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dan45mcc

2010 Silverado E85 Hybrid

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I believe this is a "hybrid" and a flex fueler. Not exactly how I'd like to see these two technologies combined. Imagine if the new Insight or Prius was FFV, what a dent that'd make in petroluem usage! But I am pretty sure this is the first E85 hybrid vehicle we've seen here, correct? Gotta start somewhere...

 

I don't see how the Prius being a FFV would make near as large as a dent as the Silverado. The Silverado uses much more fuel so the savings will be much larger, combined with the fact that the Silverado in general is a much higher volume vehicle and it makes an even larger dent in the use of fossil fuels. Of course that depends on the amount that GM actually produces and sells.

 

I KNEW I heard of that engine before.

 

Well folks- now I know where it comes from.

 

The 1981 Cadillac.    Yes sir re bob, back in 1981, GM came up with a special engine for the Cadillac that year.  One of the first varible cylinder engines, the "V8-6-4" engine was a 6.0 LITER 368 cubic inch engine alright.  It only lasted one year, then was replaced with a bad engine.  But for one shining moment, it was out there.

 

Take a look at this write up:

http://www.mcsmk8.com/8-6-4/8-6-4.HTM

 

 

Looks like GM dusted off the old design, made it a flex fuel engine, and hooked it up to a hybred to make it a new, 2010 model.

 

 

 

 

Just because it shares the same displacement doesn't mean it has anything to do with the old Cadillac V-4-6-8 other than the concept. The Cad 6.0 closed intake valves, which caused it to suck oil into those cyls causing problems when they were reactivated. The 82 Cad 6.0 was the same engine with valve covers that didn't have the rocker arm deactivaing solenoids, 4 deactivating intake rockers, wiring or control program, otherwise it was the same engine. Both versions were based on the Cad engine of the day.

 

The current Active fuel management thanks to port fuel injection just shuts off the injector to the cyl not in use. It has been around for a couple of years now. It also varies which cyl is not fired to keep all cyls "hot" and ready to fire when all are needed. It is the same basic current generation small block.

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EMAS- so the current variable displacement forces compression on a non-firing cylinder? 

 

Or is some valvetrain action in place to prevent such negative work?

( I realize that w/o fuel these pressures do not climb real high- still----)

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EMAS- so the current variable displacement forces compression on a non-firing cylinder? 

 

Or is some valvetrain action in place to prevent such negative work?

( I realize that w/o fuel these pressures do not climb real high- still----)

 

No valve train action is included, the compressing the air does result in some drag, but the compressed air does return some of that force on the

"power stroke".

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I don't see how the Prius being a FFV would make near as large as a dent as the Silverado. The Silverado uses much more fuel so the savings will be much larger, combined with the fact that the Silverado in general is a much higher volume vehicle and it makes an even larger dent in the use of fossil fuels. Of course that depends on the amount that GM actually produces and sells.

 

Yeah, big picture that is correct for sure. I had tunnel vision on that one thinking of "personal" usage  :D

 

 

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EMAS- so the current variable displacement forces compression on a non-firing cylinder? 

 

Or is some valvetrain action in place to prevent such negative work?

( I realize that w/o fuel these pressures do not climb real high- still----)

 

No valve train action is included, the compressing the air does result in some drag, but the compressed air does return some of that force on the

"power stroke".

 

Good point- and at least it should stay cleaner than an open exhaust or intake would leave it.

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It sounds like all of their truck certified versions of the 2010 SBC will be FFV so the Hybrid became a FFV by default since unlike some other hybrids the GM trucks don't use a dedicated engine. But on the other hand they're not showing the 6.0 in the regular trucks and not showing the Tahoe Hybrid as a FFV.

 

The Silverado XFE ties with the F-150 SFE in EPA city and highway fuel economy estimates. The Ford trucks are equipped with "fail safe" cooling where they limit max power output and alternately  de-activate 1/2 of the cylinders making the engine "air cooled". So the Ford does have cylinder management programing in those vehicles, they just don't use it in the same manner.

 

When you consider that any given vehicle will have a set power requirement to move it during a specific situation, on the face of  it is hard to tell if it is an advantage or not is hard to tell. Aparently GM thinks ie does while Ford doesn't.

 

A given vehicle will require a set amount of power to cruise at a given speed. So the question becomes how the main factors involved balance out. The frictional losses of a cylinder remain even if it is inactive. Keeping the valves working as normal in effect turns the cylinder into an air spring but certainly the frictional losses remain. On the other side having 1/2 the cylinders inactive means that the amount of air the engine will pump must go to allow the same power generation with 1/2 as many cyls, that means larger throttle opening . The larger throttle opening means lower vacuum and thus less loss due to that friction (one of the reasons a diesel engine is more efficient, the engine doesn't have the friction of making vacuum). Increasing the throttle opening means that the VE or amount of air ingested per cyl goes up raising the effective CR and thus the efficiency.

 

So the question in my mind is it just marketing hype, with little to no fuel efficiency benefit? If it isn't just hype why does the GM full size pickup w/AFM tie the Ford w/o and both beat the the Toyota w/o which beats the Dodge w/?

 

Steve-O, yes the perspective you look at it from makes a world of difference. From the standpoint of how little fossil fuel can be used by a vehicle a FFV Prius would be the hands down winner. From the other perspective how much fossil fuel would be prevented from being used by the Silverado FFV Hybrid? From yet another perspective how much more demand for E85 would be generated by the Silverado? In all cases assuming similar annual vehicle mileage, access to and actual % E85 fill?

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With the addition of an extra battery pack(making it a PHEV), the Silverado may have a

 

shot at up to 30 mpg city. This would be limited range and much extra cost, but an

 

interesting  way to nudge  the industry to try something new.

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