The Mopar 2.2 Liter Engine
2.2 / 2.5 engine introduction
Dan Stern reported that the Slant Six and 2.2/2.5 liter engines were both products of the engineering genius of (among other people) Willem L. Weertman. He was Managing Engineer--engine design from 1955-62, Assistant Chief Engineer--Engine Design and Development from 1962-76, and Chief Engineer--Engine Engineering from 1976-87. This means he also had a large role in just about everything from the Slant 6 through the LA engines and the 426 Hemi. They pulled him out of retirement for the V-10 projects.
The 2.2 is one of the most reliable four-cylinder engines ever made, and in all its forms, from under 84 hp to 224 hp, was a long-lasting sturdy piece of equipment (if you were willing to pay for the occassional head gasket).
Generally, the 2.2 was fitted with either a carburetor (early years), a turbocharger with multiple-port fuel injection, or a single throttle-body injector. The most common was the "TBI" (single throttle-body injector), though the turbos were fairly potent. Multiple-point fuel injection (running at 42-64 psi) had been used on the turbocharged models before the cheaper but less efficient throttle-body injection system was created; the throttle-body cars used a lower pressure, 14.7 psi. The reason both for keeping carburetors as long as they did (and for keeping them on the Omni and Horizon for longer than on other models) and for using single-point injectors was cost; carburetors reportedly cost half as much as the single injectors, and of course four injectors cost far more than one. The downside was lower gas mileage, lower power, and a less competitive vehicle.
The multiple-port fuel injection engines (using four separate injectors rather than just one, firing into the intake ports rather than the throttle body so fuel would stay atomized and time delays would be minimized) did not spray fuel into all cylinders at once, but alternated the injectors to avoid wasting fuel. This allowed the turbocars to avoid the aspirator or air pump.
2.2 and 2.5 turbo information has been moved to a separate page; click here to visit.
General information
The 2.2 was introduced in 1981 as an all-new design, the first metric Chrysler engine. It was originally built at the Trenton Engine plant, which made the slant six and 440 RB. Though the two have some basic similarities, Pete Hagenbuch, who worked on both engines, wrote that "As far as I know there was absolutely no commonality between the 170/225 engines and the 2.2/2.5." The design philosophy may have held commonality, but not the actual design. See our interview with engine designer Pete Hagenbuch , which covers the 2.2 and other topics.
There are several different 2.2 blocks. They feature siamesed cylinder bores (no cooling in between), a short crankcase skirt, and partial open deck; it was designed to be machined by milling to achieve lighter weight, but uses a cast iron (rather than aluminum) block because aluminum technology at the time was not what it is now. The oil pump is mounted internally. High performance versions, such as the Shelby engines, have modifications such as .8 mm milled off the top of the deck surface. Even on the 225 horsepower 2.2 Turbo III version, the engines had a timing belt. One of the engineers explained: "I always hated belts, but the weight penalty for chains was as big a factor as cost." Oil sealing was also a factor. 2.2 liter engines are all noninterference designs, so they generally are not damaged when the timing belt breaks.
The early 1981-83 blocks weigh about 87 lb; the turbo block weighs about 90 lb. A special racing block (96 lb) was designed for IMSA racing, before the turbo block was available and before a Champion RS series rule change made the 2.2 noncompetitive.
Pistons are aluminum with steel struts, and rings are iron. Different years and engines (e.g. turbo I, turbo II) used different pistons. Mopar Performance sold a heavy duty oil pump for most of the 2.2's life, which can be handy in high performance situations.
The 2.2 liter engine was originally to be 2.0 liters, but the K-cars needed some extra power, so the engine was enlarged during the development. Priority was given to moving exhaust heat to the floor of the intake manifold, underneath the carburetor, to warm it up more quickly and get better cold responsiveness; the carburetor was moved as far back as possible to make it safer during a front-end impact, and also to make assembly similar to the 1.7 liter Volkswagen engines already used in the Omni and Horizon. This move made the spark plugs and oil filter easier to change. The distributor, belt adjustment, and power steering pump were also easy to access (reference for this paragraph: Chrysler Engines, 1922-1998.)
