How were early 70’s V8’s so large yet relatively lacking in power

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How is it possible with the Chevy’s and Caddy’s with their pure American 6 litre V8’s didn’t get past 300 horsepower.

It seems so implausible that such a massive engine was so inefficient.

In: Engineering

13 Answers

Anonymous 0 Comments

Before the seventies the american solution to more power usually was increasing the displacement without any improvements to the technology. In 1971 there was a massive oil crisis that forced the world, including the US to restrict the fuel consumption of cars. The sudden change was massive and there just wasn’t any way to make power with the new restrictions in place. Especially with the big V8:s.

Anonymous 0 Comments

6 liter? Oh my sweet summer child…my mom’s car was something north of that and made (officially) 325 hp. Nobody cared much when gas was 25 cents a gallon.

The real answer is market dominance – there wasn’t much incentive for change beyond style and marketing efforts propping up the juggernauts of “the big three”. The cars of the 60s were essentially cars of the 40s layered with a lot of marketing and a smattering of technical improvements.

Emissions and safety regulation, fuel price apocalypses, and losing their markets to foreign competition that had leapt ahead in efficiency and quality finally lit a fire under them but it took a very long time to do it.

Anonymous 0 Comments

These engines still made massively more power than their European competitors at the time because even though they were horribly inefficient, they were huge. A 455 cubic inch Buick from 1970 made 510 ft/lbs of torque and 360 hp by virtue of being so large.

The mechanical control systems that fed the engines fuel and spark were pretty terrible, and only worked passably well at mediocre engine speeds. A carburetor basically dribbles gas into the top of the engine at approximately the right amount. The points that fired the coil were even worse at their job. Think of flipping a light switch as fast as you can – you can do a pretty good job of it at slow speeds, but as you try to go faster things get more and more irregular until you break something.

Electronic control of the coil didn’t become common until the mid-70s, and good computer control of the fuel not until the mid-80s. These two improvements brought massive power and efficiency increases with them immediately.

Source: am a Master mechanic specializing in service and repair of cars from this era.