Harley Evo vs Twin Cams: The Everlasting Battle!

Harley Evo vs Twin Cam has been an everlasting battle since it began during the late 90s. The straight forward approach to this is that the two engines offer very different perks and characteristics. That is why we have decided to explain which one is best for you and why.

Let’s dive in to know more about the in-depth differences based on several noteworthy factors.

Differences Between Harley Evo vs Twin Cams

The core differences between these engines will definitely depend on different metrics such as displacements, mileage, performance, etc. Let’s see what more makes this comparison a neck to neck battle:


Harley discovered the highly rebuildable Evolution engine otherwise known as the Evo engine back in 1984. Currently, they come in 883 cc, 1100 cc, 1200 cc, and 1337 cc versions.

Twin Cams came into being during 1999. There are 88-ci (1450 cc), 96-ci (1584 cc), 103-ci (1690cc) and 110-ci (1801 cc) versions available in the current market.


The first notable difference lies in the name. Twin Cam has two cams, one in each cylinder. Each of them has two lobes. The cam drive is a silent chain.

The Evo has only one cam with four lobes and their cam drive is in gears.

Pushrod Angle

It doesn’t matter how an engine is designed, pushrods will always have that one specific purpose. That is transferring motion from the lobe of the camshaft to the valve.

We know that the lesser the cam, the higher the pushrod angle. So Evo engines have higher pushrod angles because of having one cam. On the contrary, the Twin Cams have a lesser pushrod angle due to having two.

Lesser pushrod angle permits more cam lift. Through the two cam system, Harley was able to introduce bigger and powerful motors. They didn’t even have to compromise the reliability of the engine for this improvement.

Oiling System and Combustion Chamber

By the late 90s, Harley had brought significant changes aiming stability because they realized that the oil has to go through an extreme mechanical load, quicker response, and high operating temperatures.

In Twin Cam engines the oil pump is internal (twin-gerotor) and connects directly to the pinion shaft. The oil tank is below the transmission assembly. The combustion chamber is bathtub shaped and has higher compression.

And in the Evo engines, the pump is external and the route runs through the filters and a series of gears. The tank is around the battery, under the saddle. Lastly, the combustion chamber is D-shaped.

Availability of Spares

Another common concern among Evo users is the availability of spares. Any person going for an Evo must always consider the availability issue. Often the local dealership isn’t able to provide spares for the Evo.

Twin Cam users may also face spare part availability issues, as this problem differs from region to region. But Evo users are most likely to face it due to the engine belonging to an older lineup.

Don’t let this make you shy away from your engine of choice. Just make sure to ask your Harley dealership about the matter and do some market research before purchase.

Transmission and Vibration

If you have ridden both an Evo and Twin Cam, then you already know that the two engines vibrate very differently. Twin Cam’s have a direct rubber mount attachment to the transmission casing.

But the Evo transmission is displaced from the motor. Therefore they give a more rugged and muscular feel through their strong vibrations. Many people find this exciting and worthwhile. So if you are someone who finds smoother vibrations to be boring then Twin Cams aren’t for you.

But if you are planning for long rides on your bike then be aware of the Evo vibration, which may start to grow upon you as you travel for longer periods of time.

Mechanical Reliability

Both bikes are reliable. Harley has done a good job designing them both to be reliable and fail-proof. But there is no denying that a Twin Cam has less of a mechanical hassle than Evo. Go for a Twin Cam if you’re not too mechanically inclined and wouldn’t want to work on your bike with a wrench. There is no waste of sparks because the ignition system has dual coils.

Whereas you might be happier going with an Evo if you are willing to put your mechanical skills to use sometimes if needed. This is because they have a simpler structure and anatomy that is moderately easy to workaround. Here, some sparks are wasted since the ignition uses a single coil.

Cooling And Other Differences

In terms of mechanical technology, the Twin Cams have better braking, sealed wheel bearing, and a better rear shock absorption system. Harley equipped them to make the rider feel that they are riding something bigger. Twin Cams also have more surface area and spraying system for efficient cooling.

The Evo, on the other hand, has a less efficient cooling but enough for weekend trips and local rides. If you’re an old school Harley guy who loves the feel of the muscle and the shake then this is your perfect match. Nothing like the beautiful throttle response of an Evo!

Lastly, it all comes down to your personal preference of style. The sort of engine you choose has a lot to do with what sort of personality your bike is going to have. Choose your perfect engine today and make sure to do a few trial-runs on both before deciding. You can never go wrong with either of the engines.