Carbureted models used a staged two-barrel carburetor, a Holley Weber design. Feedback units were used on domestic (American) cars, usually a model 6520 carb. Some Canadian and Mexican cars used a Holley Model 5220, staged nonfeedback dual venturi carburetor.
The 2.2 engine was brought out in 1981, and used an electronic feedback carburetor (except on turbocharged models); Chrysler phased in single-point, throttle-body fuel injection starting in 1985 (Laser, Lancer, LeBaron and LeBaron GTS, and Caravelle), with every car except Omni/Horizon and Turismo/Charger using fuel injection in 1986, and the final conversion, of the L bodies, in 1988. The electronic fuel control system on carbureted engines measured engine speed and load, starting condition, coolant temperature, throttle (open or closed), ambient air temperature, and output from the oxygen sensor to control ignition timing and adjust the air-fuel mixture at the carburetor. Engines with the 2.2 cut fuel during deceleration for better gas mileage, using a solenoid-controlled valve that opened during deceleration to allow more air into the idle system; it was also used to prevent “dieseling.”
Carburetors had one major advantage over fuel injectors: they cost far less, despite the seemingly greater complexity of the carburetor and its control systems. However, they could not provide the emissions control of fuel injectors, even single fuel injectors in the throttle body. Unfortunately, at the time Chrysler was spending as little as it could on emissions controls; had the company used multiple point fuel injection on all of its cars from the start, rather than EFI, its powerplants would have had more power, better gas mileage, lower emissions, and better responsiveness and idle quality, attracting more buyers and perhaps even making it possible to sell its cars at a profit in the late 1980s and early 1990s. As it was, the later EEK models were frequently dismissed by auto journalists as relics, despite their attractive pricing and, often, their advantages over Japanese and other domestic models.
The fuel injection systems were controlled by a pair of computers, the Logic Module and Power Module; the logic module controlled ignition timing, the air/fuel ratio, emissions control devices, and idle speed, while the power module translated the logic module's demands for air/fuel ratios and timing into signals sent to the fuel injector (altering the length of its pulse) and the distributor. Input from the knock sensor allowed the computers to retard timing as needed to avoid damage to the engine with (for example) low-octane fuel (on turbocharged engines, engine knocking was dealt with both by reducing boost and by retarding timing for the knocking cylinder — and only that cylinder). The logic module was adaptive — it could compensate for changes in operating conditions, including altitude changes (this had been introudced in 1982).
1986 saw a new “fast-burn” cylinder head that helped the air/fuel mixture to swirl from the ports (as illustrated below) for better combustion:
The 2.2 ranged in power over its life. In 1985, the carbureted version was rated at 96 hp (but only 119 lb-ft of torque). The fuel injected version started out at 99 hp / 121 lb-ft, with a high output version (for the 2.2 Charger, etc) at 110 hp and 129 lb-ft of torque. The 2.6 had more torque but comparable horsepower. The 2.5 started out at 100 hp and 136 lb-ft of torque, comparable to the 2.6, and would stay at roughly that power output through its life (except with a turbocharger fitted).
