Chrysler - Plymouth - Dodge 2.2 and 2.5 liter engines - chronology
This was the first year for the 2.2 liter engines, built at Trenton Engine, where big-block V8s had once rolled down the line. The 2.2 produced 84 horsepower @ 4800 rpm and 111 ft-lbs of torque @ 2800 rpm. Midyear, the underhead flat was removed from the intake valve.
The engines used a cast iron block with aluminum pistons and an aluminum cylinder head; fuel was delivered by a two-barrel Holley electronic feedback carburetor, with an antifreeze-heated intake manifold. The aluminum intake manifold had long, completely separate runners for each cylinder. The new engine was used in a wide variety of cars starting in 1981.
A slightly different intake manifold with shorter, integrated runners and a larger plenum was used; it still produced 84 horsepower; MasterTech News claimed the aluminum manifold provided “a significant improvement in top end horsepower.” Exhaust and intake valves were modified for better airflow. The cam centerline was changed to improve torque; a minor change in the cam sprocket keyway allowed for relocking the cam from 110° to 106° (advancing the cam increased torque without lowering horsepower). TRW exhaust valve seats were used; a new "D" intake manifold was launched as a running change. Stock was added to the block between the cup plugs, below the manifolds. Teacup oil filter.
|1983||The first year for the A511 "G" casting cylinder head, with slightly more airflow then the older head. Using .030" higher pistons for an increased compression ratio give the engine 94 hp, more than it would have with throttle-body injection. A new exhaust manifold was used, flanges were removed from sprockets (running change), low load valve (135 lb; white) springs were substituted, and an anti-drainback valve was added.
The Shelby Charger used a modified engine pushing out 107 hp, roughly a 10% increase. Differences were slightly richer carb jets, a .030" milled engine block (raising compression to 9.6:1), increased piston fit clearance, 4°-advanced cam phasing, detonation sensor, chrome-plated valve cover, and a slightly different engine computer. The engine was introduced midyear, and reportedly was developed internally with Carroll Shelby providing general guidance.
The A465 five-speed manual replaced the A460 four-speed in most cars (the A465 added an overdrive gear, and had an extended case cover to make room).
Changes included hardened powdered-metal inserts on top of each rocker arm (where the cam lobe contacted it), reducing friction with the cam, extending the lives of both parts; the valve spring pressure was also reduced. The carbureted 2.2 liter engine was up to 96 hp @ 5200 rpm.
The Shelby engine was carried over from mid-1983, and used in the Omni GLH; horsepower was now rated at 110 hp @ 5,600 rpm with torque at 129 lb-ft @ 3,600 rpm (changes are unknown). It was only available with a five-speed manual, with overall top gear ratio of 2.57:1.
The TBI (throttle body injection) system was launched, pushing the 2.2 to 99hp @ 5600 rpm, with 121 lb-ft of torque. The Daytona/Laser launched with the TBI 2.2 and the New Yorker was upgraded to one, but the popular, less expensive Reliant/Aries/Lebaron had to wait; they still used a carburetor.
Head bolts were upgraded from 10mm to 11mm, and the A-525 manual transmission debuted on the Daytona and Laser.
Related changes included a 90 amp Bosch alternator with internal voltage regulator on EFI cars and any fleet vehicles (the voltage regulator was part of the brush holder, mounted on the rear housing); a new aluminum radiator was used with non-air conditioned L-bodies, cutting four pounds and increasing reliability; K, E, and G cars with the 2.2 got new copper/brass radiators, one pound lighter and more durable. Transmission oil coolers could be external or internal, depending on the car. The thermostat was given a better seal when closed. Timing belt flanges were removed, to make cover removal easier, and the PCV system was changed to ease maintenance. The snorkel and retaining clip were also altered for maintenance.
Other changes include higher load valve springs (both normal and turbocharged engines), stamped rockers with P/M inserts, a lightweight crankshaft, oil pump relief raised from 60 to 70 psi, a turbo oil drain boss added to the block, and removed lubrite from the camshaft.
Chrysler sold the Shelby engine as an option in any Charger or Turismo with a 5 speed manual transmission.
The new 287 head replaced the 455 heads on carbureted engines; it was similar but had a new a/c compressor mount. There was a new seal ring gasket (exhaust donut).
Other changes included the A590 (solid mount a/c) bosses on block and head, oil management block (running change), improved intake valve surface, lightweight connecting rod (running change), high temp timing belt, 11 mm head bolts (running change), integral water box on bottom of intake manifold, better anti-drainback valve (running change), oil pump relief back down to 60 psi, 8 bolt flywheel (late change), material added to head and block at oil transfer hole, .94 rotor oil pump (late change)
The first year for the A515 "fast burn" cylinder head and notched "fast burn" pistons, designed to decrease emissions; power output was the same for all but the TBI, which dropped slightly to 97 horsepower.
The 2.5 liter engine was launched; it used the same cylinder head as the 2.2, with standard single point throttle body injection, a taller block, and balance shafts in the oil pan (because there was no other place to put them).
A new throttle body design for the TBI injection system had a low profile and concentric direct mount for the air cleaner, improving fuel-air distribution. A fuel temperature sensor was compensate for fuel density changes. The automatic idle system got a new actuator, using a stepper motor to position a conical pintle valve in an air passage, giving more precise control than the prior DC motor and circulate segment; it included a speed compensator for the air conditioning compressor. The control logic counted and measured the steps taken.
