Chrysler started making V6 engines quite late. If we ignore the 3.9, which was mainly an LA-series V8 with two cylinders taken off, their first V6 was launched for the 1990 cars; it had pushrods and two valves per cylinder to keep costs down and speed development. By the time it came out, Chrysler had a new, more amibitious engineering chief, Francois Castaing.
Castaing insisted on an engine with all the latest improvements—four valves per cylinder, overhead cams, and such, though not variable valve timing. Engineering work on this new design started in 1989, and finished within a stunning 40 months. This would be the 3.5 liter V6, whose development was led by Gordon Rinschler. It had a deep-skirt cast iron block and forged steel crank; John Hurst’s dual-valve rocker arm shaft system drove 24 valves from a single cam in each head. The valvegear was non-interference (free-wheeling)—the pistons would not hit the valves even if the timing belt broke.
Spark plugs were in the center of the combustion chamber, semi-Hemi style. There was no distributor; it used three coil packs, each of which fired two plugs at once (one unnecessary fire, one ignition fire). The new engine took midgrade 89-octane fuel, producing a then-quite-high 214 horsepower and 221 pound-feet of torque in 1993. The 3.5 was powerful, yet durable and generally trouble-free.
The 3.2 was an aluminum-block version of the 3.5 V6 made only for the 1998 to 2002 cars. It had a broader torque curve and ran on regular gas instead of midgrade. A smaller version, the 2.7, was created alongside the 3.2 and debuted at the same time for the new generation of big “LH” cars. For that generation, the 3.5 went from 214 to 250 hp and 250 lb-ft of torque, but still needed 89 octane fuel. Given that, the 3.2’s production of 220 hp and 222 lb-ft with lower displacement and regular fuel deserves some acclaim.
| Category | 2.7 Liter | 3.2 liter |
|---|---|---|
| Bore x Stroke | 3.39 x 3.09 | 3.66 x 3.19 |
| Compression | 9.71:1 / 9.9:1 |
9.5:1 |
| Power (hp) | 190 or 200 |
220 @ 6600 |
| Torque (lb-ft) | 188 or 190 |
222 @ 4000 |
| Max. RPM | 6464 or 6,600 | 6800 rpm |
| Fuel | 87 octane (regular) | |
The company released a power/torque chart of the 3.2 engine vs the prior 3.5 it was based on. The company did release a more powerful version of the 3.5 shortly afterwards, which raised the stakes to 250 hp; but the 3.2 was a rough match for the older 3.5 engine despite running on cheaper, lower-octane fuel. A later retuning like the one given to the 2.7 for 2004, which lowered peak horsepower but made more torque available at lower revolutions, would probably have made for a more compelling chart—but it was not to be.
The 3.2, like the 3.5 it was based on, used a single cam in each head driving all four valves; it added some expense but also increased power. (The inner cam was used for the intake, the outer cam for exhaust; the two were chain-linked.) Though variable valve timing was getting increasingly common, the 3.2 did not have that technology.
It also added a variable intake system, changing the effective length of the manifold tubes to create a supercharging effect at various engine speeds. The engineers did not have to optimize the intake for either high-speed or medium-speed power; they could choose both.
From above, the 3.2 is almost exactly the same, visually, as the 3.5 liter engine it was based on. The induction and injection systems worked quite well, in the 3.5; there was no need to completely re-engineer them.
Valves were actuated by hydraulic center-pivot roller-type rocker arms in a cast aluminum head; the block was cast aluminum with iron cylinder liners. Fuel economy in the full sized Chrysler Concorde was a respectable 19 city, 29 highway with the four-speed automatic. That was quite good for a large car.
| 1997-98 Cars | Engine | hp | Octane | Car cost |
|---|---|---|---|---|
| Cadillac Catera, 1997 | 3.0L | 200 | Premium | $34,750 |
| LH series, 1993-97 | 3.5L | 214 | Mid-Grade | $24,270 |
| Intrepid/Concorde, 1998 | 3.2L | 220 | Regular | $24,000 |
| Ford Taurus SHO, 1996 | 3.4L | 235 | Premium | $28,250 |
The 3.2 liter engine didn’t make much sense to marketers, sitting right between the 2.7 and 3.5, and disappeared fairly quickly. That was a shame: the 2.7 did get considerably better mileage, but many people avoided it after teething problems with “sludge” which did not afflect the 3.2. The PCV system and a water pump seal appear to have been at fault for sludging the smaller 2.7. That said, the 3.2 was probably roughly the same cost as the 3.5, and while it took regular gas instead of pricier midgrade, fuel economy was probably almost identical to the 3.5; and 250 hp is substantially higher than 220 hp.
| 1997-98 Cars | MPG | HP | Fuel |
|---|---|---|---|
| 1997 Catera | 18/25 | 200 | Premium |
| 1998 Intrepid 3.2 | 18/28 | 220 | Regular |
| 1996 Taurus SHO | 17/26 | 235 | Premium |
| 1998 Intrepid 2.7 | 21/30 | 200 | Regular |
| 1999 Chrysler LHS* | 18/27 | 250 | Midgrade |
| 2001 Intrepid 3.5* | 18/26 | 250 | Midgrade |
* For 1998-99, the 3.5 was not available in the Intrepid or Concorde. The Chrysler LHS had a standard 3.5 engine but it was a larger car, with a longer wheelbase. The Chrysler 300M was smaller but had performance tuned gearing and accordingly lower mileage. All gas mileage figures are from the EPA using pre-2008 methods.
For more information on its basic design and history, see the 3.5 DOHC page.
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