The horsepower ratings of Harley-Davidson big-twin engines range from 7 HP up to 165 HP. However, it’s safe to say that the performance of most modern Harley-Davidson motorcycles falls into the range of 60-121 HP.
If you want to find out more about the performance of each engine, you’ve come to the right place.
We at PowerSportsGuide have compiled the key specifications of these engines into one Harley-Davidson horsepower chart!
How Much Horsepower Does a Harley-Davidson Have?
As a rule of thumb, an average air-cooled Harley-Davidson big-twin engine generates about 0.8-0.9 HP per cubic inch. In contrast, early (pre-1965) models only delivered 0.15-0.6 HP per cubic inch depending on the year and model. On the other end of the spectrum, you can find liquid-cooled Harley Revolution engines with amazing 1.7-2.2 HP/ci ratios.
Different types of Harley engines have been produced with different intake and exhaust architectures over the years. Therefore, the performance of each engine configuration has changed over time.
It’s also good to know that manufacturers typically release HP ratings, which are measured on the crankshaft. Because of this, the “real” HP of a Harley is influenced by many other factors including the transmission, driveline, and the rear wheel, which causes a small loss of power.
The general rule is that the measurement on Harley’s rear wheel is about 10-15% less than the rated engine HP on the crank. This power is often measured on dyno pads.
Due to these circumstances, determining the exact usable power of a Harley engine is hard to impossible, since different bikes come with different features.
Despite this, we did extensive research to try and give a ballpark HP range for each big V-twin engine.
Let’s get down to the nitty-gritty and talk about the performance of legendary Harley engines in detail!
How Much HP Does an F-Head Harley-Davidson Engine Have?
The F-head V-twin is considered the first long-lived V-twin Harley-Davidson engine manufactured from 1911 to 1929.
The predecessor of that engine was the single-cylinder Harley F-Head 35” rated at 3.9 HP introduced in 1903.
In 1909, the manufacturer decided to double the performance of their bikes by using two cylinders. Due to its V-twin design and atmospheric inlet valves, the new engine was often referred to as the “atmospheric Harley V-twin”.
This 49.5 cubic-inch power source featured two cylinders in a 45-degree configuration and was rated at 7 HP.
By 1911, the atmospheric inlet valves of this engine were replaced by a more advanced push-rod and a rocker arm.
This new engine was labeled F-Head 61” and could already rev higher resulting in engine power of 11 HP. The family was expanded with the F-head 74” in 1922.
How Much HP Does a Flathead Harley-Davidson Engine Have?
Flathead Harley engines delivered about 22-55 HP depending on the year and model. The first engine in this breed was the 1929 Flathead 45” rated at 22 HP. Later the Flathead engine family was expanded with Flathead 54”, 74”, and 80” engines, which produced approx. 30-55 HP.
Surprisingly, these ancient engines featured a “total loss” oil system, meaning that once the oil went through the engine it was left behind on the ground.
They were also often called “side valve” engines referring to their unique valve design.
The 74” and 80” engines shared the same bottom end and stroke, but the latter came with bigger bore cylinders.
Flathead engines underwent many changes over the years and remained in the lineup until the ‘50s.
Among the latest Harley Flathead engines was the 54” (833cc), which made its debut in the 1954 KH. The upgraded version of this engine was carried over to the more advanced 1956 KHK.
This air-cooled, Flathead 54” Harley V-twin produced no less than 52 HP at 5,500 RPM.
After the ’56 season, the manufacturer dropped Flathead engines from its 2-wheel motorcycle lineup but continued to use them in three-wheeled Harley Servi Cars until 1973.
How Much HP Does a Knucklehead Harley-Davidson Engine Have?
Knucklehead Harley-Davidson engines were rated at about 40-55 HP. This engine debuted in 1936 and was offered in two displacements: the Knucklehead 61” had 40 HP while the larger 74” cranked out 45 HP.
Harley’s Knucklehead engines got their name for the unique shape of their rocker covers.
They got some important upgrades including an advanced circulating oil lubrication system and overhead valves.
How Much HP Does a Panhead Harley-Davidson Engine Have?
Harley-Davidson Panhead engines produced 50-60 HP depending on their year and model. The smaller sibling in this family was the Panhead 61” rated at 50 HP while the larger 74” delivered 55 HP.
