Engine Description
Teledyne Continental Motors, Inc.
TM
The camshaft gear (Figure 2-7) has 16 holes drilled in the outer track and one hole drilled in the
inner track. The speed pulse generated by the 16 hole-outer track is the Ne Pulse and the Nc
pulse is generated by the lone hole in top dead center inner track for Cylinder 1. As the camshaft
gear rotates, the holes in the gear are detected by the Speed Sensor Assembly (SSA).
The SSA consists of two pairs of sensors which detect steel density changes that occur when the
drilled holes in the camshaft gear pass by the sensor array. Detection of the open holes is sent as
a cam pulse signal to the FADEC Electronic Control Units (ECUs). The ECUs determine the
engine speed based on input from the SSA sensors signals which detect the speed pulses from the
camshaft gear outer track (Ne pulse) and the inner track (Nc pulse).
16 Ne Pulses
1 Nc Pulse
Figure 2-7.
Camshaft Gear
2-2.3. Accessory Case
The aluminum alloy casting of the accessory case is attached to the rear of the engine
crankcase, aligned with crankcase dowels; the accessory case is secured to the crankcase
by crankcase studs and various attaching hardware. Accessory mount pads on the rear
surface are machined in one plane parallel to the machined parting flange which
surrounds the front side of the casting. Mounting pads for the magnetos, alternator cover,
starter, tachometer drive, oil filter adapter, oil pressure relief valve and an oil suction
screen boss are provided. The accessory case casting has two holes above and three studs
to attach the starter and starter adapter. A mounting pad is provided for an oil screen
housing in lieu of the screw-on type oil filter.
The oil pump housing is machined into the internal portion of the accessory case. A
machined, threaded boss is located on the lower right side of the accessory case for
installation of a non-adjustable oil pressure relief valve. Oil pump gear chambers are
machined in the interior of the accessory case. The oil pump drive gear shaft hole is
machined in-line with the camshaft and the driven gear shaft hole is directly above it.
2-8
IOF-240 Series Engine Maintenance Manual
Change 1
31 August 2007