| 1982 2.2 | 1985 2.2 | 1986 2.2 | 1986 2.2 Turbo I | |
|---|---|---|---|---|
| Displacement | 2213 cc | 2213 cc/135 CID | 2213 cc | 2213 cc |
| Compression ratio | 8.5:1 | 9.0: 1 | 9.5:1 | 8.1: 1 |
| Horsepower | 84 hp @4800 | 99 @ 5600 | 97@5200 | 146 @ 5200 |
| Torque (ft/lb) | 111 lb-ft @2,400 | 121 @ 3200 | 122@3200 | 170 @ 3600 |
| Bore/Stroke | 3.44" x 3.62" | |||
| Coolant Capacity | 8.5L (9.0 qts.) | |||
| Fuel Recommended | Regular | Regular (87 octane) | Regular | Premium (91 octane) |
| Fuel delivery | Carb | TBI | TBI | MPI |
| Mileage (Aries stick) | 29/41 | 25/35 | ||
More details on the 2.2 and 2.5 blocks
James Corrigan wrote: The 2.5 has a deeper stroke than the 2.2, the 2.5 has a bigger crankshaft with a bigger throw. Basically this means if regular length 2.2 pistons were used with 2.5 crank, the pistons would pop out the top of the regular 2.2 block. So what Ma Mopar did in '86-88 was to build the tall block, basically a 2.2 block but with a higher deck so the pistons won't pop out the top.
In 1989 Mopar started using the common block, this was used for (all 2.2/2.5 engines) from here on. Strongest block to get, best to handle 300hp and all that. The block went down to the old 2.2 size, but to keep the pistons from popping out the top, this time they installed shorter (distance from crown of piston to wrist pin) piston heads. So now it has the 2.5 litres of displacement, with the big 2.5 crank, without the pistons coming out the top.
Which is better? I'd say it doesn't matter. Common block is more durable but at naturally aspirated (nonturbo) power levels it won't make much difference. If you were talking turbos though, I would definitely say common.
Tips and hints
Wes Grueninger said: Almost all radiators used with nonintercooled 2.2s, carbed, TBI, or T1, are identical in dimension, regardless of body style. They have a 22-1/4"x15-1/4"x1-1/4" 2-row core, 1-7/8x16-3/8 end tanks, a 1 to 1-1/4" inlet and a 1-1/4" to 1-1/2" outlet. This applies to 1981-89 models. N bodies, P bodies, and Dakotas use different radiators.
Hilary Paprocki wrote: The Purolator Pure One PL30001 oil filter is twice the size of the original filter and filters oil well. It'll fit your Shadow 2.2 and costs the same as the dinky stock number. I did notice a difference in the oil coming out.
Tim Mikolay wrote: For some reason on this model, and a GLH I painfully sold, I retorque the spark plugs AND the throttle body gasket bolts at every season change. They work themselves loose like a Harley. Also, with a new one piece valve cover gasket (first I've ever seen for this engine), a redesigned oil filler cap that doesn't leak and hose clamps on either end of the hose connecting the valve cover to the air filter housing (legendary for oil leakage), oil stays.
Regarding the swirl port (fast-burn) heads, there is a chunk of aluminum missing on the #two cylinder near the intake valve, around 1/2 inch long, 3/8 inch deep, and 1/16 inch wide. Derek Beland wrote that this is a locating point for the machines that process the head at the factory.
Some places to fix a rough idle:
- Check for fault codes
- Manifold gasket may leak, especially between the injector and manifold
- Check the heated air system (oven)
- Check timing and compression
- Are all coolant lines connected to the bottom of the intake?
- Oxygen sensor may not be working well but could still not be "throwing a code"
- Correct timing belt is attached (there were two, one with square notches and one with rounded notches, and they've been known to get mixed up at parts shops!)
- Check the vacuum diaphgram in the transductor can (carbureted engine)
- Plugs, wires, etc.
Performance
Mopar Performance used to list a supercharger for the carbureted 2.2 engine (P4349478). Development work was done at the Caroll Shelby Performance center, and it was manufactured by B&M for Chrysler. It was also listed in the B&M catalog, part number 90601 Dealer cost on this in 1987 was $1400! It made with the stock carb 130hp@5200 RPM. With the Weber carb (PN P4349300) the hp jumped to 155@5200 RPM. Despite the high cost, the supercharger never made it to the output of the standard Turbo II package (174 hp.) (Thanks, Marc Medina!)
Chronology (courtesy of Aaron Karpinski, some additions by the Webmaster)
For photos and more 2.2 information, visit Aaron's Web site.
