86 S10 Head Bolt Torque 2.5 Iron Duke License Plates Ending

While not exactly providing a thrill of a driving experience, the Duke served all these platforms humbly and reliably.

Derided for being anemic at best, and noisy when pushed, the Iron Duke was nobodys favorite engine, forever juxtaposed with the tire-shredding power of the late Muscle Era, which had just drawn to a close.

Double-digit power numbers dont really inspire loyalty or confidence in any potential buyer, but in the midst of the Malaise Era, there werent many practical alternatives.

But what has this engine done to earn such a groanworthy reputation - and does it really deserve all the hate.

Though it only lasted from October 6th to the 25th, it would have lengthy and costly effects on Israels allies, one of which was the United States.

86 S10 Head Bolt Torque 2.5 Iron Duke License Plates Ending

This also resulted in policies like odd-even fill-up days, which only allowed people with license plates ending in an odd number to fill on odd days, and vice versa.

By the end of the embargo in March of 1974, the price for a barrel of oil had risen almost 400, and the price at the pump reflected it.

The Clean Air Act of 1970 put the squeeze on the automotive industry to reduce hydrocarbon, carbon monoxide, and oxides of nitrogen by 90 percent, by the year 1975.

This legislation imposed considerable tax burdens for purchasing passenger cars on a sliding miles-per-gallon scale, with greater penalties as efficiency dropped.

The primary burden fell on large passenger cars, which manufacturers quickly lost interest in producing.

Thus, the SUV market was born; although they were often comparably, or even less efficient than full-size sedans, they became the cheaper option, and could still use the existing larger engine designs.

In order to meet this demand, and adjust to the new EPA standards, the industry would have to invest in some fresh engineering.

At the time, the smallest displacement engine being produced by the company was 350 cubic inches, or 5.7 liters.

There was a lot of efficiencies to be gained by reducing the number and size of the cylinders, which would then require less fuel to run.

Engineers considered a number of options: new V8 engines with less displacement, a 90-degree V6 or V4 based on existing V8 designs, an inline four-cylinder (L4) based on one bank of an existing V8, an S-4 incorporating cylinders 1, 4, 6, and 7 from an existing V8, a brand new L4, and a brand new inline-six.

Their self-described goals for this engine were as follows: minimize noise and vibration, maximize usable power, and achieve excellent durability, driveability, and fuel economy.

An internal review revealed that GM do Brasil was already producing a 2.5L L-4 engine with a head start on these operating characteristics, so this became the starting point for the new Pontiac engine.

Although they utilized similar design principles, the engine which would ultimately become the Iron Duke did not end up sharing any parts with its South American cousin.

It was also used in the compact Ventura, which became the Phoenix the next year.

All of these cars were altered forms of what were originally Chevrolet models (the Vega, Monza, and Nova, respectively), so in order to bolt up correctly to the transmission, the Iron Duke needed to use the Chevrolet bellhousing pattern, rather than the one shared by Pontiac, Buick, and Oldsmobile.

In 1980, GM began to sell Iron Dukes to AMC, which utilized it as a base engine for their Spirit, Concord, Eagle, and Jeep CJ.

This continued until 1984, when AMC replaced it with a 2.5L 4-cylinder engine of their own design.

Chevrolet powered their Astro, Celebrity, Citation, S-10, S-10 Blazer, and Lumina with it.

Buick put it in their Skylark, Skyhawk, Somerset, and Century.