As another definition states, the shovelhead engine is a type of V-twin engine that was manufactured by the Harley Davidson Motorcycle Company between 1966
and 1984. As with all Harley-Davidson motors, the Shovelhead has a distinct sound, and is still quite desirable as a power plant. The motorcycle parts company known as S&S has come out with a "retro" Shovelhead style of motor, thus allowing people who don't want to mess with the motor's notorious headaches can own one that doesn't cause nearly as much problems. The original Shovelhead motors can be cantankerous, but if taken care and properly maintained, they can also last for years. UNLIKE some other definitions here, Shovelheads are not necessarily for people who "can't afford a new Evo". There are quite a few folks who enjoy the older bikes, as they were from a time when it wasn't a passing fad to own a Harley. This is like saying someone who owns a 69' Camaro only does so because he can't afford a Cadillac Escalade. Just because you can afford to buy something new, that doesn't necessarily make it better. Evo engines that came out in 1985 and later on Twin Cam engines are nice, durable and reliable motors that don't need constant maintenance. This makes it nice for the crowd that bought a bike to fit in with the neighbors. But if you want to learn about history, and learn the inner workings of your bike, get a Shovel. You will get a history lesson as well as learn how to work on your bike, but the end result is a ...

The Harley-Davidson Evolution engine, or Evo, is sometimes also called the Blockhead. It is an air-cooled, 45 degree V-Twin motorcycle engine manufactured by the Harley-Davidson Motor Company since 1984, with an 82 cubic inch (1,340 cc) displacement, replacing the "obsolete" Shovelhead engine, until 1999 when it was replaced by the Twin-Cam 88. Most analysts consider the Evolution to be the engine that saved Harley-Davidson from certain bankruptcy.

Line of American motorcycles first manufactured in 1903 by William Harley and Arthur Davidson that are nowadays generally overpriced and underpowered.

Harleys are commonly referred to as "hogs," which is an allusion to the deep, throaty rumble the typical Harley exhaust emits. The loud exhaust noise is the basis for countless "all bark and no bite" references in relation to typical Harley engine performance. "Hog" is also an acronym for "Harley Owners Group."

Harleys utilize the antiquated and inefficient V-twin engine design, which is a Harley trademark in much the same way tumors are a trademark of cancer victims. While even older V-twin engines boast an excellent amount of low-end torque, most V-twin engines redline at about 5000 to 6000 RPM which severely hampers any effort made to achieve quick acceleration. In contrast, many sportbikes redline at 10000 to 15000 RPM--double the amount of torque, which means you can accelerate harder for a longer period of time before having to change gears on a sportbike.

Despite advances ...

Line of American motorcycles first manufactured in 1903 by William Harley and Arthur Davidson that are nowadays generally overpriced and underpowered.

Harleys are commonly referred to as "hogs," which is an allusion to the deep, throaty rumble the exhaust pipes emit as well as the amount of gasoline they typically consume. The loud exhaust noise is the basis for countless "all bark and no bite" references in relation to typical Harley engine performance. "Hog" is also an acronym for the Harley Owners' Group.

Harleys utilize the antiquated and inefficient V-twin engine design, which is a Harley trademark in much the same way tumors are a trademark of cancer victims. While even older V-twin engines boast an excellent amount of low-end torque, most V-twin engines redline at about 5000 to 6000 RPM which severely hampers any effort made to achieve quick acceleration. In contrast, many sportbikes redline at 10000 to 15000 RPM--double the amount of torque

What do you really need to know?

QUAD 4 simply means a 4 valve per cylinder 4 cylinder engine Oldsmobile produced, and GM put in various cars from 88~94.

A few facts: the QUAD4 was produced from 88~94. While a lot will still refer to the engine that replaced it as a QUAD4, it is not. It became the "Twin Cam". While I can't get into GM's Engineer's heads on the why, the fact you can not bolt a 95 right in where anything from 88~94 was is probably the main reason. Having said that, the basic engine was very much the same from 88~2002, which is why most people will refer to the any 2.3L or 2.4L in those years as a QUAD4. Why does it matter? Well the fact is when Olds (all the engines are Oldsmobile motors byt the way, regardless of the make its in) first made the motor, which was prior to the production model in 1988, they were making 750HP with a 2.2L version of it. (An Andretti drove the indy car it powered to more than 226mph laps at Indianapolis.)

So, for most of us what do we care? We care that we can get v8 power from a 4 cylinder with 4cyl economy when we can keep our foot out of it.

So, why does it get bashed all the time. Well like anything else there were some growing pains which did include some engine failures. More or less those problems have been resolved. Even in the older configurations the most significant issues have readily available fixes.

So, what should I look for? In a perfect world you would want a post 94 block mated to a pre 94 HO head...