Advantages Of The Rotary Valve Engine - BOMBARDIER 1996 Ski-doo MX Z440 Handbook

Section ENGINE PREPARATION
04
, F01D6XS
1. Pinion (onrotaryvalve shaft)
2. Rotary valve
3. Gear(crankshaft)
4. Gear(on rotary valve shaft)
Effect on power curve of changing rotary valve closing angle.

ADVANTAGES OF THE ROTARY VALVE ENGINE

The major differences between a piston port engine and a rotary valve engine are :
1 ) Intake port directly positioned in the crankcase.
2) The opening and closing of the intake port is controlled by a rotary valve disc instead of the
piston.
04-32
2
1
90
Early closing
80
70
60
/
/
50
/
/
40
/
I I I
I
5000 6000 7000
0
Late closing
-
700.
1 1
1 1 I
8000 9000
85°
I