Top Flite Q7903 INSTRUCTION BOOK

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 Giant F4U Corsair, this 1/5th scale
Radial will fit any cowls with a frontal opening of 8" to 9-1/4". 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.

1/5 SCALE

PARTS LIST

❏ (1) ABS Plastic Radial RADIAL05
❏ (6) 8" Plastic Push Rod Tubes PLTB025
❏ (1) 16" Wire for Ignition Leads WIRES58
❏ (1) Instruction Sheet RADIALP05

ASSEMBLY

The following procedure covers the assembly and modifications
required for a flying model. No modification is required for static display
models.

❏ 1. Trace or photocopy the Baffle Template from your plans onto a 10"

x 10" sheet of 1/8" lite-ply (not included). Cut around the circumference
and the engine opening with a scroll or coping saw.

❏ 2. Trim the Radial to fit the lite-ply baffle with a hobby knife

or scissors.

TOOLS AND SUPPLIES REQUIRED

❏ 1/8" x 10" x 10" Lite Ply ❏ 6-Minute Epoxy
❏ Hobby Knife with # 11 Blade ❏ Small Paint Brushes
❏ 1/16" and 1/8" Drill Bits ❏ Scroll or Coping Saw
❏ Paint (see painting instructions) ❏ #100 & 240-grit Sandpaper
❏ Round File or 1/2" Drum Sander
❏ Hand Drill or Dremel

®

MultiPro

❏ Rubber Cement or Spray Adhesive
❏ CA - Medium

❏ 4. Tape the Radial to the baffle, then test fit the assembly inside the

cowl. If necessary, sand the baffle and Radial for a good fit.

❏ 5. (Flight Modification) Trim away one or more of the plastic cylinders

to allow air flow across the “real” engine head.

❏ 6. Drill a 1/8" hole through each of the raised 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.

❏ 3. Cut away the prop shaft opening from the center of the Radial.

Smooth the edges with a round file or drum sander.

❏ 7. Use #240-grit sandpaper to lightly sand the full length of the 6

plastic tubes for better glue and paint adhesion. Cut 18 pieces 2-1/2"
long to use for the push rod tubes.

❏ 8. Sand the 16" wire, then cut 1-3/4" long pieces to use for the

ignition leads. Make a 90° bend 3/8" from one end.

Copyright © 2012 PRINTED IN USA RADIALP05

Note: As you will probably be removing at least one cylinder when you
use the Radial as an air baffle, you need not install push rods and an
ignition lead in at least 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 9 when you are ready to
proceed.

❏ 9. Insert the push pod 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.

❏ 14. Tape the Radial assembly inside the cowl. Make final adjustments

to the fit between the cutouts and the engine. By working from the
inside it’s possible to remove material from the Radial without affecting
the push rods tubes and ignition leads. Pay special attention to
unrestricted throttle movement.

❏ 15. When satisfied with the fit, smooth all rough edges with fine

sandpaper then paint the Radial.

❏ 16. After the Radial is painted and fuelproofed, glue the assembly in

the cowl with a mixture of 30-minute epoxy and milled fiber glass or
microballoons. Be sure to roughen the inside of the cowl with coarse
sandpaper. Apply a solid bead of this mixture around the entire
perimeter of the baffle for a secure bond.

❏ 10. Insert the ignition leads into the cylinders. NOTE: Bend the

ignition leads over the top of each cylinder so that they touch the
backing. The ignition leads will be installed in the baffle later.

❏ 11. Turn the Radial over and apply a drop of CA to both ends of all

pushrods and ignition leads.

❏ 12. 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 coarse sandpaper for a
better bond.

❏ 13. Drill a 1/16" hole through the Radial and ply backing at each

ignition lead location. Insert the ignition leads into holes you drilled and
apply a drop of thin CA to secure them in position.

PAINTING SUGGESTIONS

We painted our prototype Radial with Testors® Model Enamel paint then
sprayed two very light top-coats of fuelproof Flat Clear over the finished
job.

If you are building a scale replica of a particular aircraft, paint the Radial
in similar colors to the full scale version. The colors we chose represent
typical P&W colors with chrome plated push rod tubes.

PAINTING SEQUENCE AND COLORS USED

2. Crankcase - Gun Ship Gray

3. Cylinders - Euro Gray

4. Background - Flat Black

5. Push Rod Tubes - Silver

6. Ignition Leads - Red

7. Rocker Arm Covers - Black

8. Spark Plug Connectors - Gold or Copper

9. Cylinder Fins and weathering - Silver & black
Random fine lines on the fins

10. Engine I.D. Plate - Black with Silver details

11. Flat Finish Fuelproof Clear Coat - 2 VERY light coats

Questions or comments?

Top Flite Models

3002 N. Apollo Dr., Suite 1

Champaign, IL 61822

[phone]

www.top-flite.com