Model Airways CURTISS JN-4D JENNY Instruction Manual page 27

one or more of the pipes or manifolds to
hold the alignment, then glue the four
cylinders at once. Anyway you choose will
be acceptable. The important issue is that
all these parts fit together properly. Adjust-
ments would be difficult with a cylinder out
of alignment.
Installing the intake manifolds and
manifold piping (Figure 5-8):
intake manifolds must be installed before
the cylinder rocker arms and actuating
spring and housing, so follow the assembly
sequence below.
On top of each side of the V intake mani-
fold, install the intake manifold pipes
(E40). Between E40 and the manifold,
there is a long section (E41A) on the right
side and a short section (E41B) on the left
side). Glue the intake manifolds (E42) in
the holes on the cylinders, and glue the
piping on the underside of the manifolds.
Note that there are no holes or pins in the
piping or intake manifolds so that you can
file the ends for fine adjustment if neces-
sary. Gluing the piping should suffice.
However, you can drill holes in the piping
and manifolds and insert pins if you want
more secure connections. This is shown
on the plans as an option.
Installing the water inlet piping (Figure
5-9):
Install the water inlet pipes (E31) in the
lower outboard holes on the side of the cylin-
ders. Then install the long right (E32) and
short left (E33) curved sections of the pipes
between the side pipes and the water pump.
To join, use short pieces of PVC flex tubing.
The flexible tubing mentioned for the
Note:
engine piping connections supplied is clear
tubing. The tubing should be black or possi-
bly a dull red color, so paint the tubing with
matte acrylic paint.
There is a pipe from the underside of
Note:
the water pump to the radiator and tubes
from the water pump to the water jacketed
V intake manifold, but don't install these at
this time. The engine must be mounted in
the fuselage first. These pipes or tubing
will be discussed in later paragraphs.
Installing the water outlet pipes (Figure
5-10):
Glue the water outlet pipes (E26B)
to the outsides of the rocker support atop
each cylinder. Make sure they are correctly
located fore and aft, since there are no
alignment pins for the installation. On the
real engine, the water exits the cylinders
via the center support then into the side
pipes. The front of the pipes will have a flex
tube connecting the pipe to the radiator,
but this will be installed after the engine is
installed. From the back of each pipe, run
a copper wire (fake tubing) from the pipe
down to the top holes drilled in the sides of
the V intake manifold. Drill a hole in the
end of E26B for the wire.
Installing the intake rocker actuating
spring and housing, and rocker arms
(Figure 5-11):
This is probably the most
difficult effort in building the engine, so take
The
Note:
INLET PIPE
E31
(BOTH SIDES)
FRONT LEFT CYLINDER
FLEX TUBE TO RADIATOR (INSTALL LATER)
FIG. 5-11 ACTUATING SPRING / HOUSING & ROCKER ARMS
ASSEMBLED
your time. Make sure all the castings are
clean and fit correctly. Note that the valve
springs are cast as a part of the rocker arms.
If you so desire, you can cut these off and
substitute a real spring or coiled wire.
Remember, the intake manifolds must be
installed before you start the rocker arm
installation.
First, install the intake rocker actuating
spring and housings (E27) into the holes
above the cylinder holes on the block. Make
sure the long side of the fork at the top is in
line with the engine block. Glue the intake
rocker arm on the support on top of the
cylinders and the outer end in the fork on
the actuating spring rod, and also glue the
FIG. 5-9 WATER INLET PIPING
HOLE NEAR BOTTOM
OF CYLINDERS
FLEX TUBING
E33 SHORT (LEFT SIDE)
FIG. 5-10 WATER OUTLET PIPING
INTAKE VALVE ROCKER
WATER OUTLET
E2 (SPRING SHOWN
PIPE
DOTTED UNDER PART)
INTAKE ROCKER
ACTUATING SPRING
AND HOUSING E27
E27 FITS HOLE
IN BLOCK
27
E32 LONG
(RIGHT SIDE)
WATER PUMP
DRILL HOLE FOR WIRE
OUTLET PIPE E26B
(BOTH SIDES OF
ENGINE)
FLAT FACES INBOARD –
GLUE TO ROCKER SUPPORTS
ON EACH CYLINDER
ROCKER ARM
SUPPORT – PART
OF CAST CYLINDER
WATER PIPES AND
MANIFOLDS OMITTED
HERE FOR CLARITY
SPARK PLUG
(FRONT ON RIGHT
CYLINDERS, REAR ON
LEFT CYLINDERS)
bottom of the rocker arm spring to the top
of the cylinder.
Glue the exhaust rocker arm in place. The
spring at one end glues to the top of the
cylinder. The center glues to the support on
top of the cylinder. The short pin on the
other end glues into the recessed hole on
the top of the intake rocker arm. On the
real engine, this pin is actually a rod that
goes through the actuating spring tube into
the engine. Careful – don't use too much
glue on these fittings and obscure detail.
Installing the exhaust manifolds (Figure
5-12)
: Glue the exhaust manifolds (E43)
into the holes in the cylinders. Note there
is a pin on both the top and bottom sides
.015"-DIA.
COPPER WIRE
(FAKE TUBE)
TO TOP HOLE
IN SIDE OF
V INTAKE
MANIFOLD
(SEE FIG. 5-19)
EXHAUST
VALVE
ROCKER
E29