41 J-3 Cub Dummy
Cylinders On Left Side of Fuselage
So all will know, I agree with your
recommendation on selecting the forward position for locating the dummy
cylinders on the fuselage and nose block.
I used the picture of a 65 hp Continental engine
on the front of a J-3 Cub to determine the fore and aft cylinder spacing. As
you can clearly see, basically there is no space between the cylinders.
After much trial positioning and screwing around,
I finally decided how and where I am going to install the dummy cylinders on
the left side. Since the left two cylinders are slightly ahead of the right
two cylinders, I located the front left cylinder as far forward as I
possibly could on the nose block as shown below. I used a spruce
strip inside the cylinder and let it protrude out an 1/8" in length. For
strength, I cut a square hole 1/8" deep in the nose block to receive the
spruce (stub) protruding out of the back of the cylinder as shown below.
This hole is located such that the rear face of the cylinder fins lines up
with the rear face of the nose block. Because the nose block is beginning
to round at this location, I glued an additional sheet balsa wafer on the
back of this cylinder. Once dry, I cut and sanded the wafer to conform to
nose block contour so it would seat flush with the nose block.
I plugged the hole for the rear cylinder and
repositioned it in such a way that the forward face of the cylinder fins
line up with the forward face of the fuselage. With the nose block flush
against the fuselage forward face, the two left dummy cylinders meet at the
separation line of the nose block and fuselage as shown below.
This shows the nose block partially pulled away
from the fuselage, taking the front left cylinder with it. The round hole in
the fuselage behind the cylinders is for the exhaust pipe. this will also
have to be plugged and moved forward when I make the exhaust manifold.
Recalling that the Continental's right two
cylinders are slightly behind the left two cylinders when the engine is
viewed from the top, some different approach will have to be used in
attaching the forward right cylinder to the fuselage because it is going to
overlap the separation line of the nose block and fuselage! :O< I have a
couple of ideas on how to do this, but I will have to work through this
first.................................Tandy