Five stroke bicycle engine concept?

xXNightRiderXx

Active Member
Jan 12, 2017
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Has anyone ever heard of a five stroke engine? Sounds crazy, right? Wrong. It is perhaps the most genius thing I've ever heard of! A five stroke engine is basically a four stroke engine with a separate cylinder that acts as an expansion chamber, but instead of just drawing gasses out of the cylinder, utilizes the heat of the exhaust in a fifth stroke, the extended expansion. This is a low pressure cylinder that uses the expansion of the hot exhaust gasses to add another power stroke, improving the efficiency and power to weight ratio of the engine. Now, what if someone put one of these on a bicycle? How cool would that be?
 

xXNightRiderXx

Active Member
Jan 12, 2017
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5 cycle engines have been around for about 100 years, they even used the expansion cylinder in steam engines. Engineers choose turbos over 5 strokes because you don't need to change the engine itself.

http://pergelator.blogspot.co.uk/2012/10/nothing-new.html
For cars, the slight increase in power may not be worth it, but on a bike, where there is much less weight to push, that small power increase may mean the difference between getting gold vs silver.
 
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xseler

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Apr 14, 2013
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I'm cautiously awaiting the release of the Pan 18...................it's rumored to run on fairy dust. It should be able to fly like the wind!






(I apologize for those willing to look!!)