Quote:
Originally Posted by rmay635703
Looking at this thread (because I have long ignored looking at the Bourke engine) I have often wondered how we might use ceramic on the head and walls to keep the hot exhaust gasses there while also not bothering to dissipate them through the material. An ideal engine would not have any active cooling at all  |
Unfortunately an engine that does not allow heat to escape to the cooling system won't pass emissions these days. The NOx emissions would be too high. In the 80's in Japan they made a ceramic diesel engine once and put it in a test car. It returned very very good mileage numbers, but no way would it pass emissions.
Also NOx emission was the main reason for aluminum heads to appear on production cars and not weight savings. Aluminum conducts heat much much better than cast iron.
You just can't win :P