Performance impact of upgrading HO engine motor overall process

Everywhere you look you see discussions about upgrading an engines motor to this or that improved or recent choice. This is usually associated with a video and a claim that the engine runs much smoother. This always leaves me cold. The upgrade can easily cost $50 or more. For that kind of investment, I want to know some specifics on what to expect.


Because of this desire to know some measured criteria impact, a series of tests have been performed to allow this to be better understood. For convenience, several Athearn blue box engines were used as test beds. The idea is to allow the motor change with the minimum change in the other features on the engine. In this regard, the motor may not be demonstrated to its best performance. The increments between the various motors should be qualitatively meaningful.

The testing performed is the standard test series defined in earlier posts. These tests are done on a pure DC signal. There is no pulse wave modulation from the power supply, ever.

For this series, the practice of adding weight to the engine in increments of approximately 150 grams was used in every case. As has been shown, engine weight is a significant driver to the resulting performance. The various motors and the mounting items will impact the actual engine weight. It is important to understand if the increment is due to an improved motor or the increased weight. A resulting engine with good performance is a good result, but it if it can be achieved with simply adding weight to the original engine, so much the better.

A number of motors have been used in these tests. Multiple versions of the various motors have been examined. Not all motors or motor types have been used in any given engine test bed. Typically each test bed saw four different motors. In some cases the text number was three and in others it was seven.

The motor types and number of variations are as follows:

1. Three early Athearn blue box round jet motors with grey flywheels.

2. Seven gold rectangular Athearn blue box open frame motors with brass flywheels.

3. Three P2K standard rectangular open fame motors with brass flywheels. These generally have smaller flywheels than the other options. Smaller fly wheels equals lighter weight.

4. Three P1K F3A can motors with brass fly wheels. Again the fly-wheel is smaller than the blue box wheels.

5. Ten Helix Humper can motors with brass fly wheels. These are new from old stock.

6. Three Mishima 1824 can motors with brass fly wheels

7. Three Mishima 1833 can motors with brass fly wheels

8. One round Sagami can motor with brass fly wheels

9. One Roco rectangular open frame motor with brass fly wheels

These motors with their weights are shown in the next several charts. As of this writing it all of the motors have fly wheels or are available to be photographed. Some are installed awaiting a test. As pictures are taken this post will be updated.

motor1

motor2

motor3

motor4

motor5

Most of these motors are used. A few were new in sealed packaging. They are from old stock.

It is anticipated that this will be an ongoing study. The option exists to add additional motor types, including recent released Kato or Athearn Genesis motors.

This series generates a significant amount of data. For this reason, each test bed engine will be addressed in separate posts. Each of these posts will stand alone.

As is the case with each test be seeing multiple motor types, each motor will see multiple test beds.

The test beds configurations will include F7, GP38, GP40, SD9, SD45, U30B, U33C and Train master. These will have both metal and plastic side frames. The configurations will include inside and outside frames. Some will have stock BB wheels and some will have RTR NiAg wheels.

All potential conclusions will not be discussed, but the obvious ones will be compared as appropriate.

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