Aug 28

BREAKING: Volt Combustion Engine Still Undecided: Won’t be HCCI at First

 

tom_stephens.jpg
Tom Stephens, GM VP Global Powertrain

As we mentioned in a previous post, GM recently demonstrated an HCCI engine for the first time in a driveable car. The technology; good at low fixed RPMs, very fuel efficient, seemed ideal for the Volt’s on-board generator and we discussed that possibility.

I had the opportunity to pose this question to Tom Stephens, who is General Motor’s Group Vice President of Global Powertrain and Global Quality.

Mr. Stephen’s is highly involved and interested in the development of HCCI, and the ideal person to tell us about it’s applicability to the Volt.

Here is the conversation:

GM-Volt: “Is this engine type (HCCI) being considered for the Chevy Volt?”

Mr: Stephens: “HCCI is a technology that is just emerging from the laboratory and won’t be ready for production when the Chevy Volt is introduced. However, when HCCI is ready for production, the Volt would be one of the many applications under consideration. ”

GM-Volt: “Are you aware of which engine that will make the first gen Volt, or is this still under discussion?”

Mr. Stephens: “The engine for the Chevy Volt is still under discussion.”

Overall, my feeling about this exchange was very positive. Coming from a man in his position, there was a very clear sense that the Volt is being produced, and the HCCI engine was even too new technology for it. Obviously, GM does not want to hold up the Volt’s production one iota.

Also it is clear that GM engineers still have more work to do in figuring out exactly what type and configuration of combustion engine will be best for this car. Bring on the mules.

This entry was posted on Tuesday, August 28th, 2007 at 9:57 am and is filed under Design, Engineering. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

COMMENTS: 14


  1. 1
    kent beuchert

     

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    Aug 28th, 2007 (10:03 am)

    I assume that cost is the driving force behind the selection of the range extender
    engine, since exactly how long it takes to
    recharge to the desired level seems rather
    insignificant. I wonder if turbocharging is
    also iffy? That does cost extra.


  2. 2
    Tim

     

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    Aug 28th, 2007 (10:08 am)

    “Obviously, GM does not want to hold up the Volt’s production one iota.”

    I also believe this to be the case and I hope that they keep this vision clear.


  3. 3
    Matt986

     

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    Aug 28th, 2007 (12:16 pm)

    I’d also suspect that it might be more difficult to induce the HCCI cycle under heavy load.

    As I understand how HCCI works (I understand quite well what compression ignition is, and thus how HCCI purposely induces this condition, whereas almost all ICEs try to avoid it), it works under low loads, like when you’re cruising on the highway and your engine is under very light load.

    Maybe it’s possible to have the Volt’s engine kick in a full power to generate a lot of power, then lower it’s output and go into HCCI to provide a gentler ‘topping off’ of the battery?

    We’ll see, there are definitely lots of possibilities for the generator and the E-Flex system.


  4. 4
    Questions

     

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    Aug 28th, 2007 (2:19 pm)

    I appreciate your enthusiasm and work in this area. I am very curious about this car, and I want it to succeed.


  5. 5
    Jim

     

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    Aug 28th, 2007 (3:41 pm)

    What a great find to happen on your site while doing a little EV web-surfing! I’m hooked on the lastest on the Volt. My current EV is a converted Porsche 914 but I’m pulling for some American company to finally get their head out of the sand (or other appropriately dark place) and take a chance on a new direction. It is obvious that the current direction and status quo have resulted in reduced market share and a bleak outlook! I might actually buy American again with the Volt! Thanks for a great website!


  6. 6
    omegaman66

     

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    Aug 28th, 2007 (3:52 pm)

    I imagine the cost of the battery will be a changing figure over the next decade or more. But the cost of the generator should be fairly predictable considering the ice engine has been around for a long time.

    Just forward thinking here. Wondering how much the cost of the car will come from the generator. Not for everyone but a non-vacation commuter car doesn’t need a generator if battery powered driving distance can be expanded a bit to give people a good cushion on range for the 330 days a year those in the south need an AC and for lights and other accessories.


