The Specifications Of A 2006 Tc88 Engine

The Twin Cam 88 is known for its large, V-Twin engine design.

The TC88 engine is a Harley-Davidson motorcycle engine, more prominently referred to as the Twin Cam 88. The engine used a twin cam fuel system to enhance burning and performance efficiency. Because of its large displacement, the engine was used with Harley-Davidson’s bigger cruiser and touring models, such as the Dyna series. A larger Twin Cam 88B was also released. This modified version had an increased displacement of 96 cubic inches, or 1,584 cc.

Engine Specifications

The 2006 Twin Cam 88 engine used a four-stroke, 45-degree, V-Twin design and had a piston displacement of 1,442 cc. The engine derived its name from the fact that it had one cam per cylinder. Each cam also had two lobes, which helped balance and align the engine during operation. Harley-Davidson did not release a power rating for the engine, but, according to the NightRider website, an estimated power rating placed the output approximately between 70 and 80 horsepower. The torque rating was an impressive 85 foot-pounds at 3,000 rpm. The pistons had an 8.9-to-1 compression ratio and a bore by stroke of 3.8 by 4 inches. The engine valves were pushrod operated and the overhead valves used hydraulic, self-adjusting lifters. The engine featured two valves per cylinder, totaling four valves.

Features and Equipment

Harley-Davidson designed the engine with an air-cooled cooling system and a six-speed transmission. The transmission was belt operated and the clutch utilized a multi-plate with a diaphragm spring in an oil bath. The starter was electrically operated. The fuel system used an Electronic Sequential Port Fuel Injection and the fuel control used a dual overhead camshaft. Approximate fuel consumption was 47 mpg, and, with some models, Harley-Davidson paired a 4.8-gallon tank with the engine. The transmission had the following gear ratios: first gear: 3.337-to-1, second: 2.313-to-1, third: 1.718-to-1, fourth: 1.391-to-1, fifth: 1.175-to-1 and sixth: 1-to-1.


The Twin Cam 88 engine followed in the footsteps of a long heritage of V-Twin Harley-Davidson engines. Harley-Davidson’s first 45-degree, V-Twin engine was released in 1909 and production only lasted two years. Released in 1911 was the F-Head, which improved on the original design of the 1909 engine. The F-Head was produced until 1929. The Flathead engine was produced, according to Harley-Davidson, for a remarkable 44 years, which set a record for years in production. The Knucklehead and Panhead began to display the large, V-Twin design characteristics of today’s Harley-Davidson engines. The Shovelhead was manufactured between 1966 and 1983. In the early 1980s, Harley-Davidson had a difficult time competing in the global motorcycle industry, but with the release of the Evolution engine, one of the company’s most famous, outlook began to change. That engine was produced for 15 years until 1999. The Twin Cam 88 was produced from 1999 until 2006; Harley Davidson now manufactures a Twin Cam 96 which is similar to the Twin Cam 88.