How to Design the TOYAN B400 Boxer4 Horizontally opposed 4-cylinder engine KITS | EngineDIY

Born in 1963, the Porsche 901 is the first generation of the world's popular 911 sports car. In addition to its iconic appearance, it is equipped with the Type 901/02 engine, which is a continuation of Porsche's traditional air-cooled, horizontally-opposed structure. Many players were eagerly looking forward to this engine, so we decided to launch a miniature version based on the Type 901/02 engine. In view of the limitations of miniaturisation itself, we chose to retain Porsche's unique air-cooled horizontally-opposed design language and designed and manufactured the FS-B400A horizontally-opposed engine.

The body of this TOYAN B400 BOXER 4 horizontally-opposed engine is CNC-machined from all-metal, with black as the dominant exterior colour, and features the Type 901/02 engine's most distinctive air-cooled radiator. To accommodate the miniaturised conversion, the four-valve structure of the prototype has been changed to a two-valve configuration to better match the combustion chamber structure.

Depending on the direction of possible improvements for later upgrades, we lengthened the camshaft to allow room for the addition of a distributor assembly and were able to provide more accurate ignition control.

For the reference engine timing drive, the double-row chain has been replaced by a toothed timing belt to continue the compact and precise transmission characteristics.

The design of double compression pulleys + synchronous idler pulleys synchronous tensioning mechanism controls the height dimension, and at the same time facilitates the adjustment and disassembly of the timing mechanism.

In the starter mechanism, a new structural design is added, and the compact tensioning design ensures good meshing of the starter belt, prevents slipping and tooth sweeping phenomenon, and naturally prolongs the service life of the starter belt.

The most characteristic air-cooled radiator design combines the dual advantages of aesthetics and practicality, and the round belt drive gives the cooling fan a surging power of nearly 30,000RPM, which brings the engine strong and efficient cooling ability and more stable power output.

As the first horizontally-opposed model based on the Type 901/02 engine, through continuous optimisation of the design and improvements, we are confident that this new engine, with its unique design style, will be loved and praised by engine enthusiasts.

The above are our engine building notes, which we are happy to share with you and look forward to your suggestions and advice. We will continue to update and release the pictures and video materials of the manufacturing process.

Stay tuned ......

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