These engines inherited their bottom end from their predecessor but they got some innovative features such as internal oil lines and aluminum heads.
Later models saw some upgrades that resulted in a significant increase in horsepower.
How Much HP Does a Shovelhead Harley-Davidson Engine Have?
Thanks to their advanced design and features, Harley’s Shovelhead engines delivered about 60-70 HP.
The first engine in this line was the 1966 Shovelhead 74” (60 HP) followed by the 80“(65 HP) in 1978.
This engine configuration remained in production until the mid-‘80s.
How Much HP Does an Evolution Harley-Davidson Engine Have?
As the name suggests, the Evolution (a.k.a. EVO or Blockhead) engines were a great improvement over their predecessors.
This unit was not only the first Harley engine designed with Computer-Aided Design (CAD) but it packed many innovations as well.
Thanks to this careful engineering, Evo engines ran smoother and cooler and used less fuel than the outdated Shovelheads.
The general rule is that you can expect the performance of a Harley Evolution engine to be in the ballpark of 45-65 HP.
The first member of this family was the Evolution 80” rated at 50 HP. This engine was manufactured from 1984 through 1999 meanwhile its performance increased.
While most stock 80″ Evos produced about 50-55 HP with 60-65 ft-lbs torque, later models could reach a remarkable 60+ HP.
Besides this big-inch configuration, the manufacturer rolled out a complete series of Evolution engines, including the 54”, 67”, and 74” Evo. These power sources delivered 45-65 HP depending on their size and model year.
The Evolution 80” was discontinued in 1999, but its smaller brothers lived much longer in the Sportster models.
How Much HP Does a Harley-Davidson Twin Cam Engine Have?
You can expect the performance of a Harley-Davidson Twin Cam engine to be in the ballpark of 55-90 HP. To be more specific, the HP ratings of Harley bikes with different Twin Can engines are as follows:
- Twin Cam 88”: 55-62 HP and 70-78 ft-lbs of torque
- Twin Cam 96”: 60-66 HP and 75-82 ft-lbs of torque
- Twin Cam 103”: 68-75 HP and 80-85 ft-lbs of torque
- Twin Cam 110”: 75-90 HP and 90-115 ft-lbs of torque
The performance of Twin Cam engines varies widely since they come in many different configurations.
How Much HP Does a Harley-Davidson Revolution Engine Have?
Harley-Davidson Revolution engines can produce anywhere from 115 to 165 HP.
Revolution engines are unique factory-built liquid-cooled Harley engines introduced on the V-Rod model. These power sources were born out of a collaboration between Harley-Davidson and Porsche just after the Millennium.
Compared to traditional Harley engines the Revolution series was vastly different. They featured a 60-degree V angle rather than the conventional 45-degree configuration and featured a liquid-cooling system.
They also had a DOHC (Dual Over Head Camshaft) configuration and were fed by a fuel-injection system.
On top of that, they had a very short stroke, which made these engines capable of revving up to 8,000-9,000 RPMs. Their unique architecture and features made these units the most powerful factory Harley engines ever built.
The entry-level engine in the Revolution line was the 69” rated at 115 HP.
Its bigger brother, the Revolution 76” offered 125 HP with 85 ft-lbs of torque at the crank. The latter was released in 2012 for the 10th anniversary of the 69”.
By 2006, this Revolution Harely family increased to five models, including V-Rod, two Night Rods, the Street Rod, and the flagship VRSCSE² Screamin’ Eagle V-Rod.
The latter was actually a factory-modified V-Rod motorcycle, labeled as the Harley-Davidson VRXSE Screamin’ Eagle Destroyer. This purpose-built drag Harley delivered no less than 165 HP out of the box!
In experienced hands, it could make quarter-mile runs in less than 10 seconds on drag strips.
How Much HP Does a Harley-Davidson Milwaukee-Eight Engine Have?
The HP rating of Milwaukee-Eight engines averages anywhere from 91 up to 121 HP. This power source is available from 107” to 131” and sizes in between:
- Milwaukee-8 107”: 91 HP and about 100–112 lb-ft of torque
- Milwaukee-8 114”: 102 HP and about 110-125 lb-ft of torque
- Milwaukee-8 117”: 105 HP and about 124 lb-ft of torque
- Milwaukee-8 131”: 121 HP and about 108–112 lb-ft of torque
Note that these are the claimed HP and torque ratings at the crank, meaning that you can expect about 10-15% less on the rear wheel:
- Milwaukee-8 107”: 77-82 HP (@ rear wheel)
- Milwaukee-8 114”: 82-90 HP (@ rear wheel)
- Milwaukee-8 117”: 92-98 HP (@ rear wheel)
- Milwaukee-8 131”: 110-115 HP (@ rear wheel)
These engines come with the traditional 45° V-twin architecture and feature eight valves. They also use a combination of oil and air-cooling to keep the engine temperature down.