  7. 7
    Andy

     

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    Aug 28th, 2007 (3:52 pm)

    Breaking: Nothing new! (sorry, I couldn’t resist… Lyle you do a great job)


  8. 8
    Russ Judge

     

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    Aug 28th, 2007 (8:18 pm)

    I would like to know what kind of electronic drive the volt will have ie AC or DC. Will it have the capability to act as a generator, to pump 120v/60Hz back into your house as a backup generator


  9. 9
    Lyle

     

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    Aug 28th, 2007 (8:29 pm)

    [quote comment="5414"]Breaking: Nothing new! (sorry, I couldn’t resist… Lyle you do a great job)[/quote]
    Yeah I guess you’re right..in the world of Volt news even the fact that no decision has been made on something is still news to me.


  10. 10
    Brian

     

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    Aug 28th, 2007 (9:28 pm)

    [quote comment="5425"]I would like to know what kind of electronic drive the volt will have ie AC or DC. Will it have the capability to act as a generator, to pump 120v/60Hz back into your house as a backup generator[/quote]

    The motor will certainly be AC (either induction or permanent magnet, probably PM I think).

    DC motors are not efficient enough, although they could save some money on the electronics side.


  11. 11
    Drake

     

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    Aug 28th, 2007 (10:02 pm)

    This is totally off topic, but a pipe dream I have for the Volt is to be able to log in to its onboard computer, wirelessly like you can with a network router or a high-end copier.

    Once logged in, you could run reports covering a wide range of areas like efficiency, average mileage, gasoline usage, upcoming servicing needed, etc. While logged in, you would also be able to upload mp3s and playlists to the car to listen to while driving. You could also configure what time of day you want the batteries to charge, and you could even program what time of day you wanted the heater/air conditioning to come on so that each morning you had a warm/cool car. This would be especially nice in the winter. Plus, the electricity to do this would still be coming from the plug so it would not affect the battery’s charge for your day of driving. This feature would probably not activate if the user didn’t/forgot to plug in and might be limited to a maximum of 10 minutes or so before turning off the air conditioner/heater.


  12. 12
    Dave

     

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    Aug 29th, 2007 (7:11 am)

    Russ Judge says: “I would like to know what kind of electronic drive the volt will have ie AC or DC. Will it have the capability to act as a generator, to pump 120v/60Hz back into your house as a backup generator”

    Russ – see forum thread here:
    http://www.gm-volt.com/volt-discussion?forum=1&topic=50&page=1

    Brian – Yes most generators are mechanically AC, but the generator includes diodes that change that into a choppy DC which connects to the battery. See pictures here:
    http://www.bcae1.com/charging.htm
    (about 1/2 way down the page).

    So the best way generate 120 volt AC power is to connect an Inverter to the battery and let the gas engine generator charge battery as necessary.

    Inverters aren’t that expensive. The only issue is that the Li/Ion battery in the Volt is a much higher voltage than a regular 12V car battery, and the Inverter would need to be designed for this. So it might be a while before aftermarket Inverters for the Volt are available. This is why it would be great if GM offered this as a factory option…


  13. 13
    Dave

     

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    Aug 29th, 2007 (7:34 am)

    Drake – I agree, it would be great if you could trigger the climate control system of your car wirelessly while you are plugged in. It would also be great to able to do the other things you mention.

    But for the average Joe, my concern is that these features may be confusing and/or frustrating. Also, a lot of folks are turned off by any kind of geek factor.

    So, I think these features should be added in such a way as to be hidden from the average user. Perhaps this could be offered as an option. Or better yet – offer an optional in-dash navigation system, and have these features enabled further down in the menus of this unit.


  14. 14
    Russ Judge

     

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    Aug 29th, 2007 (8:11 am)

    Has GM given any thought to using a stirling engine to power the volt’s generator? The stirling would appear to be an excellent match for the volt. It is the world’s most efficient combustion engine and is completely silent. It has very poor power response but this would not be a factor in powering the volt. It is not an unknown factor as the Swedes actually use them in powering some of their submarines. I seem to remember GM once actually looking at them.