The dilemma of the present four stroke internal combustion engine• High efficiency requires high expansion ratio.• High power density requires low compression ratio.

but impossibly

expansion ratio = compression ratio

To cut the knot we prefer an engine

• High efficiency requires still high expansion ratio.• High power density requires still low compression ratio.

and possibly

expansion ratio ≠ compression ratio.

How can it be possible to turn impossible to possible?

Let’s change the things• Why not add an additional degree of freedom?• Why not concentrate the different cylinders on different tasks?• Why not add an additional stroke to the engine and increase its

efficiency?

there is no reason not to try it

Requirements of this engine• The building of new engine is a cast cylinder head, a machined solid

cylinder block and separate electrically powered oil and water pumps.• Two overhead camshafts operate conventional coil spring valve with cam

shafts for four stroke cylinders running at one half crank shaft speed and the fifth stroke’s cylinder camshaft running at crankshaft speed.

• The engine also turbocharged to increase the engine speed.• The engine runs an overall expansion ratio in the region of 14.5:1.

A new engine is born• Second and third Cylinders(C2,C3) are working on the four stroke cycle

mode and the first cylinder(C1) acting on two stroke cycle mode. • The exhaust gases make the first cylinder to make the expansion stroke.• For this we requires an low compression cylinder as the first cylinder.

let’s the working process of this cylinder.

Working process of this engine

Software design- stage 1 engine

Hardware manufacturing- stage 1 engine

Software design of stage 2 engine

5- stroke engine performance figures

• Engine capacity 700cc(turbocharged).• Peak power 130 bhp@7000rpm.• Peak torque 166 Nm @ 5000rpm.• Fuel consumption of only 226 g/Kw h.

Advantages of 5-stroke engine• A secondary cylinder provides an additional expansion process enabling

extra work to be extracted.• The expansion ration is of 14.5:1 approaching up to diesel engine.• Minimized pumping work.• The compression ratio can be reduced to delay knock onset without

reduction in performance.• The fuel consumption does not rise as suddenly with increasing in BMEP,

as retarding rejects more energy in the expansion cylinder.• The engine uses 100% conventional technology. • Producing more thermal efficiency than four stroke engine.

Disadvantages of 5- stroke engine

• 5% costlier than the current 4-stroke engine.• The entire construction requires current manufacturing technology.

Further improvement in this engine

• Brake specific fuel consumption of 215 g/Kw h.• 20% lighter than the existing production engines.• Power density of 150 bhp/L

It is a simply an ingenious efficiency engine with less fuel emissions than current engines.

Presented by

G. Jaya krishna sekhar reddy