Honda VF and VFR - V4 Engine

V4 Engine

The V-Four engine was prominent in Honda's model line-up in the early 1980s with engine capacities ranging from 400 cc to 1,000 cc. The V-Four design had only been used a few times in the history of motorcycles, most notably by Matchless. The V4 cylinder arrangement achieves perfect primary balance giving a smooth and nearly vibration-free operation. Primary balance of the engine requires fewer balance shafts cutting down on weight and internal friction. The V4 engine is often described as a balance between the low end torque available in V-Twin engines with the high end power available in Inline-four engines.

The earliest Honda VF series engine was designated the V45 for its size (45 cubic inches / 740 cubic centimetres) and was very narrow being only 16 inches (406 mm) wide. A smaller V30 (500 cc) engine and a larger V65 (1,100 cc) engine were later available. Since the mid 1990s engine displacement has grown with each successive model from 750, to 800, to 1200 cubic centimeters.

In 1982, the first year of the VF models 'first gen', reliability and quality control problems occurred due to new automated production equipment at Honda's plant in Hamamatsu, Japan. Regardless, Honda sold out its first year's inventory of Sabres and the Magnas were not far behind. 1983 saw the engine revised to correct the problems from the previous production year and the introduction of the V65 and the Interceptor. Cam-wear problems surfaced during 1984 in the larger displacement bikes, which, by the time it was corrected, led to eight factory cam revisions over the course of just one year.

The chain-driven valvetrain was dropped from the VFR, with the 1986 'Second Generation' VFR750, in favor of gear driven camshafts to help distance the VFR from the reputation of the earlier VF engine faulty cam-chain tensioners. The new system allowed the tensioner to reach maximum travel while the chain remained within service limits. The sixth generation VFR800 returned to chain driven cam-chains along with the introduction of variable valve timing. The seventh generation VFR1200 has since replaced the original VTEC variable valve timing system with the unicam system originally developed for the CRF450R dirt bike.