The most powerful stock Milwaukee-8 is the 131” boosted with Screamin’ Eagle Street Cannon mufflers.
This configuration offers an amazing performance of 121 HP with 131 ft-lb of torque out of the box.
If you are looking for more power, you can boost these engines with factory-installed Screamin’ Eagle performance kits.
Harley-Davidson Horsepower Chart
For a better comparison, we’ve compiled the performance figures of the production V-twin engines into this Harley-Davidson horsepower comparison chart.
Please note that this chart is for information purposes only since these engines have been produced with many different intake and exhaust configurations. What’s more, they saw many updates during their lifetimes, resulting in different HP ratings.
Harley-Davidson Engine HP Chart
| Engine | HP |
| F-Head (Twin) 50″ | 11 |
| Flathead 45″ | 22-30 |
| Flathead 74″ | 30-35 |
| Flathead 80″ | 35-40 |
| Flathead 54″ | 50-55 |
| Knucklehead 61″ | 37-40 |
| Knucklehead 74″ | 45-55 |
| Panhead 61″ | 50-55 |
| Panhead 74″ | 55-60 |
| Shovelhead 74″ | 60-65 |
| Shovelhead 80″ | 60-70 |
| Evolution 54″ | 45-55 |
| Evolution 67″ | 50-62 |
| Evolution 74″ | 58-66 |
| Evolution 80″ | 50-60 |
| Twin Cam 88″ | 55-62 |
| Twin Cam 96″ | 60-66 |
| Twin Cam 103″ | 68-75 |
| Twin Cam 110″ | 75-90 |
| Revolution 69″ | 115 |
| Revolution 76″ | 125 |
| Revolution VRSCSE² 76″ | 165 |
| Milwaukee-Eight 107″ | 91 |
| Milwaukee-Eight 114″ | 102 |
| Milwaukee-Eight 117″ | 105 |
| Milwaukee-Eight 131″ | 121 |
Disclaimer: These charts are for informational purposes only! For more information, please check the official factory manuals!
Harley-Davidson Model HP Chart
As a reference we’ve also compiled the HP ratings of some popular Harley-Davidson motorcycles into one list:
| Model | HP |
| 2021 Harley-Davidson Pan America 1250 | 145 |
| 2021 Harley-Davidson Bronx 975 | 115 |
| 2021 Harley-Davidson Electra Glide Standard | 92.5 |
| 2021 Harley-Davidson Road King | 92.5 |
| 2021 Harley-Davidson Iron 883 | 49 |
| 2020 Harley-Davidson Street 750 | 64 |
| 2021 Harley-Davidson Low rider S | 101 |
| 2021 Harley-Davidson Road Glide | 100 |
| 2021 Harley-Davidson Street Glide | 92.5 |
| 2021 Harley-Davidson Street Glide (special) | 100 |
| 2021 Harley-Davidson Forty-eight | 60 |
| 2021 Harley-Davidson Livewire (Electric) | 100 |
| 2021 Harley-Davidson Fat Bob 114 | 85 |
| 2021 Harley-Davidson Fat Boy 114 | 100.5 |
| 2021 Harley-Davidson Heritage Classic | 92 |
| 2021 Harley-Davidson Breakout 114 | 78 |
| 2021 Harley-Davidson Sports Glide | 92.5 |
| 2021 Harley-Davidson Iron 1200 | 60 |
| 2021 Harley-Davidson Sportster Iron 1200 | 67.7 |
| 2021 Harley-Davidson Roadster | 121 |
| 2021 Harley-Davidson Street Bob | 90 |
| 2021 Harley-Davidson Softail Slim | 74 |
| 2021 Harley-Davidson FXDR 114 | 90 |
| 1998 Harley-Davidson FXST Softail | 48 |
| 2014 Harley-Davidson Softail Deluxe | 78.5 |
| 2014 Harley-Davidson Street Glide Special | 76 |
| 2016 Harley-Davidson Softail Slim S | 82 |
| 2010 Harley-Davidson V-Rod Muscle | 123 |
| 2006 Harley-Davidson VRXSE Screamin’ Eagle V ROD DESTROYER | 170 |
| 1904 Harley-Davidson Model 1 | 4 |
| 1911 Harley-Davidson Model 7D | 6.5 |
| 1928 Harley-Davidson JDH | 29 |
| 1930 Harley-Davidson Model VL | 40 |
| 1935 Harley-Davidson VD | 40 |
| 1935 Harley-Davidson Model RL | 18.5 |
| 1937 Harley-Davidson EL Knucklehead 61 | 40 |
| 1942 Harley-Davidson WLA 45 | 25 |
| 1932 Harley-Davidson RL 45 | 18.5 |
| 1946 Harley-Davidson FL Knucklehead 74 | 53 |
Disclaimer: These charts are for informational purposes only! For more information, please check the official factory manuals!
