How to Restore Your Harley-Davidson 1937-1964

• 1937-1947 Harley-Davidson Knucklehead
• 1948-1964 Harley-Davidson Panhead
• 1937-1948 Harley-Davidson Big Twin Side-Valve
• 1937-1952 Harley-Davidson 45 Solo
• 1937-1963 Harley-Davidson Servi-Car

• Vehicle ID Numbers (VIN), motor and frame numbers
• How to restore the frame and bodywork
• How to restore the engine and transmission
• Correct paint colors and plating finish
• Electrical ignition and lighting components
• Accessories and options
• ...and much more!

This chapter is divided into three main topics: Motor Overview, Motor Parts Identification, and Motor Repair. Motor Overview describes the types of motors covered by the chapter and explains the principle operation of the Harley-Davidson V-Twin motor.

Motor Parts Identification describes the function of each part and the variations of each part. Motor Repair offers step-by-step instructions and tips for a total overhaul of the motor.

Motor restoration consists of two tasks. One, the complete and proper overhaul of the motor and, two, the correct detailing of the motor. In reality, these two tasks must be done simultaneously but for the flow of writing, they are discussed below as separate topics: Motor Parts Identification and Motor Repair.


MOTOR OVERVIEW

Four types of motors are covered in this book:

• 1937-1973 45 Servi-Car and Solo motors



• 1937-1948 74 and 80 Big Twin side-valve motors



• 1937-1947 61 and 74 Knucklehead overhead-valve motors



• 1948-1965 61 and 74 Panhead overhead-valve motors

Harley-Davidson motors up through the early 1980s are mounted into the frame by four bolts at the bottom and a bracket at the top. They are two-cylinder motors with the cylinders set 45° apart, in-line, front to back, in a V shape – hence the name V-Twin.

Some have their valves over the pistons and are called overhead-valve (OHV) motors; some have L or Ricardo heads with the valves alongside the cylinder and are called side-valves (SV) or Flatheads.

The 1936-1947 61 and 74 Knucklehead motors and the 1948-1965 61 and 74 Panhead motors are all overhead-valves motors. The 1937-1973 45 motors are side-valve motors like the 1937-1948 74 and 80 side-valve motors, also called Flathead.


MOTOR REPAIR

Boiled down to the basics, all 1937-1964 V-twin Harley-Davidson motors are the same. They all have two cylinders set 45° apart, two removable heads, two inlet valves, two exhaust valves, two cam ground pistons, a built up crank assembly (consisting of male and female piston connecting rods, left and right flywheels, crank pin, and mainshafts), a gear case with a cam(s), a gear driven timer, a feed oil pump, a return oil pump, and split crankcases.

The size and shape of these components do vary from model to model but their relative position on the motor is usually the same which allows for similar instructions for disassembly and assembly.

The only radically different construction between the motors occurs in two areas: the valve configuration and the oil pump(s) layout. The dividing characteristics in both cases is the division of the motors into side valve type motors and overhead valve type motors.

In the first area, the overhead valve motor valves are assembled into the head and are actuated by a series of peripheral parts. The side valve motor valves are assembled into the cylinders and are run directly off the valve tappets.

In the second area, while all motors have feed and return oil pumps, the overhead valve motor feed and oil pumps are built into one body. The side valve motor feed and oil pumps are housed in two separate bodies.

Since the similarities outweigh the differences, the disassembly, repair, and assembly instructions for all the motors covered here are combined into one set of instructions. Difference between the models will be discussed as they arise in the procedure.

The only other difference which needs to be mentioned at this time deals with tolerances and torque settings. These can vary greatly from one model to another. Tolerances (running fit, clearance, etc.) and torque readings will be mentioned at the needed points. These are also listed in the Appendix under each models specifications.

• Where to Begin
• Chassis Restoration
• Wheels and Brakes
• Motor Restoration
• Fuel System Restoration
• Transmission and Clutch
• Harley-Davidson 6-Volt Electrical System
• Accessories and Options
• Harley-Davidson Paints
• Engine Specifications
• Model Specifications and Detials
• Index