[Mr Twisty]

Originally Posted by DGthe3

I'm in slightly over my head here (its been quite a while since Thermo & Heat), but I'll give it a whirl ...

an engine works because hot gasses push against a piston. In doing so, they expand. As they expand, they cool.

It would seem to me that a cold cylinder would rob heat from the expanding gas -causing it to lose pressure faster, therefore producing less force against the piston (causing less torque, and by extension less power). Conversely, a hot cylinder would allow for more heat to be used to push the piston.


Now, as for the 5 stroke ... its interesting, but an alternate solution exists: leave the intake valve open for a bit on the compression stroke. The net result is more or less the same, but it requires essentially 0 extra parts.

I'm in way over my head here but I always enjoy watching another person think outside the box... Like this 5 stroke engine.

I'm thinking expanding hot gas in a cool cylinder does cool but cool air (or carbon monoxide) is more dense. Probably way off base, but anyways.....

Allowing pressure into the intake from the cylinder would be the same as retarding timing wouldn't it?

They're claiming there's enough energy left in spent exhaust gas to do more work. According to wiki, modern gas engines are still pretty inefficient.