Flexible fuel vehicles can operate on a mixture of
up to 85 percent methanol, 15 percent unleaded gas-
oline. These vehicles also operate on mixtures con-
taining a lower percentage of methanol or just pure
unleaded gasoline.
Engine components which are required for safe op-
eration using fuel containing methanol alcohol are
identified by a standard green color and/or display
the statement methanol compatible imprinted on the
component. To ensure continued safe operation, these
components must be serviced only with genuine MO-
PAR replacement parts.
Methanol compatible parts for the 2.5L FFV (Flex-
ible Fuel Vehicle) engine include, but are not limited
to; the valve stem oil seals, all piston rings, the oil
fill cap, the fuel injectors, fuel rail, fuel pressure reg-
ulator, hoses and the vacuum control harness hose.
BLOCK: All four cylinder cast iron blocks have
cast-in recesses in the bottom of each cylinder bore to
provide connecting rod clearance; especially needed
for 2.5L engines. The bores are also siamese to min-
imize engine length. A coolant passage is drilled
cross-ways through the siamese section to enhance
between the bore cooling on some engine types. A
partial open deck is used for cooling and weight re-
duction with oil filter, water pump, and distributor
mounting bosses molded into the front (radiator side)
of the block. Nominal wall thickness is 4.5 mm. Five
main bearing bulkheads and a block skirt extending
3 mm below the crankshaft center line add to the
blocks high rigidity with light weight.
CRANKSHAFT: A nodular cast iron crankshaft is
used in TBI engines. A forged steel crankshaft is
used in the Turbo III engine. All engines have 5
main bearings, with number 3 flanged to control
thrust. The 60 mm diameter main and 50 mm diam-
eter crank pin journals (all) have undercut radiuses
fillets that are deep rolled for added strength. To op-
timize bearing loading 4 counterweights are used.
Hydrodynamic seals (installed in diecast aluminum
retainers) provide end sealing, where the crankshaft
exits the block. Anaerobic gasket material is used for
retainer-to-block sealing. No vibration damper is
used. A sintered iron (TBI engine and steel billet
Turbo III engines) timing belt sprocket is mounted
on the crankshaft nose. This sprocket provides mo-
tive power; via timing belt to the camshaft and inter-
mediate shaft sprockets (also sintered iron (TBI
engine and steel billet Turbo III engines) providing
timed valve, distributor, and oil pump actuation.
PISTONS: Some Chrysler pistons have cast-in
steel struts at the pin bosses for autothermic control.
All 2.2L and 2.5L piston tops have cuts to provide
valve clearance. Some pistons are dished to provide
various compression ratios. Standard 2.2L and 2.5L
engines are designed for 9.5:1 and 8.9:1 compression
ratios respectively. The 2.5L piston is dished and is a
lightweight design to enhance engine smoothness.
The 2.2L turbo III uses dished pistons providing a
8.3:1 compression ratio. All standard 2.2/2.5L and
2.5L FFV engines use pressed-in piston pins to at-
tach forged steel connecting rods, 2.2L turbo III en-
gine uses a full floating piston pin and connecting
rod assembly.
PISTONS RINGS: The 2.2/2.5L engines share
common piston rings throughout, including molybde-
num filled top ring for reliable compression sealing
and a tapered faced intermediate ring for additional
cylinder pressure control. The 2.5L FFV engine fea-
ture all chrome rings for enhanced long term dura-
bility under multi-fueled conditions.
CYLINDER HEAD: The cylinder head is cast alu-
minum with in-line valves. The 2.2/2.5L and 2.5L
FFV valves are arranged with alternating exhaust
and intake. The intake and exhaust ports are located
in the rearward, facing side of the head. The Turbo
III valves are arranged in two inline banks, with the
ports of the bank of two intake valves per cylinder
facing toward the radiator side of engine and ports of
the bank of two exhaust valve per cylinder facing to-
ward the dash panel. The intake ports feed fast-burn
design combustion chambers (2.2/2.5L and 2.5L FFV
only) with the spark plug located close to the center
line of the combustion chamber for optimum effi-
ciency. An integral oil gallery within the cylinder
head supplies oil to the hydraulic lash adjusters,
camshaft, and valve mechanisms.
CAMSHAFT: The nodular iron camshaft has five
bearing journals (2.2/2.5L and 2.5L FFV). The Turbo
III employs dual camshafts that have nine bearing
journals. Flanges at the rear journal control cam-
Fig. 1 Engine Identification
Ä
2.2/2.5L ENGINE
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