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Specialist engine help needed

1.3K views 7 replies 5 participants last post by  Holmes  
#1 ·
I'm current building another gpz900r engine based fighter. But I want to do something different.

Standard gpz900 engine runs an oil cooler and water cooled, I need to know is there anyway this engine can be converted so it does not need water cooling I don't want a Radiator on this bike I want it nice and clean.
 
#3 ·
No. Long story short, a water cooled engine needs a relatively low, stable temp to do its thing without turning the engine into a formerly-spinning lump of scrap.

Even if you somehow radically altered the engine so it had sufficient fins to dump the heat, air cooled bikes run really hot. Because heat given off is mostly proportional to the DIFFERENCE in temp (and density of absorbing medium) you can't just add more fins and run cooler - area is a secondary factor. Because they run hot, the internals have looser tolerances to allow for changes in dimensions that come with widely changing temperatures. As a result they also have lower compression, so do things with timing etc that would maybe cause detonation on a bike with higher compression. As a result, air cooled engines make less power - not because making more power makes more heat (though it does) but because you can't even build to the specs needed to make that power unless you can control heat. If somebody tried to build an air cooled engine with specs like a gpz900, it would run like shot and have a short lifespan.
 
#6 ·
there are aftermarket and newer radiators that may look beter and be smaller than what you have, but no, you can't just deprive it of water, except maybe for one time use then replace the motor


I would peek at aftermarket rads, they tend to be slimmer and smaller. You might have to fab some mounts, but in the end it might be worth it.
 
#7 ·
Yup, a smaller / relocated radiator may work. If you mount fans on it and / or run a duct to it, you can hide the radiator almost anywhere. Some race bikes have them mounted under the seat. IMO that is the best of both worlds!