Allpar Forums banner

Chrysler - Plymouth - Dodge 2.2 and 2.5 liter engines - chronology

14106 Views 0 Replies 1 Participant Last post by Content
Chrysler - Plymouth - Dodge 2.2 and 2.5 liter engines - chronology

based on work by Aaron Karpinski; expanded by the Allpar staff over time

Engine Auto part Vehicle Car Automotive engine part

Turbocharged engines split out in the boxed sections. Also see our main sections on the 2.2 / 2.5 TBI and turbocharged 2.2 and 2.5 liter engines.


The first 2.2 liter engines were 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.

Cast iron blocks were topped with aluminum cylinder heads; fuel was delivered by a two-barrel Holley electronic feedback carburetor, with an antifreeze-heated aluminum intake manifold bearing long, separate runners for each cylinder. Though brand new, the 2.2 was used in a wide variety of cars.

The first known turbocharged 2.2 liter engine was built for use in the PPG pace car.


The company changed the intake manifold (as a running change) to use shorter, integrated runners with a larger plenum, without changing the power rating. MasterTech News claimed the aluminum manifold provided "a significant improvement in top end horsepower." Exhaust and intake valves were also 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). Stock was added to the block between the cup plugs, below the manifolds; and they switched to the "teacup" oil filter.

A turbocharged 2.2 was put into a Plymouth Reliant for testing; the combination never reached the public.

1983The first year for the A511 "G" casting cylinder head, with slightly more airflow. Using .030" higher pistons to increase the compression ratio give the engine 94 hp. They used a new exhaust manifold, removed flanges from sprockets as running change, substituted low load valve springs (135 lb; white), and added an anti-drainback valve to prevent oil issues.

The Shelby Charger pushed out 107 hp, roughly a 10% increase. To get there, Chrysler engineers used slightly richer carb jets, a .030" milled engine block (raising compression to 9.6:1), increased piston fit clearance, 4°-advanced cam phasing, a detonation sensor to prevent knocking with the higher compression, and a slightly different engine computer. The engine was introduced midyear, separated from others by chrome-plated valve cover.

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).


Hardened powdered-metal inserts were added to the 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 used in the Omni GLH; horsepower was now rated at 110 hp @ 5,600 rpm with torque at 129 lb-ft @ 3,600 rpm. 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, cutting emissions, increasing mileage, and improving driveability; it pushed the 2.2 to 99hp @ 5600 rpm, with 121 lb-ft of torque. The TBI units were limited to the new Daytona/Laser and the New Yorker; the popular Reliant/Aries/Lebaron still used a carburetor.

Head bolts were upgraded from 10mm to 11mm, and the A-525 manual transmission debuted on the Daytona and Laser.

The company started using a 90 amp Bosch alternator with internal voltage regulator on EFI and fleet cars, and switched to a new aluminum radiator on non-air conditioned L-bodies, cutting four pounds. K, E, and G cars with the 2.2 got new copper/brass radiators, one pound lighter and more durable. The thermostat was given a better seal when closed. Timing belt flanges were removed, to make cover removal easier, and the PCV system, snorkel, and retaining clip were changed to ease 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.

The first official turbocharged 2.2 was produced - the Turbo I engine, which pumped out a V6-beating 142 hp in the Dodge Daytona (and only the Daytona, this user). It used multi-point fuel injection, a turbocharger with the wastegate set to limit boost to 7psi (via pneumatic control), and a compression ratio lowered to 8.5:1 to reduce detonation. Other changes include hardened inserts added to rockers, higher load valve springs (both NA and turbo), bigger rods, stamped rockers, lightweight crankshaft, oil pump relief raised to 70 psi. The fuel injection system was engineered and built at Chrysler's Huntsville plant; it was hooked up to the 525 manual transmission or an automatic.

This was the second American front wheel drive vehicle with a turbocharger, after the 1979 Buick Riviera.


Chrysler sold the "Shelby" engine as an option in any Charger or Turismo with a five-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)

Computer-controlled boost (based on eight conditions) allowed for more precise control and a "transient boost system" allowing short runs at 9 psi; detonation control was improved. Horsepower rose slightly, to 146. The turbo's maximum safe temperature was 1650° F.

Other changes were the same as on the standard engines. At this point Chrysler was using the AiResearch TO3 turbocharger with an integral wastegate.

A 16 valve DOHC version of the turbo was used in a 4x4 Daytona project. Slated for production but cancelled, they would have run on regular fuel, with a Hans Herman head, custom manifolds, Garret 10 psi turbo, and the 225 horses seen in the 1991 Spirit R/T. Shelby versions produced 340 horsepower with 20 psi of boost and other modifications.


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 the turbos and carbs, but the TBI 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 TBI throttle body had a low profile and concentric direct mount for the air cleaner, improving fuel-air distribution. A fuel temperature sensor was used to figure out 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; 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.

The logic module controlled timing, emissions controls, idle speed, air/fuel ratio, and wastegate activation; the power module converted the logic module's output to alter the length of injector pulses and control timing.

The first year for the A515 "fast burn" cylinder head and notched "fast burn" pistons, designed to decrease emissions. The Shelby Omni GLH-S was offered with a prototype Turbo II intercooled 174hp engine with a 12psi boost limit, that would, with some changes, be a factory production engine later on. The turbo engines got new pistons to make up for changes in the heads, so they would maintain their compression ratio; and
lighter forged rods that reduced reciprocating mass.

Text Diagram Technical drawing Auto part Parallel

A modified longitudinal-mount 2.2 was used in the Dakota pickup - carbureted; and the A520 five speed manual came out.

