Toyota Unveils Fuel-saving Technologies for New Prius

Wow.
Sounds like a lot of significant changes at the very heart of the vehicle...the engine.

I suppose my only concern would be wondering how many of these changes have been road tested over a long period of time in other formats or vehicles? In other words, being such a new engine, embracing so many changes, how reliable may it be or not be over a long period of time?

But I'm not seeding the clouds for problems. It really sounds like Toyota pushed the envelope in trying to improve the engine. Hopefully they got it right. Glad to see the groundbreaking. It's better than standing still.

 

One of the virtues of Atkinson cycle, assume this could not be possible with standard Otto cycle without dramatically increasing pumping losses.

 

The intake manifold is composite (high density polymer) (not magnesium or aluminum. Pretty common in engines now.

Why does it still have a crank pulley? Doesn't drive anything.

 

Perhaps this engine is going to be used in other applications. My 2013 Prius has a pulley that's not used for anything.

 

And if so, it might be calculated weight for harmonic balancing.

 

Agree most likely IS a harmonic balancer.. Most folks don't know how critical this can be to the life of the crankshaft. e.g. to damp torsional resonances in the crankshaft that can occur at certain engine speeds.

 

Interesting. I can't stand a knocking engine. Hopefully Toyota gets that right.


iPad ?

 

when my engine knocks, i let it in. problem solved.

 

I was wondering the same thing.

 

Balance?

 

As posted above, it's a harmonic balancer. To make a different one for the Prius is just silly. The same engine design is used in many other Toyota models, so they just reached into the parts bins and grabbed the one they already make. It just happens to have a pulley on it. If it ever got too tight in the engine compartment for that pulley, I suppose they would have to remove it, requiring them to stock one more part. But for now, it's more efficient to use the same part on many models engines.

 

As David says 1.8 engine is used in Corollas and Scions. I'll bet the part # is the same as in other applications.

 

I should have remembered that's what a pulley that doesn't "pull" anything was for. I'm almost 60. sigh.

Not all engines have had harmonic balancers.
The D15Z1 engine in both of my 92 Honda Civic VXs had only a pulley - no harmonic balancer. Later models included the balancer. My second Civic VX made it to 238K miles without a balancer incorporated within it. It was solid metal - no rubber isolator or "fluid filling".

I know this because I had a special method of removing the pulley from the crankshaft when replacing the timing belts. Honda had an SST that you could buy/rent to hold this crank pulley while loosening the bolt. I made my own special service tool.

 

Thanks again for the custom PIDs for the Gen 2, usbseawolf2000.

Just installed Torque on another android phone with a larger screen and faster processor. Now Torque
loads and exits much more quickly.

 

So, with all this friction reduction, what happens when the fourth gen descends a mountain pass? "B" is not going to be as effective (it was not enough in GII or GIII already). Are we going to smoke the brakes? The battery gets "fully charged" and regen. quits after one to two km.

Something to wonder about. I wonder if Toyota have tested it?

 

(Briefly Stated)
Selecting "B" on the shift lever does not rely on engine friction to invoke deceleration. Engine braking in "B" utilizes pumping losses of the ICE whereby the excess momentum of the mass of the vehicle is driven into the ICE without fuel for combustion. Forcing engine rotation without fuel, piston movement is slowed by the compression and vacuum forces within the cylinder. This braking force is variable by modulating the ratio of ICE RPM to MPH by the CVT.

 

plus it is 20% lighter

 

Posts collector?