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Sep 01, 2009

Tech Corner: UCE Lubrication

Tech Tips

For the UCE engines I am starting a series covering some of the design aspects. We are starting with the lubrication system for no particular reason other than the fact that we got a really cool video and slide presentation from the factory today (shown below).

Royal Enfield was the first motorcycle with a dry sump oiling system. In short this meant that the crankcase was empty and the oil is stored in a tank (internal to the engine). Pressurized oil is fed to the critical components and drops into the crank crankcase where it is picked up by a second oil pump and sent to the head. In a wet sump system like the new UCE engines the crankcase is full of oil. When the engine starts a pump picks up the oil, pumps it through a filter and then directs it to different areas under pressure. Because the clutch and transmission are all part of the engine case they all run in the same oil. The real advantage is that in the UCE we can move a lot more oil under a higher pressure than we could in the oil machines.

The new system will deliver 9.5 liters of oil every minute to the critical components. The pumps will not vary more than 50cc’s in it’s mission. This extends engine life and provides better cooling. The new engine also has hydraulic valve lifters which require oil under pressure to operate. In the older engines the oil which was scavenged form the engine sump was fed to the rocker bearing and lubricated the valves and rocker arms. This oil was delivered in fits and starts under low pressure depending upon how much oil the pump could scavenge at any given time. This was fine for the older engines but limited the amount of heat is could carry away. In the new engine oil is delivered simultaneously to the crankshaft, hydraulic lifters and cylinder head through three separate oil passages and all under a constant pressure.

The R&D guys at the factory made a very cool video by removing the back of a transmission and covering it with glass so you can see how the transmission is lubricated during operation:

Here is are some slides from Royal Enfield’s engineering team that detail the lubrication system and provide some interesting diagrams and illustrations:

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