Note: we’ve moved out most of the turbo information to our 2.2 / 2.5 turbo engine page.
| 1981 | This was the first year for the 2.2 liter engines, built at Trenton Engine, which had made the big-block V8s. They developed 84 horsepower @ 4800 rpm and 111 ft-lbs of torque @ 2800 rpm. They gained popularity in the Plymouth TC3 Turismo and Dodge Charger 2.2, and were offered in just about every Chrysler 4-cylinder car. The first 2.2 featured a cast iron block with aluminum pistons, overhead camshaft and valves, and an aluminum cylinder head. In 1981, equipment included a two-barrel Holley electronic feedback carburetor, water heated intake manifold, and a computer that monitored engine functions and controlled the air-fuel ratio. A PPG pace car built on a Charger frame was made this year, witih a prototype turbo setup. |
| 1982 | Slightly different intake manifold (shorter runner, larger plenum), still 84 hp. Underhead flat removed from exhaust valve. Cam centerline changed, with new sprockets. TRW exhaust valve seats. New "D" intake manifold as a running change. A Plymouth Reliant was built with a prototype turbo engine, nearly identical to the actual Turbo I (which was never used on a K-car.) Stock added to block between cup plugs, below manifolds. Teacup oil filter. |
| 1983 | The first year for the A511 "G" casting cylinder head, slightly more air-flow then the older head. Using .030" higher pistons for an increased compression ratio give it 94 hp. Underhead flat removed from exhaust valve. New exhaust manifold, flanges removed from sprockets (running change), low load valve springs, anti drainback valve added.
Also the first year for the Shelby engine in the Dodge Shelby Charger - the same as the regular engine except for slightly richer carb jets, a .030" milled engine block and slightly different engine computer, yielding107 hp. This year was the debut of the A465 five-speed manual, replacing the A460 four-speed in most vehicles (the A465 merely added an overdrive gear, and had an extended case cover to make room). |
| 1984 | The regular engine develops 96 hp @ 5200 rpm, the Shelby engine 110, now offered in the Shelby Omni GLH (blocks cut .030" in late 1983). First year for the TBI (throttle body injection) engine (99hp @ 5600rpm, the highest it would ever go, with 121 lb-ft of torque). The head bolts were upgraded from 10mm to 11mm.
First year for the Turbo I engine - 142 hp. It featured Chrysler-engineered multi-point fuel injection, and a turbocharger with the wastegate set to limit boost to 7psi. This was only the second American front wheel drive vehicle with a turbocharger, after the 1979 Buick Riviera. Other changes include hardened inserts added to rockers, higher load valve springs (both normal and turbocharged engines), stamped rockers, lightweight crankshaft, oil pump relief riased to 70 psi, turbo oil drain boss added to block, removed lubrite from camshaft, oil pump relief raised from 60 to 70 psi. This was also the first year for the 525 manual transmission, used in the Daytona. |
| 1985 | The carbed engine makes 96 horsepower, TBI 99, the Shelby engine 110. Chrysler offers the Shelby engine in any Charger or Turismo with a 5 speed manual transmission. The Turbo I engine makes 146 hp and features a computer controlled wastegate set at 7psi with a new "transient boost system" that would allow 9 psi for a small amount of time. First year for the Shelby Charger Turbo.
The new 287 head replaces the 455 heads on carbureted engines, basically the same but with a new a/c compressor mount. Other changes: A590 (solid mount a/c) bosses on block and head, oil management block (running change), intake valve surface improved, 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), different oil pump rotor, oil pump relief back down to 60 psi, 8 bolt flywheel (late change), material added to head and block at oil transfer hole, 60 psi oil pump relief spring (again), late change to 8 bolt flywheel, .94 rotor oil pump (late change) |
| 1986 | The first year for the A515 "fast burn" cylinder head and notched "fast burn" pistons, designed to decrease emissions. Carbed engine 96hp, TBI down to 97hp, Shelby 110hp, Turbo I 146hp.
