When the third-generation Camaro rolled around for the 1982 model year, fans were shocked. In the most affordable variant of what used to be the last chest-thumping cubes-over-brains pony car of the ’70s sat a four-cylinder engine generating just 90 horsepower. Sure, the new car looked great, still had an available small-block Chevrolet V8 on deck, and featured one of the coolest speedometers ever fitted to a car, but that base-spec powertrain was downright insulting.
While 90 horsepower is two more horsepower than a base-model 1982 Mustang could muster, early fox body Mustangs could weigh as little as 2,608 pounds. The Iron Duke (that’s the name of the engine; I’ll describe how this pathetic lump came about in a sec) Camaro weighed 2,864 pounds, and as a result, it had a substantially worse weight-to-power ratio than the Mustang. Nothing says sports coupe quite like 31.8 pounds per horsepower, right Chevrolet?
For the record, that’s a worse weight-to-power ratio than a 1983 Chevrolet Chevette, the cheap and cheerful chariot of pizza joints and small auto parts deliveries. Mind you, many younger readers didn’t get to experience the sloth of a Chevette firsthand, so let’s give more modern context. If we draw the Chevette’s subcompact lineage out to the modern day, we eventually arrive at the Chevrolet Sonic, a perfectly respectable subcompact car. Since the most powerful Sonic had a power-to-weight ratio of 21.9 pounds per horsepower, the Iron duke Camaro would be the equivalent of a 2011 Camaro having fewer than 176 horsepower while maintaining the same curb weight as the V6 car of the time. See a problem here? The word “performance” wasn’t anywhere in the Iron Duke Camaro’s vocabulary. What the hell happened?
The 1982 model year marked the first time a Camaro was available with a four-cylinder engine, and since GM’s attitude towards small cars at the time was something along the lines of “fuck ’em,” the General wasn’t playing with a full deck in the small-bore table game. In fact, Chevrolet only had two grown-in-Detroit four-cylinder engines at their disposal for the start of the 1982 model year. There was the 88-horsepower 1.8-liter four-cylinder engine found in the Cavalier, and then there was a second economy engine.
I’m talking about the Iron Puke, excuse me, Iron Duke 2.5-liter four-cylinder engine that GM made by starting with a cost-cut premise and then doing the exact opposite. According to a 1977 SAE document titled “Pontiac’s New 2.5 Litre 4 Cylinder Engine” by John M. Sawruck, The General first considered a wide variety of solutions.
With the advent of the oil embargo in late 1973, General Motors recognized that future American automobiles would be radically different from those previously built. As part of the realignment of General Motors products, Pontiac Motor Division began to examine the potential for producing engines smaller than the 350 In3 – 400 In3 – 455 In3 V-8’s then being produced. Engines considered included:
(1) New, smaller V-8’s from 250 In3 to 381 In3.
(2) A 90 V-6 from one of the existing V-8’s.
(3) A 90 V-4 from one of the existing V-8’s.
(4) An in-line four (L-4) made from one-half of an existing V-8 in a fashion similar to that of the 1961 Tempest L-4.
(5) A S-4 which had cylinders 1, 4, 6, and 7 from one of the existing V-8’s.
(6) A new L-4.
(7) An in-line six version of a new L-4.
From there, engineers decided to look at what foreign GM brands were doing. If overseas branches were making their own four-cylinder engines, why not just bring those to America? Well, the engineers in Detroit liked the smoothness of the Brazilian-spec Chevrolet 153 2.5-liter four-cylinder engine used in the Opala so much that they decided to copy the same bore, stroke, and bore spacing wholesale. However, because of reasons only known to GM, those are just about the only things the American engineers took from the Brazilian design.
Alright, so after a great deal of anguish, we now have some basic characteristics. Are we going with at least one overhead cam? Are we getting daring and shooting for electronic fuel injection? Will this engine embody the pioneering spirit GM had in the ’60s? Absolutely not. Instead, GM set about developing what it called the “formula engine.” Now, this doesn’t have anything to do with open-wheel cars, but rather, a set of goals established by an internal team that go as follows, in the words of GM:
- Minimize noise and vibration.
- Maximum usable power.
- Excellent durability.
- Excellent driveability.
- Excellent fuel economy.
That’s it. That’s the list right there. While this sounds promising at face value, some of the definitions and methods of achieving certain goals weren’t exactly groundbreaking, especially in the face of Japanese competition. With goal number one achieved by certain bore and stroke dimensions alone, let’s dive into objective number two. Here’s what GM had to say about “usable power”:
Usable power would be defined as power that would be available at lower engine speeds. This power assists in standing start accelerations, entering freeways, and when passing. This concept of small engine power differs greatly from that of most small engine manufacturers. Most small engines are tuned for high horsepower output at high rpm. It was felt that the Pontiac philosophy would result in a more pleasing vehicle, particularly in view of the 55 mph (88 kph) speed limit. Benefits would include the ability to use low numerical axle ratios which would result in lower engine speeds and less powertrain noise being generated.
Ah, I think the word they’re looking for is torque [Ed Note: If you mention RPM, like the document did, then it’s fine to say “power,” since power is the product of torque and RPM (divided by 5252). -DT]. While low-end grunt is what most drivers feel most of the time, merging and passing scenarios require a bit more flexibility. Because the Iron Duke wasn’t initially made to rev past 4,500 rpm, its power and torque curves never crossed.
Trade too much puff up top for low-end torque, and when a driver mashes their foot on the throttle to merge, they’ll get the sensation that the harder they push, the less quick the car feels. This is fine in a vehicle with no sporting pretense whatsoever, but in a rakish two-door? I don’t think so.
Now, to the four-cylinder engine’s credit, it was a long-lasting engine in most applications. Sure, the Iron Duke Fiero didn’t launch with the correct dipstick, but we’ll gloss over that for now since 2.5-liter S-10s are still kicking about. It was also perfectly adequate around town in most applications. However, the goals of the Iron Duke were completely incompatible with the high-testosterone, low I.Q. goals of the Camaro. It was a fine engine for an S-10 or a Citation, but it just didn’t post the numbers needed for a relatively heavy sports coupe. It gives off the same aura as a bodybuilder struggling to open a pickle jar, an innate look of all show and no go.
Unsurprisingly, road tests of the Iron Duke Camaro are thin on the ground, although it’s not hard to gather others’ general thoughts. In an early Motorweek preview drive of the third-generation Camaro in V6 form, they noted “Off the line, our V6 car wasn’t too responsive. That makes you wonder about the four-cylinder as a practical alternative.” In a full road test of a 1982 Camaro, Motorweek then went on to say that “Although the base line Camaro can be had with a four-cylinder, we wouldn’t recommend it.” On a more glaring note, GM Parts Center notes that the Iron Duke Camaro “couldn’t go 0-60 in under 20 seconds,” and any result around that time is deeply unsporting.
For 1986, the Iron Duke disappeared from the Camaro lineup, with GM’s LB8 2.8-liter V6 taking up the role of a base engine. While this wasn’t a rev-happy engine either, peak output of 135 horsepower and 165 lb.-ft. of torque represented a 46 percent horsepower increase and a 25 percent torque increase over the Iron Duke. Now that’s more like it. Then again, it’s not like the varsity football players cared. Their parents popped for the V8 anyway.
(Photo credits: Chevrolet, Pontiac)
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