DESCRIPTION & OPERATION
Page 55
GLOSSARY OF TERMS
Breather Canister
A canister through which blow-by gases are
filtered to remove engine oil for return of oil to the
crankcase. The canister is mounted on the
engine front cover.
Breather Filter
A meshed metal filtration element inside the
breather canister. The element can be removed,
cleaned and reinstalled in the canister.
Electronic Unit Pump (EUP)
An electronically controlled fuel injection pump,
one for each cylinder of an engine. The electronic
unit pumps are actuated by roller followers and
lobes on the engine camshaft.
Engine Electronic Control Unit (EECU)
A microprocessor-based controller, sometimes
referred to as a module, mounted on the right or
left side of the E-Tech™ engine. With the MACK
V-MAC III system, the EECU primarily controls
fuel timing and delivery, fan operation, engine
protection functions and engine brake operation.
H-Ring
A type of guide ring used to prevent axial rotation
of the valve roller follower. On the E-Tech™
engine, a ring is press-fit into each valve lifter
bore.
Idler Gear
A timing gear positioned between the crankshaft
and camshaft gears in the front gear train of the
E-Tech™ engine.
Idler Tensioner
An automatic belt tensioning device designed to
maintain optimum tension under varying engine
speeds and load. The idler tensioner is optional
on the E-Tech™ engine.
Poly-V Belt
A multi-ribbed belt design which is incorporated
into a single drive belt and pulley system at the
front of the E-Tech™ engine.
Pump Line Nozzles (PLN)
A fuel injection system using a single multi-
plunger fuel injection pump supplying fuel to
individual nozzles at each cylinder. (This system
applies to the E7 engine only and not the
E-Tech™.)
Roller Follower
A type of lifter with an axle-mounted roller that
rides on (or follows) a camshaft lobe. The rolling
motion of this design provides increased load
capacity with less friction than the flat-faced lifter
design. Roller followers are used to provide the
lifting action for the electronic unit pumps and the
intake and exhaust valves on the E-Tech™
engine.
Tappet Guide Pin
A pin used to prevent axial rotation of an EUP
tappet. The pin is pressed into the cylinder block
EUP tappet bore wall and fits into a slot in the
tappet.
Vehicle Control Unit (VECU)
A microprocessor-based controller, sometimes
referred to as a module, mounted in the cab,
inside the passenger-side dash panel. With the
MACK V-MAC III system, the VECU controls
engine speed, cruise control, accessory relay
controls, idle shutdown, and trip recorder
functions.
5_106_00.bk Page 55 Friday, August 4, 2000 11:17 AM
BDC for engine manuals and specs
