SIEs
Spark Ignition Engines
CIEs
Compression Ignition Engines
TDC
Top Dead Centre
HEDC
Head End Dead Center
TC
Top Center
bTDC
Before Top Dead Centre
aTDC
After Top Dead Centre
BDC
Bottom Dead Center
CEDC
Crank End Dead Center
BC
Bottom Center
DI
Direct Injection
IDI
Indirect Injection
EMS
Engine Management System
WOT
Wide Open Throttle
ID
Ignition Delay
AF
Air Fuel Ratio
FA
Fuel Air Ratio
BMT
Brake Maximum Torque
ORV
Overhead Valve
ORC
Overhead Cam
FI
Fuel Injected