I was just reading a headline in the newspaper ( remember those?)
Nissan has developed an engine that somehow has “variable compression” a two liter variable compression turbocharged engine that they claim will be 20 to 30% more efficient.
It made me think about a car my father bought in the 1970’s , a Honda Civic with a CVCC engine.
That car got an honest to God 50mpg on the highway and was reliable as a watch.
The key was an ingenious head design that had a small chamber just off of the cylinder that had its own intake valve and that’s where the spark plug resided. They would charge that little chamber with a rich mixture that would flame easily, while simultaneously charging the main cylinder with a very lean mixture that would be ignited by the rich charge burning. See below
They managed to achieve this extraordinary fuel mileage with carburetors , yes two of them. Instead of fuel injection. One carburetor created the rich mixture for the small chamber and one carburetor created the lean mixture for the main charge. Ingenious! It was a complicated design to be sure and mechanics probably hated them. But that Civic my dad had ran trouble free for the ten years he owned it.
I’ve often wondered why they discontinued that design. 50mpg is kinda the holy grail of fuel efficient cars. Just imagine what they could’ve done with modern electronics and fuel injection.
Nissan has developed an engine that somehow has “variable compression” a two liter variable compression turbocharged engine that they claim will be 20 to 30% more efficient.
It made me think about a car my father bought in the 1970’s , a Honda Civic with a CVCC engine.
That car got an honest to God 50mpg on the highway and was reliable as a watch.
The key was an ingenious head design that had a small chamber just off of the cylinder that had its own intake valve and that’s where the spark plug resided. They would charge that little chamber with a rich mixture that would flame easily, while simultaneously charging the main cylinder with a very lean mixture that would be ignited by the rich charge burning. See below
They managed to achieve this extraordinary fuel mileage with carburetors , yes two of them. Instead of fuel injection. One carburetor created the rich mixture for the small chamber and one carburetor created the lean mixture for the main charge. Ingenious! It was a complicated design to be sure and mechanics probably hated them. But that Civic my dad had ran trouble free for the ten years he owned it.
I’ve often wondered why they discontinued that design. 50mpg is kinda the holy grail of fuel efficient cars. Just imagine what they could’ve done with modern electronics and fuel injection.