Top Flite TOPQ7902 User Manual
1/8 scale replica radial engine, Assembly and finishing instructions, Assembly
1/8 SCALE
REPLICA RADIAL
ENGINE
ASSEMBLY AND FINISHING
INSTRUCTIONS
The Top Flite Replica Radial Engine (hereafter
referred to as Radial ) is patterned after the Pratt &
Whitney radial engines that powered numerous
aircraft from the Golden Age of aviation. Modeled
to fit the Top Flite P-47D Thunderbolt, this 1/8th
scale Radial will fit any cowls with a frontal opening
of 5-1/2" to 6-1/4". Not only does the Radial
enhance scale appearance, but it also serves as
an air-flow baffle for more efficient engine cooling.
WARNING
Do not attempt to start your engine unless the
radial has been modified to permit cooling airflow
to the engine! See text for more information.
TOOLS AND SUPPLIES NEEDED (Not Included)
Hobby Knife with # 11 Blade (HCAR0100)
Hand Drill or Dremel
®
Moto-Tool
®
1/16" and 1/8" Drill Bits
6-Minute Epoxy (Great Planes
®
Pro
™
, GPMR6042)
CA+ (Great Planes
®
Pro
™
, GPMR6014)
1/8" x 8" x 8" Lite-ply
Round File or 1/2" Drum Sander
Small Paint Brushes
Paint (see painting instructions)
Scroll or Coping Saw
Rubber Cement or Spray Adhesive
100 & 240-Grit Sandpaper
The following procedure covers the assembly and
modifications required for a flying model. Static display
models require no modification.
❑
3. Trim the Radial to fit the lite-ply Baffle with a hobby
knife or scissors.
❑
5. Tape the Radial to the baffle, then test fit the
assembly inside the cowl. If necessary, sand the baffle
and Radial for a better fit.
❑
7. Drill a 1/8" hole through each of the indented marks
around the perimeter of the crankcase and also through
the bottom of each rocker arm cover. Drill a 1/16" hole
through the dimple near the top of each cylinder.
❑
8. Use 240-grit sandpaper to lightly sand the full length
of the 5 plastic tubes for better glue and paint adhesion.
Cut 18 pieces 2" long to use for the pushrod tubes.
❑
9. Sand the 16" wire, then cut 9 pieces 1-1/2" long to
use for the ignition leads. Make a 90 degree bend 3/8"
from one end.
Note: As you will probably be removing at least one
cylinder when you use the Radial as an air baffle, you
need not install pushrod tubes and an ignition lead in
one cylinder. Complete all 9 cylinders if you will only be
using the Radial for static display.
Painting Hint: Some modelers find that it’s easier to
paint this type of structure before final assembly. If this is
your preference, skip down to the section on Painting.
Then return to step 10 when you are ready to proceed.
❑
10. Insert the pushrod tubes into the rocker arm
covers and the crankcase as shown in the photo. They
should protrude inside the Radial about 3/32" at each
end of each piece. Don't worry about gluing them yet.
❑
12. Turn the Radial over and apply a drop of CA to
both ends of all push rod tubes and ignition leads.
❑
13. Glue the Radial to the ply baffle with 6-minute
epoxy. Be sure to align the “removed cylinder” with the
opening in the baffle. Hint: Roughen the back surface of
the Radial with 100-grit sandpaper for a better bond.
Top Flite Product Support:
3002 N Apollo Drive Suite 1
Champaign, IL 61822
Telephone: (217) 398-8970
Fax: (217) 398-7721
E-mail: airsupport@top-fl ite.com
© Copyright 2008
RADIALP08 v1.1
❑
2. Trace or photocopy the Baffle Template, then glue
the copy to a sheet of 1/8" lite-ply (not included). Cut
around the circumference and the engine opening with a
scroll or coping saw.
❑
11. Insert the ignition leads into the cylinders.
NOTE: Bend the wires over the top of each cylinder so
that they touch the backing. They will be installed in the
baffle later.
❑
4. Cut away the prop shaft opening from the center of
the Radial. Smooth the edges with a round file or
drum sander.
❑
6. Flight Modification — Trim away one of the
cylinders but leave excess backing material in place. This
material will be trimmed off during final fitting of
the engine.
❑
1. Measure the inside diameter of your cowl about
1-1/2" from the frontal opening and match this size to the
concentric circles on the Baffle Template. The correct size
for the Top Flite P-47 is the innermost solid line on
the template.
ASSEMBLY