Top Flite TOPQ7901 User Manual

Dummy radial engine, Assembl y and finishing instr uctions

DUMMY RADIAL

ENGINE

ASSEMBL

Y AND FINISHING

INSTR

UCTIONS

The Top Flite

Dummy Radial Engine (hereafter

referred to as

Radial

) is patterned after the Pratt &

Whitney radial engines that powered numerous air-

craft from the

Golden Age

of aviation. Modeled to

fit the Top Flite F4U Corsair and AT-6 Texan, this

1/7th scale Radial will fit any cowls with a frontal

opening of 6-1/2" to 7". 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

Hand Drill or Dremel

Moto-Tool

1/16" and 1/8" Drill Bits

CA - Medium (Great Planes

Pro

™

recommended)

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

ASSEMBLY

The following procedure covers the assembly and modifi-

cations required for a

flying

model.

Static display models

require no modification.

❑

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 Corsair and AT-6 is the innermost circle.

❑

3.
Score

around the

inside

corner of the

Radial

with a

hobby knife.

Flex

the plastic around the rim until it breaks off.

❑

4. Cut away the prop shaft opening from the center of

the Radial. Smooth the edges with a round file or

drum sander.

❑

5.
Tape

the Radial to the ply baffle, then test fit the

assembly inside the cowl. If necessary, sand the ply baffle

for a better fit. The forward edge of the Crankcase should

be flush with the outside forward edge of the cowl.

❑

6. 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 and also

into the Ignition Harness Ring

between the Push

Rod holes.

❑

7. Use 240 grit sandpaper to lightly sand the full length

of the

3 plastic tubes

for better glue and paint adhesion.

Cut

18 pieces 1-1/4"

long to use for the Push Rod Tubes.

❑

8. 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. Randomly bend the

long

section to

simulate flexible wires.

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 Rod Tubes and an Ignition Lead in

one

Cylinder. Complete all 9 cylinders if you will

only

using the Radial for static display.

Painting Hint:

Most 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 Rod 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.

❑

10. Insert the Ignition Leads into the Crankcase and

the Cylinders.

❑

11. Turn the Radial over and apply a drop of CA to

both ends of all Push Rod Tubes and Ignition Leads.

(From the inside)

❑

12.

(Flight Modification)

Trim away one of the

Cylinders but leave excess backing material in place.

This material will be trimmed off during final fitting to

the engine.

❑

13. Glue the Radial to the ply baffle with CA. 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 glue bond.

1/16" Holes

Crankcase

Rocker Arm Cover

1/8" Holes

Top Flite Models

3002 N. Apollo, Suite 1

Champaign, IL 61822

(217) 398-8970

[email protected]

RADIALP1

❑

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.