Piguin
Reader
9/23/24 2:21 p.m.
Apparently Porsche filed a patend for a six stroke engine, or to be more Porsche like, "Method for a Combustion Machine With Two Times Three Strokes".
The design mixes 2 and 4 stroke design, with 2 compression and power strokes for each exhaust stroke, using scavenging before the second power stroke, all thanks to a rather complicated dual rod setup.
Thoughts?
Not the first time I've heard of a 6 stroke engine. Hope it helps, but I'm not holding my breath over a patent.
Intake
Compression
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Re-compression
Combustion
Exhaust
No second exhaust stroke? Usually these 5/6 stroke engines are taking advantage of energy still left in the exhaust after the first exhaust stroke.
Driven5
PowerDork
9/23/24 4:26 p.m.
It's interesting. A few key items to look at. First is the geometric path resulting from the particular planetary arrangement causing 2 long-TDC's + 1 short-TDC and 2 short-BDC's + 1 long-BDC per 3 revolutions. Second is the intake cam lobe having a second smaller peak while running 1/3 engine speed. Third is the exhaust ports in the cylinder wall between short-BDC and long-BDC. The result seems to be as follows:
- Primary intake stroke to short-BDC with intake valve(s) open.
- Primary compression stroke to long-TDC with all valves and ports closed.
- Primary combustion stroke to long-BDC, revealing secondary exhaust ports below short-BDC accompanied by partial intake valve opening for brief secondary 2-stroke like 'scavenged' exhaust/intake during time below the short-BDC.
- Secondary compression stroke to long-TDC with all valves and ports closed above short-BDC.
- Secondary combustion stroke to short-BDC with all valves and ports closed.
- Primary exhaust stroke to short-TDC with exhaust valve(s) open.