Gas engine breakthrough?

[Mailman]

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.

 

[peanut]

yeah thats pretty amazing . Pity it didn't get developed .
Everyone is going electric now and I for one welcome it as long as we can still collect and run our classics . We'll probably end up being outlaws like some of those sci-fi films riding the streets to secret meets in the dead of night with the emissions Police chasing us on electric bikes

 

[Tomterrific]

Stratified charge. I always thought it would be good for a Wankel because of the large combustion surface. The new Direct Injection Engines should have some sort of stratified charge.

Tom

 

[Mailman]

Stratified charge. I always thought it would be good for a Wankel because of the large combustion surface. The new Direct Injection Engines should have some sort of stratified charge.

Tom

Yeah, it’s very clever stuff. You gotta give it to Honda. They have always had superb engineering.

 

[YamadudeXS650C]

Yeah, it’s very clever stuff. You gotta give it to Honda. They have always had superb engineering.

Hmmmm.........they seemed to have failed miserably in Formula One. Quite an international embarrassment.

Formula One News, Sept. 15, 2017:
"After three disastrous seasons, the McLaren Formula One team is cutting ties with Honda and switching to Renault as its engine supplier next year.

The longtime powerhouse team has been struggling near the bottom of the pack, due in large part to the unreliability and lack of power provided by Honda’s turbocharged motors."

David Hobbs, Formula One commentator and Honda dealership owner, has been almost speechless about the debacle.

 

[azman857]

In 1977, July I think, I went to the local Honda dealer and bought a new Honda wagon. 1500 with 4 speed. Had it for 5 years. I enjoyed it. Ran great. Handled OK.

 

[TwoManyXS1Bs]

...Nissan has developed an engine that somehow has “variable compression” ...

I wonder if they're using this:

http://www.xs650.com/threads/the-animated-engine-thread.40156/page-3#post-413600

 

[YamadudeXS650C]

Oh for sure Honda has made some great cars. Bought a nice new Accord 2-door 4 cyl in 2006, but my favorite was a 1999 6 cyl 2-door Accord with leather, pictured here towing my first XS, the '76, on the day I bought it.

For years I've been on the lookout for a nice silver S2000 with that sweet, technologically brilliant Vtec engine.

 

[MaxPete]

I have heard that Honda recently overtook Briggs & Stratton as the world’s largest engine manufacturer. There is another funny story in the industry that the only reason Honda builds cars and motorcycles is to help them sell their engines.

I’ll dig around and see if I can figure why they dropped the CVCC engine. I suspect it had to do with cost and the development of lower cost catalytic converters.

Pete

 

[YamadudeXS650C]

I recall that Edd Chyna did a cool show on restoring a CVCC engine back to its 50mpg (or better) glory. Its such a loss having him gone from that show......

 

[59Tebo]

As long as the government subsidizes oil companies to pump dinosaurs out of the ground, instead of (American?) auto manufacturers to develop truly efficient engines (they can, they just don't have the incentives), then you won't see any high-efficiency gasoline powered cars out there. What do you think? There hasn't been any real technological advances in gas engines (let alone construction of new refineries) in almost 40 years. Why? There's too much money to be made at the expense of the consumer and environment! End rant...

 

[Mailman]

I wonder if they're using this:

http://www.xs650.com/threads/the-animated-engine-thread.40156/page-3#post-413600

That’s a cool video 2M, they did say in the article that they achieved variable compression by changing the piston stroke but they gave no details.

 

[YamadudeXS650C]

I was in Pennsylvania a couple weeks ago, and was pleasantly surprised to see a Tesla charging station being installed.

 

[Mailman]

At the time that engine was developed you have to remember what was going on. Skyrocketing fuel costs , gas shortages, long lines at the gas pumps, they lowered the National speed limit to 55mph in order to conserve gas. Big Detroit cars with big V8 engines became practically worthless overnight. You could buy muscle cars cheap as chips. Detroit could respond to the demand for small cars fast enough, they were striking deals with foreign car makers to rebadge their small cars.

 

[Mailman]

Oh for sure Honda has made some great cars. Bought a nice new Accord 2-door 4 cyl in 2006, but my favorite was a 1999 6 cyl 2-door Accord with leather, pictured here towing my first XS, the '76, on the day I bought it.

View attachment 109521

For years I've been on the lookout for a nice silver S2000 with that sweet, technologically brilliant Vtec engine.

I had a 2000 Accord that had that V-Tec engine in it. It was a marvel, it was more powerful than the much larger V6 I had in my Chevy Lumina.

 

[fredintoon]

At the time that engine was developed you have to remember what was going on. Skyrocketing fuel costs , gas shortages, long lines at the gas pumps, they lowered the National speed limit to 55mph in order to conserve gas. Big Detroit cars with big V8 engines became practically worthless overnight. You could buy muscle cars cheap as chips. Detroit could respond to the demand for small cars fast enough, they were striking deals with foreign car makers to rebadge their small cars.

Hi Mailman,
back when me and a bunch of others started building the Concorde aviation jet fuel cost 17Cents an Imperial gallon.
By the time of Concorde's first flight aviation jet fuel cost had risen to 17cents a teacupful.

 

[Mailman]

I believe that Fred. I can remember waiting in LONG lines to get gas. Once I must’ve been in a line that was half a block long , only to pull up to the pump and find out the station had no more gas. We thought it would never get better. I had an employer that would have me take his car , on the clock , to go fill it it up for him, because he didn’t want to wait in those lines.
I never thought I’d see the day when all the top selling vehicles are BIG SUV’s and pickups.

 

[gggGary]

I believe NOX standards were what killed stratified charge. The Metro from the same era got 50mpg from the 3 cylinder suzuki til NOX regs came in, they retarded the timing ten degrees and lost 10mpg. us scuff-laws had the fix......... NOX generation is higher at high combustion temps; lean mixture, early ignition timing, and high compression all create that. That's why the push for variable compression, if you can run the air unrestricted into just enough compression to create the power needed you can get both MPG and low emissions, I think one of the Japanese makers is coming out with a compression ignition gas motor, with spark for starting and idle, continuous fuel injection allows it without blowing off the heads.

 

[Mailman]

I had one of those early three cylinder Metro’s. Motor was about the size of a Igloo Playmate cooler! But it was a wonderfully snappy little motor, and it just sipped gas!
Another thing about those early civics and that Geo Metro that made them so fuel efficient was their very light weight. They weren’t “burdened” with safety features that add complexity and weight. Conversely if you were in an accident, you were GONNA take the hit.

 

[xjwmx]

they did say in the article that they achieved variable compression by changing the piston stroke but they gave no details.

Here it is in detail...