Takeaways – FAQs About Harley HP Figures
As a takeaway, we’ve answered the most common questions about the performance of Harley-Davidson engines!
How Much HP Does a Harley 54” (883cc) Have?
The performance of Harley 54” (833cc) engines averaged from 45 up to 55 HP. These power sources were available in Flathead and Evolution configurations as well.
How Much HP does a Harley 74” (1200cc) Have?
Generally speaking, a 74 cubic inch (1200cc) Harley engine can produce anywhere from 30 up to nearly 70 HP.
The manufacturer offered 74” engines in five different configurations, which were as follows:
- H-D Flathead 74”: 30-35 HP
- H-D Knucklehead 74″: 45-55 HP
- H-D Panhead 74″: 55-60 HP
- H-D Shovelhead 74″: 60-65 HP
- H-D Evolution 74″: 58-66 HP
How Much HP Does a Harley 80” (1340cc) Have?
You can expect about 35-70 HP from an 80” (1340cc) Harley engine, depending on its configuration and features.
The ancient Flathead 80” engine produced about 35-40 HP while the more modern Shovelhead and Evolution 80” power mills cranked out about 50-70 HP.
How Much HP Does a Harley 88” (1450cc) Have?
Harley-Davidson’s Twin Cam 88” engine offered approx. 55-62 HP depending on the year and model. This power source debuted in 1999 and remained in the lineup through 2006.
How Much HP Does a Harley 96” (1580cc) Have?
The performance of a 96” (1580) Harley Twin Cam engine falls into the range of 60-65 HP.
How Much HP Does a Harley 103” (1600cc) Have?
The Harley-Davidson 103” (1600cc) Twin Cam engine produced about 68-75 HP at the rear wheel.
How Much HP does a Harley 107” (1750cc) Have?
The claimed horsepower of the Harley-Davidson Milwaukee-8 107” (1750) engine is 91 HP.
How much HP does a Harley 114” (1870cc) Have?
The claimed horsepower of the Harley-Davidson Milwaukee-8 114” (1870) engine is 102 HP.
How much HP does a Harley 117” (1920cc) have?
The claimed horsepower of the Harley-Davidson Milwaukee-8 117” (1920) engine is 105 HP.
How much HP does a Harley 131” (2150cc) have?
The claimed horsepower of the Harley-Davidson Milwaukee-8 131” (2150) engine is 121 HP.
Which Harley Engine Has the Most HP?
The most powerful Harley-Davidson engine ever built is arguably the VRSCSE² Screamin’ Eagle V-Rod rated at 165 HP.
This factory-modified 76” V-twin belonged to the Revolution engine family and came with many advanced features like fuel injection, liquid cooling, and dual overhead camshafts.
This power mill was planted in the drag-racer Harley-Davidson VRXSE Screamin’ Eagle Destroyer.
When it comes to the latest lineup, Milwaukee-8 131” is the most powerful engine option from Harley-Davidson.
This big-block Harley engine cranks out no less than 121 HP without any modifications.
References:
https://www.harley-davidson.com/
http://www.hbmcsf.com/325194280
https://www.thunderbike.com/harley-davidson-engines/
https://www.jpcycles.com/common-tread/moto-101/harley-engine-history
https://www.motorcyclistonline.com/brief-history-harley-davidsons-big-twin/
