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-   -   New Civics to have Direct Injection + Atkinson valve behavior, 45mpg? (https://ecomodder.com/forum/showthread.php/new-civics-have-direct-injection-atkinson-valve-behavior-19886.html)

danwat1234 12-25-2011 02:50 PM

New Civics to have Direct Injection + Atkinson valve behavior, 45mpg?
 
Src, google:"Honda Previews New Engine Lineup: Direct Injection and CVTs Coming"

Looks like new cars from Honda are finally going to have Direct Injected engines, and these OTTO cycle engines can also function as Atkinson cycle engines when demand is low (compression stroke is shorter than power stroke) for even more fuel savings. They give an estimated 10% fuel savings, so maybe 45MPG highway for the regular Civic?
The primary mode for the engine is OTTO, then secondary is Atkinson.
I like. Now we just have to wait for homogeneous stratified charge OTTO cycle engines..no spark plugs during low demand so it functions like a diesel .. 14:1 compression or so. Beyond this, there isn't anything else you can do to an OTTO cycle to make it more efficient (from what I've researched).
Diesel fuel powered Atkinson engines are one idea, or higher compression with OTTO cycle maybe.

The new Civic will have 148HP instead of the now 140HP. I think the engine will start with the 2013 cars.

If they put the new 1.8L in the Civic, then they could very well get better than the 42MPGhwy that the Chevy Cruze gets, making the Civic the most efficient non-hybrid non-diesel compact car out there. If it can get 44MPGhwy, then it'll best the 43MPGhwy VW TDI.

The current Civic with the aerodynamic mods is rated at 41MPGhwy and so I think it's entirely possible to get to 44MPGhwy or higher with that model with the new engine, and at least meeting the Chevy Cruze with the non-eco Civics (from 39MPGhwy to 42MPGhwy).

gone-ot 12-25-2011 04:03 PM

...sounds V-E-R-Y interesting. The Cruze 1.4LT doesn't have DI (yet), but rumors are that it'll probably get it in model year 2013.

tjts1 12-25-2011 06:22 PM

I'll believe it when I see it on the dealer lot. Honda has been BSing about DI for years. Good luck playing catch up.

user removed 12-25-2011 07:46 PM

DI in the garage, 100k warranty. 5-60 free roadside assistance.

regards
Mech

mans 12-26-2011 10:20 PM

new ford focus with ecoboost coming out with gasoline direct injection

Peter7307 12-28-2011 12:29 AM

An interesting item and it will be also interesting to know how much of the fuel savings will be due to the engine and how much to the CVT.

Peter.

cfg83 12-28-2011 12:58 PM

danwat1234 -

Would this be similar to the HCCI stuff that GM has been fiddling with? :

GM's HCCI engines now run from idle to 60 mph!

CarloSW2

redpoint5 12-28-2011 01:05 PM

Quote:

Originally Posted by danwat1234 (Post 276258)
Looks like new cars from Honda are finally going to have Direct Injected engines, and these OTTO cycle engines can also function as Atkinson cycle engines when demand is low (compression stroke is shorter than power stroke) for even more fuel savings.

How can a compression stroke be shorter than a power stroke? Are the con-rods variable length or the crankshaft morphs?

Also, why haven't gasoline engines been DI from the beginning, with no spark plug?

Last question, what is the difference between OTTO and Atkinson?

It seems to me the most efficient car would have a puny motor (3 cylinder 1L perhaps) and a turbo charger. Make this diesel with electric assist and regen and you would have one heck of an efficient vehicle.

gone-ot 12-28-2011 01:55 PM

Quote:

Originally Posted by redpoint5 (Post 276613)
Also, why haven't gasoline engines been DI from the beginning, with no spark plug?

...because Diesel engines rely upon the 'self-ignition' point of fuel to run so no ignition-system is needed; and, they produce LOT's of torque but only at slow speeds (typically <3-4,000 rpm).

...Gasoline engines require a spark-ignition system (coil, distributor, wiring, plugs) to ignite the air-fuel mixture at a precise(*) timing so that they can achieve much higher engine speeds (6-7,000 rpm) and thus higher power (but not torque) than Diesel engines.

...even the "new" HCCI engines (diesel-like operation using gasoline) will use BOTH Compression Ignition (CI) (at light loads) and Spark Ignition (SI) (at high loads) operation...Direct Injection (DI) with gasoline is "trickier" than with diesel, because of gasolines' lower self-combustion temperature.

...why SI before DI? It was easier to get electricity to occur quickly than it was to get mechanical injectors to squirt quickly.



(*) = gasoline engine power is very sensitive to changes in ignition timing.

redpoint5 12-28-2011 02:28 PM

Quote:

Originally Posted by Old Tele man (Post 276622)
...because Diesel engines rely upon the 'self-ignition' point of fuel to run so no ignition-system is needed; and, they produce LOT's of torque but only at slow speeds (typically <3-4,000 rpm).

...

Wonderful explanation, thank you.

It's my understanding that diesel engines operate at lower RPM because the fuel burns more slowly. This implies that if they operated at higher RPM the fuel/air mixture would be evacuated from the cylinder before it completely burned.

With the injection technology of today, wouldn't it be possible to precisely inject fuel at the higher RPM range that gasoline engines turn? Increasing the CR to allow for CI in a gasoline engine would produce more torque would it not? Exchanging greater torque for fewer maximum RPM seems like a good trade off.


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