The Shelby CSX and the factory Turbo II debuted. The Turbo II was similar to the Shelby intercooled turbocharger, but with added durability; it used a stronger crankshaft, rods (from the 1984-85 Turbo I), and Mahle pistons, with larger injectors and new programming. Shelby continued to use its version, without a strengthened bottom end, and with a two-piece intake manifold.


Chrysler dropped the carburetors at the end of the 1987 model year. The 2.2 TBI dropped to 93 hp, with no explanation. Rocker camshafts were adopted in all 2.2 and 2.5 engines, improving idle quality 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.

Auto part Camshaft Automotive engine part Transmission part Hardware accessory

A smaller, lighter Mitsubishi turbocharger replaced the Garrett T03 for quicker spoolup, resulting in higher torque at lower rpm (170 @ 2,400). Compression ratio dropped to 8.0:1 for the turbo engines and 8.9:1 for the 2.5L TBI engine; the 2.2 used a milder cam to smooth the idle, cutting valve overlap time by 30%.

A common single-piece tuned long runner intake manifold replaced the log manifold of the Turbo I and the two-piece manifold on the Turbo II. Turbo II and later IV intakes were black and had a charge air sensor; Turbo I intakes were silver and had no charge air sensor. This would continue through the end.

New programming eliminated the air charge temperature sensor for the Turbo I, calculating air temperature from other variables instead.


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 Turbo I moved to the 2.5 liter engine, and boost went up by 2 psi, raising output to 150 @ 4,800 (180 lb-ft @ 2,000). The turbocharger exhaust was enlarged, and the throttle body was gained automatic cable locks. The 2.5 Turbo I now shared the Turbo II's internal cooling. The air cleaner went from round to oval, and the Turbo I wastegate control was revised, providing initial boost at a lower speed, and more boost at medium and high speeds.

All the turbo engines gained a new throttle body with throttle levers which locked cables into place, and a larger idle air control passage.

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).

Former Turbo II cars started using Chrysler/Garrett's pioneering 2.2 Turbo IV, which dropped the wastegate entirely; the Garrett VNT25 variable nozzle turbo used moving blades to vary boost. The engine made the same 174hp as the Turbo II it replaced, but slashed "turbo lag." Early problems appear to have been due to a manufacturing defect.


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.

"Shelby's" VNT engine became factory production. 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.

In this year, the 2.2 Turbo I was used in the LeBaron, Daytona, Spirit, and Shadow - with manual transmissions in all four, and with automatics in LeBaron and Daytona.

Chrysler added balance shafts to its turbo engines; they had previously only been used on the 2.5. They also started using a new air cleaner and box, with an integrated turbocharger pressure bypass valve (to quickly vent boost pressure if the throttle suddenly closed), a cleanable oil-vapor foam element, a smaller housing, and a better oil separator for the PCV system. The company claimed in its "annual changes" guide to be using sequential fuel injection on both the 2.5 Turbo I and the 2.2 Turbo IV; this allowed a steadier idle and lower pollution.

1991The 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). This engine has sequential injection and was a technological leap forward in many other ways. It was dropped after the 1992 model year, at least within the US.

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.

The last year for the Chrysler turbocharged engines. The 2.2 itself only lasted until 1994. For 1993, the Mitsubishi 3.0 liter V6 replaced the turbocharged four-cylinders in the Dodge Shadow and Daytona and Plymouth Sundance and Duster.


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.


Minivans switched to a stroked (2.4 liter) Neon engine, rated at 150 hp - a more fuel-efficient engine with an extra 25 horsepower.

From "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."

1996The final year of the Chrysler 2.5, rated at 100 hp and only used in the rear-wheel drive Dodge Dakota pickup - complete with a motor mount bracket from the FWD cars. The 1997 Dodge Dakota switched to the venerable 2.5 liter AMC engine, which produced 125 hp with similar torque, thanks to multiple-point fuel injection; the main advantage of this over the 2.4 was likely having been designed for rear drive from the start.

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.

The first USA Chrysler turbo engine since the 2.2 is produced. The 2.4 Turbo has an intercooler and makes at least 220 horsepower, with strong torque as well. In the lightweight Neon, it goes to sixty in about 5.6 seconds, finally beating the Spirit R/T's time. In the heavier PT Cruiser GT, where it is sold with both manual and automatic transmissions, it's good for 0-60 in around 7.4 seconds.


A 180 horsepower version of the 2.4 liter engine is added for the PT Cruiser, to allow a higher-power car without the full stiff-suspension GT treatment.


The 2.4 turbo was modified for the 2006 PT Cruiser GT, going up to 230 hp, and retuned for the PT (since it was no longer shared with Neon). It had a new cylinder block and
head design changes, as well as a stronger crank and piston cooling by oil
jets; the turbocharger, which tended to overheat in the earlier cars, was both oil and water cooled. Acceleration improved and "dead spots" disappeared.

2010The last PT Cruiser is built, and the 2.4 liter four-cylinder engine is dropped; it would be the last ever Chrysler Corporation-designed four cylinder engine.
Key 2.2 - 2.5 engine links

Chrysler 1904-2018

Spread the word via <!--Tweet or--> Facebook!

We make no guarantees regarding validity or accuracy of information, predictions, or advice - .
Copyright © VerticalScope Inc. All rights reserved. Dodge, Jeep, Chrysler, Ram, and Mopar are trademarks of Fiat Chrysler Automobiles.

See less See more
1 - 1 of 1 Posts
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.