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7 Cylinder Continental Dummy Engine Specs and Instructions
CONTINENTAL R-670-5 SCALE ENGINE FOR PT-17
ASSEMBLY INSTRUCTIONS
Parts required: (1) plastic crankcase, (7) Williams Bros. ¼ scale J-5 cylinders #72700
- Trim 1/16” from bottom of each cylinder half and then cement them together.
- Now trim 1/8” from top of base flange and then cement to cylinders making sure the notch in base flange aligns with seam in cylinder.
- Sand off the alignment lugs on the rocker box mounts on the cylinder head and sand mounts smooth.
- Assemble rocker boxes as per Williams’s bros. (WB) instruction drawing.
Do not glue to cylinder as shown! On the continental the push rods are in the rear.
- Glue rocker boxes to the cylinder head extending to the rear (the half that the intake tube mounts to.) making sure they are mounted perpendicular to the seam in the cylinder and are parallel to each other also the rocker box that is shown on WB drawing on left side facing forward should now be on right side facing rear and same for other side. This keeps the mounts for the push rod tubes in proper alignment.
- Glue push rod tubes to rocker boxes with bottom of tube in line with cylinder flange and with mounting lugs running front to rear.
- Assemble intake tube and trim 1/8” from the end that mounts on cylinder head, also sand the same end on a slight angle so that the tube angles toward the center of the cylinder(this gives clearance for push rod tube).
- Glue intake tube to round flange and to cylinder as shown on WB drawing.
- Glue exhaust flange to cylinder. Do not glue exhaust stack to cylinder at this time.
- Repeat the above steps on the other six cylinders
- Add sparkplugs and ignition tubing and you now have seven very accurate looking Continental cylinders.
- Cut the ABS crankcase from backing along 7 1/2” diameter flange.
- Mark and cut out (7) 1 1/4” holes for the cylinders. The center of the hole is located on the center of the cylinder boss and 7/8” back from front of boss.
- Test fit cylinders on crankcase and make any adjustments necessary. The flanges on the push rod tubes should sit on raised mounts at rear of crankcase.
- Glue the cylinders to the crankcase.
- The back of the crankcase flange can be reinforced with a ¾ “ wide ring of 1/8” lite ply. ¼” aircraft ply blocks are glued to the inside of the shroud where the holes for the mounting screws will be drilled. Use 4-40 socket head screws and ‘T’ nuts to mount the engine to the shroud.
- Now glue the exhaust stacks to the cylinders so they point to the front of the fuse shroud, this is the exhaust collector ring on full size PT-17.