Explanation of some bike terms please?

[m1spw]

[quote=gilera SMT 50 description]Clutch - Multi-disc in wet sump[/quote]
Can someone tell me is that normal? It sounds good (if you can't tell, I have no idea about bikes)but im not sure what it is :confused:

Also whats the difference between a liquid and an air cooled engine, in terms of performance and mod-ability?

Thanks guys

[Mon Ami Mate]

Most modern bikes have wet sumps (the oil is contained in the engine). Earlier bikes tended to have dry sumps (oil contained in a separate tank and pumped to the engine). Most bikes also have multi-plate clutches - the more plates you have, the more friction you can generate and the less amount of wear each plate is subjected to. So, what you are describing is typical of a modern motorcycle.

Water cooled engines have a water jacket around them and a radiator. This allows the engine internals to run at higher temperatures than an air-cooled engine. Most bikes are now water cooled, with a few rare exceptions. Air-cooled bikes tend to fall foul of noise and emissions regulations - the water jacket of a water-cooled engine deadens the sound generated by the engine and also allows optimum burn characteristics, resulting in lower emissions.

>> Edited by Mon Ami Mate on Wednesday 3rd August 15:41

>> Edited by Mon Ami Mate on Wednesday 3rd August 15:43

[Pigeon]

...also...:

- Bike clutches, unlike car ones, generally operate submerged in oil (there are exceptions).

- Air cooled engines tend to be easier to piss about with as they are simpler and don't have water in.

[bikerkeith]

You may also see reference to oil cooled engines. Examples include the Suzuki GSXR engine from the mid 1980s which still lives on powering Bandits, also some old Yamaha engines. It actually means air cooled but in the case of the Suzuki engine, there is a high volume/low pressure oil supply that sloshes around inside the engine to help cool it down, linked to an oil cooler at the front. Although its a very old design, it can be tuned to produce prodigious amounts of power.