| Engine | Twin Cam 110™ (1803cc) Screamin’ Eagle |
|---|---|
| Model Years | 2007 (FLHRSE3), 2008 (FLHRSE4) |
| Oil Specification | Screamin’ Eagle SYN3 20W50 (3.8 L) |
| Spark Plug | Harley-Davidson 6R12 |
| Battery | 66010-97D |
| Front Tire | 130/90B16 (’07) / 130/80B17 (’08) |
| Rear Tire | 170/60R17 |
Engineering Heritage: The Birth of the 110 Cubic Inch Powerhouse
A pivotal moment in Custom Vehicle Operations (CVO) history occurred in 2007 with the introduction of the FLHRSE3. This model marked the first time the Screamin’ Eagle Road King was equipped with the Twin Cam 110™ engine. Unlike previous iterations that utilized the 103 cubic inch platform, the 110 was designed to push the limits of factory-warrantied performance, delivering a staggering 115 ft-lb of torque at 3000 RPM. This engineering shift solidified the CVO line as the ultimate expression of Harley-Davidson’s touring performance.
Technical Performance & Architecture
The FLHRSE3 and FLHRSE4 are built upon the classic touring chassis but enhanced with premium components. The 1803cc V-Twin features electronic sequential port fuel injection (ESPFI) and is mated to a 6-speed Cruise Drive transmission. One critical technical distinction between the 2007 and 2008 models is the front wheel configuration: the 2007 model utilizes a 16-inch front wheel, whereas the 2008 model transitioned to a 17-inch wheel for improved handling stability and aesthetic presence.
Maintenance Guide & Service Requirements
To maintain the high-performance standards of the Screamin’ Eagle engine, strict adherence to fluid specifications is mandatory. At MotoSpecsLab, we emphasize the use of Screamin’ Eagle SYN3 20W50. This synthetic lubricant is specifically formulated to handle the increased heat generated by the 110 CUI air-cooled engine.
Key Service Intervals:
- Engine Oil: 3.8 Liters (4.0 Quarts) of SYN3 20W50. Check every 1,000 miles; change every 5,000 miles.
- Spark Plugs: Utilize Harley-Davidson 6R12. Proper gapping is essential to prevent high-load knock.
- Battery: The high-compression 110 requires significant cranking amps; always use the 66010-97D or equivalent high-CCA AGM battery.
- Tire Pressure: Critical for heavy touring loads. Maintain 36 psi (2.5 bar) in the front and 40 psi (2.8 bar) in the rear.
Expert Verdict: The Collector’s King
The FLHRSE3/4 remains one of the most desirable CVO models for enthusiasts who value the raw torque of the Twin Cam era. While the early 110 engines were known for running hot, proper maintenance and modern synthetic oils have proven these machines to be reliable long-distance cruisers. It represents the pinnacle of ‘factory custom’ before the transition to the Milwaukee-Eight platform.
Frequently Asked Questions
Q: Why did the tire size change in 2008?
A: Harley-Davidson updated the front wheel to 17 inches on the FLHRSE4 to accommodate larger rotors and provide a more modern steering feel compared to the 16-inch setup on the FLHRSE3.
Q: Can I use standard 20W50 conventional oil?
A: While possible, it is highly discouraged. The 110 CUI engine operates at higher thermal loads than standard Twin Cams; synthetic SYN3 is required to prevent premature breakdown of the lubricant.