Over the years, American automakers have made some of the most innovative engines. These include the famous flathead Ford V8, which changed the way people think about engines in the early part of the 20th century, and the small block Chevy, which you can still buy as a crate engine today.

It certainly isn’t all about the V8, either, with some of the most reliable inline-6 engines and some of the most advanced turbocharged engines also in the mix. Unfortunately, between all of these engineering marvels are a fair few duds too. Each of the big three have been guilty of this, forcing some underpowered, unreliable scrap onto the buying public from time to time.

10 Buick 3800 V6

Renowned for making large, lazy cars, this is a large lazy engine. It doesn’t match some others for displacement, but this is a transverse mounted engine.

So it adds a heap of weight to the front of whatever land yacht it gets planted in, then proceeds to underwhelm everyone. With just shy of 200 horsepower, this 3.8 liter engine is making around 50 horsepower per liter, not bad if this was from the 70s, but Buick were using this engine right up until the late 00s.

9 Ford 2.5-Liter HSC

Initially, this was developed during the 80s to be a more economical option as a 2.3-liter, but naturally Ford repurposed it and continued to shove it into the Taurus way into the 90s

It was already outdated technology in the 80s, having a cast iron head in a time where other manufacturers were already experimenting with aluminum alloy blocks. It is therefore exceptionally heavy for a transverse mounted engine (doing nothing for handling) and runs out of puff at around 5000 rpm, thanks to the fact that they designed the thing to be as durable as possible.

8 PRV V6

This did duty in a host of European cars and in all fairness to it, it did a respectable job for the most part, but the one and only American (ish) car it was put in, got ruined by it.

The DeLorean DMC-12 was supposed to be the most futuristic sports car back in the 80s, it was supposed to be what the Tesla Model S became today. Unfortunately, the rotary engine that was supposed to be mounted mid-ship never made it into production, so they scrambled to find a replacement, and this was it. Making only 130 horsepower, and mounted in the rear, it ruined both the performance and handling of the DMC-12 in one fell swoop.

7 Iron Duke

With an iron head and block, this was a durable engine, it was also incredibly underpowered, hopelessly inefficient and did we mention it was all made of iron, so yes, extremely heavy for an inline-4.

Then, GM had the cheek to put it into a Camaro, one of the most ridiculous things any manufacturer has done in decades. Today, it makes for a useful boat anchor.

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