For 1986, a new “labyrinth” distributor was smaller, had fewer parts, and easy to service; and it was designed with fuel injection synchronization in mind, via both Hall Effect and turbo-sync connectors.
Other changes: low tension ring package, heater bypass moved to water pump, thicker head gasket (running change), new valve cover with curtain to prevent oil splashing, new 175# valve spring on all engines, 2 mm longer valves (both intake and exhaust), exhaust guide materials changed to a medium phosphorus iron, rocker pad surface finish improved, cam plug instead of lip seal in rear, better rod caps, crank drilled for N body (rear wheel drive), common dipstick and tube.
A modified longitudinal-mount 2.2 is used in the Dakota pickup - carbureted; and the A520 five speed manual comes out.
All Chrysler four-cylinder engines now had fuel injection. The 2.2 TBI dropped to 93 hp, with no explanation; it would stay at this level until the end. Rocker camshafts were adopted in all 2.2 and 2.5 engines, improving idle quality, gas mileage, and longevity by cutting friction between the cam and hardened inserts on their followers; post-hardening of the nodular iron camshaft was believed to be an industry first. The new system cut friction by 20%, raising city gas mileage by 4% (automatics) or 3% (manuals).
The computer modules were combined into a single-module engine controller (SMEC) with two circuit boards; the CPU was upgraded and programming was refined, allowing for the engine to cancel limp-in mode.
2.2 turbo engines used a milder cam for smoother idles, cutting valve overlap time by 30%.
A new common block was used for turbo, standard, and 2.5 liter engines; it included stronger main bearing supports and caps, thick cylinder walls, balance shafts (only used on the 2.5 and late turbo 2.2) and cross drilling between the cylinders. Without a lengthened deck, the 2.5 liter engine maintained its displacement with a shortened piston.
Non-turbo engines got a new injector and higher fuel pressure.
The CPU on the SMEC was upgraded again.
“Phase II Quiet Idle,” began, including an acoustic cylinder-head cover (already used on turbos), a change to the tooth style on cam belts (deep rounded teeth), plugs for the timing indicator and probe in 2.5 Turbo I and manual-transmission cars, and a transmission dust cover-to-engine oil pan foam seal on 2.5 Turbo I and manual-transmission cars. Idle quality was improved by cutting valve overlap by 30% (this had already been used on 2.2 Turbo I and II engines in 1988).
A single board computer replaced the dual-board unit. An acoustical stamped steel valve cover, with a single-piece gasket, cut noise and, in theory, leaks; powered metal intake and exhaust guides improved lubrication; increased piston wrist pin bore surface area increased connecting rod-to-wrist pin support; 2.5 engines had increased wrist pin stiffness; and a new water pump impeller shaft seal and bearings were used.
|1991||The Turbo III appeared with a Lotus-designed dual-cam head (Turbo III). The Turbo III produced an amazing 225 hp from 2.2 liters - propelling the five-passenger Spirit R/T sedan from 0 to 60 mph in under six seconds without modification. It was used in just two cars in the US, the Spirit R/T and Daytona R/T (in Mexico, the LeBaron R/T also used it).|
The 2.5 turbo had an increased torque peak, due to improved fuel and ignition timing control and more low-speed boost; no hardware changes were made, and horsepower was unchanged.
The export-only 2.5 liter MPI engine produced with 106 hp; an American version was used in flex-fuel engines that ran on ethanol.
The Neon started production late in the year with a 2.0 liter engine, destined to replace the 2.2. It had some of the same dimensions as the 2.2 to reduce tooling costs, but pumped out 132 hp and 129 lb-ft of torque. A dual cam version was rated at 150 hp.
For unexplained reasons, the 2.5 MPI dropped to 103 hp and the 2.2 dropped to 92 hp in their final year. In either 1993 or 1994, a cast valve cover was used with a one-piece gasket that did not require RTV and finally solved the valve cover gasket leakage problem.
The 2.2 and 2.5 have finally left production; minivans switch to a stroked Neon engine, rated at 150 hp, while the Dodge Dakota switched to the venerable 2.5 liter AMC engine producing 125 hp (25 hp more than the 2.5, with similar torque to the 2.5).
From shelbycsx.com: “Chrysler licensed First Auto Works (FAW) of Changchun, People's Republic of China, to build the 2.2L for the Chinese market. FAW began production in 1990, and the engine was still in production there as of July 2000.”
The end of the 2.0 and 2.4 engines is announced, replaced by a “World Engine” initially designed by Hyundai, and substantially redesigned by both Chrysler and Mitsubishi.
|2010||The last PT Cruiser is built, and the 2.4 liter four-cylinder engine is dropped. The last traces of the 2.2 design disappear with it.|
Key 2.2 - 2.5 engine links
- Mopar 2.5 / 2.2 Turbo Engines Performance and Common Repairs
- Interview with engine designer Pete Hagenbuch , which covers the 2.2 turbos and other topics.
- Interview with engine designer Willem Weertman
- Main info pages: 2.2 and 2.5 engines without turbochargers • turbocharged 2.2 and 2.5 engines
- Turbo bleeds (to increase boost)
- Turbo boost spiking and boost creep
- Sensors and computer fault codes: what they all do, what they all mean
- 2.2/2.5 liter repairs page
- Interview with a Garrett turbocharger engineer (at acarplace.com)