| Motorcycle engine design and innovation has long | | | | design.Finally, five valves per jug was found to be the |
| surpassed that of the automotive industry, and industry | | | | right combination. This design gives the engine extra |
| observers agree that the big companies like Yamaha, | | | | intake valve perimeter, which allows it to flow more air |
| Honda and Suzuki can muster considerable R&D | | | | at low-to-medium valve lifts -- exactly where valves in |
| prowess here, which can then be applied to their | | | | most production automotive engines spend most of |
| automobile engines.Competitors are especially aware | | | | their operating time.Honda of America Mfg., Inc., has |
| of this. Says former Oldsmobile chief engineer Ted | | | | combined plant and production engineering with |
| Louckes: "That's where the leading edge of piston | | | | advanced manufacturing techniques to become one |
| engine technology is today. It's not in automobiles; it's | | | | of the leading engine producers in North America.The |
| not in aircraft. It's in motorcycles."The Goal: Better | | | | million-square-foot plant manufactures 500,000 high |
| CombustionWhen considering the advantages of a | | | | technology engines and drive trains a year. Kinzer |
| combustion chamber crammed with more than four | | | | noted that the plant produces everything that makes a |
| valves-per-cylinder, the first inclination is to think, aha! | | | | car "go and stop." He said that even Japan has no |
| Flow area! Five valves equals more flow area! True, to | | | | Honda facility comparable to the Anna plant. Its |
| a degree, but that's only part of the Yamaha's design | | | | production, he reported, equals the total of seven |
| strength.In the reigning days of the two-valvers, engine | | | | similar Honda manufacturing units in Japan. At present |
| designers would control pinging by incorporating squish | | | | production levels, a Civic or Accord engine is produced |
| bands into the combustion chambers. By the 1960s, the | | | | at the Anna plant every 27 seconds.Honda's iron |
| four-valve heads of Cosworth and Honda racing | | | | foundry operates three shifts per day. The ferrous |
| engines were allowing narrow included valve angles | | | | casting and machining operations include the production |
| and thus shallow combustion chambers. Put the spark | | | | of engine cylinder sleeves and brake discs and drums. |
| plug in the center, and voila!, good combustion.Yamaha | | | | Aluminum casting operations include high pressure |
| looked beyond four valves to unlock even better | | | | casting of engine blocks and transmission and torque |
| combustion. In the early '80s (Yamaha had only been a | | | | converter cases, low pressure casting of engine |
| serious producer of four-stroke engines for about ten | | | | cylinder heads and gravity casting of pistons.Joe loves |
| years!) it experimented with a variety of head and | | | | his motorcycle but he knows how to drive it safely. |
| valve configurations, even trying a | | | | Learn more at his blog here: Motorcycle Batteries and |
| seven-valve-per-cylinder (four intakes, three exhaust) | | | | More. |