Harley-Davidson engines refrigerated by water: the twin-cooled system
We are going to deal with the theme of the new liquid cooling in the American bichilindrums: many years ago it was speculated with liquid cooling in Harley-Davidson's Big Twin engines and finally arrived during 2014, under the famous Rushmore project.
Its implementation responds more to emission control reasons (for this it is important to stabilize the engine temperature) whose regulations are increasing as faithful as possible with respect to its origins.
Development history
An engine transforms chemical energy into mechanical energy, generating large amounts of heat during the process. For the proper functioning of the engine, this heat must be controlled in some way in order to avoid damage to the components. Traditionally, air cooling is used in HD engines, providing cylinders and butts (the motor parts where it is most heat) of large aluminum fins through which the air flows while circulating with the vehicle. This air passes "steals" heat to the engine, lowering its temperature.
It must be said that the liquid cooling implemented by Harley-Davidson differs from the traditional one, where the cylinders and butts are mounted inside some "wet shirts" through which the water circulates.
To preserve the traditional air cooling appearance an experienced concept is used a few years ago with the XR1200 models, where the butts were equipped with an internal oil circuit connected to an exterior radiator (precision cooling) that managed to reduce the operating temperature of the hottest parts around the exhaust valves.
"Invisible" solution
After successfully experiencing this system in sports models, Milwaukee's factory simply had to replace oil with water and almost had a liquid cooling system.
But not everything is as simple as it seems. As happened with the ABS braking system, the challenge was completely hiding the system so that it did not affect the classic motorcycle aesthetics.
The solution consists of dividing the water radiator into 2 parts, which are hidden into the lower fairies.
A mixture in equal parts of water and coolant, driven by a pressure pump located below the voltage regulator, in the front of the chassis, circulates inside them. If the case requires it, two fans mounted after each radiator will be activated.
The filling plug, which regulates the general pressure of the system, together with the expansion tank are located within the lower right fairing.
The system has a temperature sensor and a thermostat that cuts the passage of the refrigerant to the radiators when the engine is cold, thus reducing the time it takes to reach the operational temperature of the engine, it is then when the Step towards radiators to cool the circuit.
Models and applications
Together with the benefit that the temperature control provides to comply with the increasingly strict regulations there are other points where improvements are achieved thanks to the liquid cooling system.
One of them is that the sensation of heat from the engine has been reduced in a sensitive way for the driver, and together with the new location of the exhaust collectors, the comforter's comfort also improves.
The other advantage is that it has been possible to increase the compression of the cylinders, which have gone from 9.6 to 10: 1, therefore increasing the power of the propeller.
The present and the future
Currently, models with “Twin Cooling” liquid cooling, as the mucus calls it, are certain versions of the Touring range. However, it is very likely that the application will extend more to more models in the next years ...
Frank Burguera
10 comments
Buenas, alguien sabe si se puede anular el sistema de refrigeración liquida de las milwaukee?
Quiero quitarles las perneras pues da mucho calor a mi y a mi pareja, y no siento que refrigera nada, al anular las perneras, el aire circularia mucho mejor, como las road glide special, yo tengo yna road glide ultra 2017,
Si alguien ha podido hacer algo, rogaria me informaran, a veces es insufrible el calor que se pasa y rodando, muchas gracias
Yo tengo la Electra glide ultra clásica del 2014, y con poco más de 20000 km. Y fuera de garantía me tuvieron de cambiar la bomba , se envío carta a Harley España y ni contestaron , y ahora tiene 55.000 km. Y vuelve a tener el mismo problema. Ahora me pondré en contacto con el concesionario y haber si Harley España dice algo, porque hay muchos más casos y todos en estos modelos y años.
Tengo una street glide 110 2016 cvo con 10,000 kilómetros que acabo de comprar que me recomiendan para protejer mi motor
En menos de 15 meses, tuve que cambiar 2 bombas de mi electra. Afortunadamente las reemplazaron por garantía. Se nota que este sistema no está dando los mejores resultados. Al menos conozco 3 casos similares.
Este sistema esta provocando continuas averías de la bomba del agua de mi moto (Harley Davidson Electra Glide) , sobre todo en los viajes en verano ; cuando la moto apenas tenía 30 .000 km, por desgracia pasada ya la garantía , por lo que en Harley Davidson (Cantabria-España) , me dijeron que tenía que abonar 700 € de la bomba mas la mano de obra, lo que me parece inadmisible considerando que dicha rotura es por defecto de fabricación de la bomba, pues hablando en foros con otros propietarios, mi caso no es aislado, siendo muchos propietarios de los modelos Touring los que han tenido el mismo problema. Por lo que considero que Harley Davidson debería sustituir de forma gratuita dicha pieza., reitero defectuosa en muchos modelos.