cylinder offset of 20 mm. Early adopters of the Desaxe Principle included Henry Ford who would fully implement the Desaxe offset into the

Ford Flathead V8 engine Ford commonly refers to: * Ford Motor Company, an automobile manufacturer founded by Henry Ford * Ford (crossing), a shallow crossing on a river Ford may also refer to: Ford Motor Company * Henry Ford, founder of the Ford Motor Company * Ford F ...

throughout the 1930s while adopting greater offsets into the 1940s. Use of desaxe engines is now becoming more common.. The Volkswagen VR6 & VR5 engines have desaxe cylinders, with an offset of 12.5 mm. The front bank cylinders are offset forward of the crank while the rear are offset rearward. The Toyota Prius has desaxe cylinder bores offset by 13 mm. The new MT-09 motorcycle is the first Yamaha with desaxe pistons. Ford has a new series of engines called dragon series that have an offset crank shaft. All single crank

split-single In internal combustion engines, a split-single design is a type of two-stroke where two cylinders share a single combustion chamber. The first production split-single engine was built in 1918 and the design was used on several motorcycles and ...

engines such as those used by

DKW DKW (''Dampf-Kraft-Wagen'', en, "steam-powered car", also ''Deutsche Kinder-Wagen'' en, "German children's car". ''Das-Kleine-Wunder'', en, "the little wonder" or ''Des-Knaben-Wunsch'', en, "the boy's wish"- from when the company built to ...

and Puch had, by necessity, highly desaxe cylinders. The Scuderi engine, as shown in the animated illustration, has highly desaxe cylinders. The compressor (blue) is offset a greater amount than the power cylinder (yellow). Its benefit is to give a better line of thrust from piston to crank though con-rod during downward power stroke but it has disadvantages in vibration and bore wall thrust.

References

* * {{ citation, url=https://www.autocarindia.com/auto-features/dragonheart-building-ford-ecosports-new-15-dragon-petrol-engine-406187, title=Building Ecosports new 1.5 dragon engine Engines