Talk:Bourke engine

From Wikipedia, the free encyclopedia

Where is the reference for the claim of nitrous oxide production problems? It's very logical and "sensible" but those who build Bourke engines say that it doesn't happen. In any event, wouldn't that be primarily a result of the lean fuel-air mixture and easily remediable by running a richer mixture and trading away the assitional fuel economy in order to gain the simplicity of design?

New Comment

My understanding of nitrous oxide production in the bourke engine is that it does not happen. This is an "explosion" engine with a flame front of over 5000 ft/sec. At the time of the explosion their is peak temperature and presure and all the fuel is consumed. The short time does not allow for the production of nitrous oxides. As soon as the piston starts "shooting" down the cylinder the expanding gasses absorb the heat that is contained in the piston and the cylinder and lowering the gas temperature below that necesary for the production of this oxide. Their is no burning occuring while the piston is moving down the cylinder, only expansion which causes cooling. This leads to the low exaust temperature of around 200F degrees.

thank you for listening to my thoughts.....sno

[edit] Bourke engine simplified explanation....

I would like to add something like the following:

Quote

The Bourke engine should be considered an "explosion" engine due to the extremely fast burn time of the fuel air mixture.

The rising piston compresses the mixture heating it, due to the cool piston head and cylinder walls the mixture is not heated enough to start a burn. The piston "latches" at top dead center do to the action of the scotch yoke. Spark plug fires causing an explosive burn. All of fuel is burned. Sharp rise in pressure causes scotch yoke to "unlatch" piston. Piston moves down cylinder, expanding gasses following piston cause cooling of piston and cylinder walls. Since all of fuel was burned during "latching" of piston no fuel is being burned at this time, no heat is being added, all expansion results in cooling. When piston reaches the bottom of the cylynder it again "latches" until "unlatched" by the explosion in the opposite cylynder. This gives time for scavaging of explosive gases.

The mixture must be lean enough so that compression heating of the mixture does not cause it to ignite prior to the "latching". If this occurs engine will not run, or will run rough.

The maximum pressure on the piston occurs right after the release of the piston from top dead center. It is not spread over the whole length of the piston travel as in a conventional engine. For this reason this is an extremely high torque engine.

The complete burn of the fuel while the piston is "latched" gives this engine its high efficiency and low emmissions.

The cooling caused by the expanding gases, behind the piston head and the non burning of fuel while piston is traveling, causes the low temperature exaust gases. This also prevents dieseling during the next compression cycle because of the cooling of the piston head.

Unquote

I would like to add something about how the speed is controlled and the reason there is low vibration, but do not have the understanding for that.

Thank you for your comments.....have fun......sno2

[edit] Should this be in this category......???

The Bourke engine was built and tested and was in pre-production at one time. I believe that it is a proven engine and not a proposed design.