Cylinder deactivation - V6

[SomptingGuy]

Has anyone worked on this? If so, are there any examples out there where the full firing order isn't alternating bank-to-bank? I.e. by deactivating one bank, firing becomes uneven.

 

[GregLocock]

OK, I'm astonished. Also, as it happens, the Bosch blue book disagrees.

You have posted 1L 1R 2L 2R 3L 3R

Bosch says 1L 2L 2R 3R 1R 3L or
1L 1R 2R 3R 2L 3L


Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[mishar]

To avoid all kind of misunderstandings with different numbering I spent some time on that animation.

That order of firing is used by: GM, Ford, Chrysler, Toyota/Lexus, Honda/Acura, Nissan/Infiniti, Mercedes, VW/Audi …

Order you posted is possible, but I did not find anybody using it. Probably because all cylinders from each bank are firing sequentially, creating totally uneven firing order per bank. It would sound definitely like Harley when both banks are working. Shutting one of them off would be ridiculous. Not sure about intake and exhaust resonance either.

 

[SomptingGuy]

For the record...

I first went to my Bosch blue book to check the firing order and found neither of the two "Normal" firing orders matched it. Suspicious, I asked some of our analysts and got more variations (including the 1L 1R 2L 2R 3L 3R order which I also didn't expect).

Turns out the customer simply got his order wrong. However I've learned from it so the day wasn't entirely wasted.

 

[GregLocock]

So the mystery piles on.

Admittedly a properly designed V6 has a short crank, so perhaps suppression of the first torsional is not the top priority.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[SomptingGuy]

I did run the model and it did sound remarkably like a Harley (the exhaust at least). I know that HD have some kind of patent or something on that sound, so I guess a odd-firing 3-cylinder like this would be in breach of it??

 

[globi5]

NickE,

not on topic but just for clarification: A Series Hybrid as opposed to a Parallel Hybrid works. On average a Prius might need less than 20 kW to drive on a highway.
Since lag is irrelevant in this application, the gen-set can also be a gas turbine, a stirling engine or a tiny piston or rotary engine with a comparitively large turbo-charger.

http://www.autoworld.com/news/GMC/Series_Hybrid.htm

http://www.p2pays.org/ref/16/15287.pdf

It might not work if one wanted to drive at 120 mph continously, which is however a very rare and mostly illegal scenario. Also, there's not much reason in pulling an additional gen-set behind a Prius, as the Prius already has a relatively small IC engine, a CVT and the ability to turn of the IC engine at any time and it can therefore reduce pumping losses to a minimum as is.

A Series Hybrid might make sense for an electric car such as the Tesla Roadster in order to reduce the weight of the heavy battery pack.