The first year for the 2.5 liter engine, using the same cylinder head as the 2.2, single point throttle body injection, a taller block and balance shafts in the oil pan. 100hp @ 4800rpm - which would be the same through its end. 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. |
| 1987 | Last year for the carbed engines, still 96hp. TBI stays at 97. A modified 2.2 is used in the Dakota pickup - carbureted. First year for the A520 five speed manual. |
| 1988 | 2.2 TBI goes down to 93 hp, where it would stay until the end. Roller rocker camshafts are used in all 2.2 and 2.5 engines to replace the regular "slider" cams. A single engine computer replaces the dual setup. |
| 1989 | The new common block was used for turbo, standard, and 2.5 liter engines, saving money and giving base engines a stronger block; 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. The Turbo I setup now used 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 pipe was unlarged for better airflow. Throttle body injected engines got a new injector and higher fuel pressure. Cam drive sprockets and belt were changed to a quieter design. |
| 1990 | The 2.5 TBI engine has 7 more horsepower and more torque than the 2.2; it would stay at 100 hp through its lifespan. A single board computer arrives. |
| 1991 | The Turbo III is put into production and used in the Spirit R/T and Daytona R/T, with 225 horsepower. A high torque 2.5 Turbo is used with automatics. |
| 1993 | Export 2.5 liter MPI engine produced with 106 hp. 2.0 liter engine, destined to replace the 2.2, enters production in the brand-new 1995 Neon. Mexico gets a multiple-port injection 2.5 with 106 horsepower, while the US gets a multiple-port injection 2.5 flexible-fuel engine that runs on ethanol. |
| 1994 | 2.5 MPI drops to 103 hp. 2.2 TBI drops to 92 hp in its final year. The turbos are all gone now. |
| 1995 | The 2.2 and 2.5 finally drop from production as the 2.4 liter version of the Neon 2.0 is used in the Caravan and Voyager. The Dodge Dakota, the last remaining vehicle to use the 2.5, switches to a 2.5 liter AMC engine producing 125 hp, in a final attempt to confuse Mopar fans; the AMC 2.5 will be eliminated in 2002, replaced by the 2.4. The 2.0 is designed with some of the same dimensions as the 2.2 in order to reduce tooling costs; it produces 132 hp and 129 lb-ft of torque, while the 2.4 goes up to 150 hp. From shelbycsx.com: “According to Peter Badore, a former Chrysler employee, 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.” |
| 2002 | The end of the 2.0 and 2.4 engines is announced, with both being replaced by a "joint effort" engine lineup initially designed by Hyundai, and substantially redesigned by both Chrysler and Mitsubishi. Coincidentally, the turbocharged version of the 2.4 also appears. |
| 2005 | The last Neon is built, and the 2.0 engines are relegated to export PT Cruisers; the 2.4 will be eliminated around 2007, while BMW is soon to drop the Neon-based 1.6 engine from their Mini, so the last traces of the 2.2 design appear fated to disappear in 2007 (earlier if the PT swaps to the newer engines). The new 2.0 produces 148 hp, the 2.4 172 hp. |
Cam specs (courtesy Ed Treijs)
1987 (Slider) Cam specs
2.2 Standard 2.2 Turbo 2.5 Standard
Intake Opens (BTDC) 16 10 12
Closes (ABDC) 48 50 52
Exhaust Opens (BTDC) 52 50 48
Closes (ABDC) 12 10 16
Valve Overlap 28 20 28
Intake Duration 244 240 240*
Exhaust Duration 244 240 240*
*I think this should be 244--the 2.5 is just a 2.2 N/A retarded 4 degrees....
Common repairs
Most repairs are covered on our central repairs and troubleshooting page. However, we do have a collection of odds and ends on our 2.2/2.5 liter repairs page.
See our interview with engine designer Pete Hagenbuch, which covers the 2.2 and other topics.
