Piston Engine Propulsion

Types and arrangements

Piston Engine Types - Layouts

Single Inline 3

Vee

Twin

Inline 4

Inline 5

Vee 5 Vee 6 Vee 8

Piston Engine Types - Layouts

Piston Engine Types - Layouts

Firing Order: -

1 – 4 – 3 – 2

Horizontally Opposed (Or flat) 4 Vee 8

1 – 8 – 4 – 3 – 6 – 5 – 7 – 2

Piston Engine Types – 2 Stroke Cycle

Port A –

Crankcase

Inlet

Port C -

ExhaustPort B –

Cylinder

InletPiston rising pulls

fuel/air mixture into

crankcase;

compression

causes combustion

Piston pushed

down forces

fuel/air mixture

into cylinderPiston at BDC

Stroke 2

Piston at TDC

Stroke 1

Mechanical Arrangement – Petrol

Engine Cross

Section

Same mechanical set-up

as petrol engine

Inlet Exhaust

But no spark plugs!

Direct

Injection

Indirect

Injection

Diesel

Combustion initiated by

hot compressed air

Mechanical Arrangement – Wankel Engine

Inlet

Port

Exhaust

Port

Casing

Spark

Plug

Output

Shaft

Rotating

Triangular

‘Piston’

Fixed (non-

rotating)

Pinion

This motion drives the rotating

crankshaft

Which in turn drives the output shaft

The piston rotates around the fixed pinion

But the shape of the piston and

the casing also make the

piston move up and down by a

small amount as well

Rotating

‘Crankshaft’

Engine Cross Section

Points of contact

marked in yellow

Chamber A

Engine Cycle

Chamber C

Inlet

Port

Exhaust

Port

Chamber B

Mechanical Arrangement – Wankel Engine

Mechanical Arrangement – Radial/Rotary Engines

Cylinders

Crankcase

Valve

Gear

Valve

Pushrod

Spark

Plug

Propeller

Mount

Bolts

Radial powered motorbike

Mechanical Arrangement – Radial/Rotary Engines

Radial

(viewed from the side)

Rotary

(viewed from the side)

28 Cylinder Radial

Model

aero

engine

Aircraft

Nose

Aircraft

Nose

RHONE

(viewed from the front)

Radial/Rotary

Flat Twin

Hand

Held

Is there any limits to size?

They go from tiny: -

Mechanical Arrangement – Engine Size

Cylinder

Liners

Cylinder

Block

Cylinder

Head

Bolts

Flywheel

Crankshaft