Designation	No.4
Bore	1 1/2 inch
Stroke	1 1/2 inch
Configuration	Vertical single cylinder
Height	10 inches
Extra equipment	Drain cocks Displacement lubricator Reversing gear
Taps required	2, 4, 5 BA 3/16 x 40 tpi 1/4 x 32 tpi 5/16, 3/8, 1/2 x 26 tpi
Notes	Usually seen with the standard 6-spoke flywheel, although engines fitted with the balanced disc flywheel are well-suited to direct-coupled generating duties, running well at high speed.