See Figure 3-6. A design feature is the Ricardo Comet V pre-combustion chamber which has a spherical chamber which mixes the air and fuel by air swirl. This assists in promoting high turbulence. This is an ante-or divided combustion chamber, having the major chamber in the cylinder head and only a small space between the piston and the cylinder head. Close piston clearance produces high turbulence in the ante chamber and promotes rapid combustion. The charge is forced out of the throat’area, agitating the entire mixture and resulting in more complete combustion. This design has a broad speed operating range. It also provides low noise and effective emission control. The pre-chamber is installed in the cylinder head flush to + .050mm (.002 in.).
See Figure 3-7. The 1982-1984 LH6 and LL4 prechamber was cast from nichol base (nimonic 80 alloy) stainless steel and is nonmagnetic and marked M, N, P. The late 1984 and 1985 LH6 pre-chamber is cast from iron base high carbon alloy and is magnetic and marked W, X, Y on the outer area.
The 1985 LL4 pre-chamber is a reversed throat type, with a different locating notch.
The pre-chamber is pressed into the cylinder head. Orientation is provided by a locating tab on the prechamber and a mating slot in the cylinder head. Figure 3-7 provides a detailed view of the pre-chamber.
