Service notebook of Harold Gordon Cornell - 1917 - Part 7

Engines:- 110 H.p. Clerget

and to evenly distribute lubrication on the cylinder walls

which comes through holes drilled immediately below

the last groove on the piston skirt.

Gudgeon Pins are of case-hardened steel & are parallel

being made solid; they are secured by a set screw

passing through a hole in the lug, & screwing into the

gudgeon pin, set screw being secured by a split steel

ring passing through a hole in the head, & clamping

around the lug.

Crank Case is a drop steel forging, and is made in

two halves, cylinders being clamped between, & the

halves secured by a bolt passing between each cylinder

into which fits the collar turned on the cylinder

this preventing the cylinders being blown off, cylinders

being prevented from turning by a small key, between

cylinder & crank case. Crank case is supported by

being bolted at the back to the thrust box & at the

front to the gear box, which in turn are supported on the

shaft by ball bearings.

Engines:-  110 H.P. Clerget

Cylinders are of Ch Ni Steel, turned from a forging; thickness

of cylinder walls 3mm. A collar is turned on the skirt

which fits into a recess, turned in the crank-case, this

preventing the cylinder from being blown off; they are

prevented from turning by a small key, fitting between

crank-case & cylinder. Fins are turned for cooling &

strengthening purposes & two holes are drilled in the

head to accommodate the valves, the seatings of these

being screwed into the cylinder. Two brackets are

also screwed in to carry the ricker arms which operate

the valves. Provision is made for 2 sparking plugs, one

at the leading edge & one at the rear (Later engines both plugs

in front). Cylinders must be kept bright & clean to

enable internal defects to be discovered from the

outside.

Thrust Box is situated on the rear of engine rotates on the 

long end of shaft & is supported by two ball bearings

one being radiant and one self-aligning. It carries the

spare wheel, which is used to drive the auxiliaries, viz.

oil pumps, air pumps & magnets, & also the distributor ring

Hand drawn diagram - see original document

Engines:-  110 H.P. Clerget

which is used to collect current from a stationary carbon

brush & convey it by means of a wire to the plug

Between the two ball bearings is fitted a double-active,

thrust race, which is designed to take thrust, both

in tractor & pusher directions.

Tractor Thrust is first taken on a solid collar turned in

the thrust box, through the outer ball race, to the outer

ball cage, then to the central ball race, on to the

distance price, through the s.a. ball bearing to the crank

web.

Pusher Thrust is just taken on a screwed collar, screwed into the

thrust box through the inner ball race to the inner ball cage,

then to the central ball race, distant price radial bear bearing

& is finally taken by a locking nut screwed in the shaft.

Hand drawn diagram - see original document

110 H.P. Clerget

Valve Cleaning & Timing

Valves are mechanically operated by a system of

gears maintained in a gear box which rotates on

small end of shaft. In the centre of the gear-box

is placed a ball bearing which supports it on the shaft.

18 holes ate drilled around the gear box these being

bushed with phosphor bronze, for the guides for the

tappets. Keyed into the gear box are two internally

toothed rings which are used to drive the inlet &

exhaust cam wheels. They have 18 teeth & run

concentric with the crank shaft. On the eccentric

shaft are placed two externally toothed wheels which

have 16 teeth & run eccentric to the shaft : only

meshing with the gear ring at one point. On each 

fourth tooth of the gear which is an extension or cam

& this wheel gains two teeth for every revolution of the

engine. On one revolution an extension comes on

alignment with the tappet & pushes open the valve

but on the next revolution the wheel having gained two

teeth the tappet drops into the recess behind & the valve

Hand drawn diagram - see original document

110 H.P. Clerget

is not opened. On the 3rd revolution, two more teeth

having then gained the next extension comes in

alignment & the valve is opened. By this means

the valve is opened once every two revs.

Method of timing for the Valves

Place No 1 Cylinder at top dead centre & secure

the engine; this will bring No. 7 & No 4 cylinders

in the correct position for timing viz No 7 for the

inlet valve ay 110⁰ after T.D.C. & No. 4 for the exhaust

valve at 58⁰ past B.D.C.

To Time Inlet Valve Turn the externally toothed which

until an extension comes immediately underneath no 7 tappet

Place in the internally toothed ring the position of this

being governed by a key; the inlet valve will be then

timed. Proceed to time the exhaust valve without

shifting engine by the same method but getting the extension

underneath No 4.

Position for timing

Hand drawn diagram - see original document

-110 H.P. Clerget -

Nosepiece:- is locked to the front of gear box &

carries the propellor; it is made hollow &

the prop is secured to it by means of a steel box

sliding up on the tapered portion of the nose-piece

being prevented from turning by a key & keyway,

& firmly secured at the front by a locking nut;

the nut is secured by a split steel ring.

Lubrication: is delivered under pressure obtained by

an oil pump driven off the spare wheel, oil coming

from the tank to the pump by gravity; it enters

the engine through a union placed in the central

support; this union registers with a hole in the tapir

part of the crankshaft. A copper pipe is fixed in this hole

& conveys the oil through the hollow crankshaft

to the crank web. Up through a drilled hole in the

crank web to the crank pin but delivering by a branch 

hole at the back of the web, a supply of oil for the thrust

box. Holes are drilled on the crank pin through which

the lubrication for the big-ends passes. The remainder runs

along the crank pin & down the other web, coming out

Hand drawn diagram - see original document