Running on 2 cylinders (alternating) at cruising speed... doable?

[deevergote]

Ok, here's an idea I came up with...

Back in the day, Cadillac had a V8 that simply stopped fuel and spark to 4 cylinders at cruising speed. Basically, when you didn't need the V8 power, you were getting 4 cylinder fuel economy.

I don't know how well that concept would translate to a 4 cylinder, but I figure it's worth a try!

Would it be possible to cut fuel and spark to 2 cylinders at a certain speed and throttle position? I would think alternating the cylinders doing the work would be a way to ensure even wear.

If it's doable with the software we have availible, the only concern I would have would be balancing issues. A V8 running on half the cylinders would be a bit more balanced than a 4 doing the same, I would think...




Regardless, would it work? Could it be done? Using throttle position and vehicle speed, would it be doable (and safe?) to run only 2 cylinders at a time?

[starchland]

cool idea.

Technicalities of the engine aside, would the engine make enough power running on 2 cylinders to overcome drag at 60 mph? I think not.

[deevergote]

Eh, it can roll easily enough... if it struggles, you can give enough throttle to activate the other two cylinders. Maybe. I'm not very knowledgable when it comes to tuning, so I have no idea how to implement these ideas

I'm also in NJ, the southern part of the state... where it's flat as a board. It would probably work for me. Perhaps not as well on hilly roads.

[MadSpleen85]

Imagine the gas mileage we would get on two cylinders.... NICE. Good Idea just need someone to figure out how to do this safely. Keep us posted. Later

[HondaGuy1212]

thats a really good Idea Mike but I think that our 4 cylinders get good enough gas mileage but If its possible that would be sweet

[d112crzy]

you could make a switch to enable and disable it.

it wouldnt so much have to do it at a certain speed, but more at whenever you need/want it. kinda like CC.

anyways, im sure fuel could be cut off easily by tapping into the injector wiring and making a switch for that, but im not sure about the ignition. maybe its the same?

[deevergote]

Just tap into the ignition wire!

I bet MSD has something that could be set up that way...


A non-computerized switch might be the easiest way, you're right.


The only thing with that is that it would kill off 2 cylinders completely. If I could find a way to make it computerized, all 4 cylinders could be used, just not at the same time.

[d112crzy]

well now you're just getting to complicated, at least of us DIY'ers. Im SURE that its possible, it would just require some ecu coding.

[kmart64]

well 3 cylinders should be okay then....the new impalas have v8's that I believe can switch down to 4 cylinders, and later, even 3.

[d112crzy]

just pull your plug wires, lol!!

[N9netwoAccord]

maybe i'm talking out of my ass here but just a suggestion/guess... what if you use something with an MSD ignition or whatever like use the guts or circuit board or whatever it is for the launch control or whatever to cut off spark and fuel for a lower RPM or something if thats even possible? I don't know just a thought

[NorcoAccord]

Would it be possible to cut fuel and spark to 2 cylinders at a certain speed and throttle position? I would think alternating the cylinders doing the work would be a way to ensure even wear.

If it's doable with the software we have availible, the only concern I would have would be balancing issues. A V8 running on half the cylinders would be a bit more balanced than a 4 doing the same, I would think...

Regardless, would it work? Could it be done? Using throttle position and vehicle speed, would it be doable (and safe?) to run only 2 cylinders at a time?

Well I would think you would want to activate it when you clicked on cruses control that way once your at freeway speed i would think it would be no problem, as long as you don’t plan accelerating anytime soon, and then if you could pair that with an overdrive so that you could get the rpm at 1500 or 2000 and even less. I think it is possible but how feasible would it be, you would want to run it off a laptop using some tuning device to control spark and fuel. The only question is how feasible is it, and would the 2 cylinders your running on would they require more fuel or any special characteristic. Going back to what deevergote said about even were you would want the computer to have a limiter say in miles or hours before the 1st set of cylinders would re-activate and the 2nd set of cylinder would de-activate so that wear patterns would be even.
If you did plan on doing this you would want to figure out which cylinders you want to fire, like 1 and 4, or 2 and 3, 3 and 1….etc.
I don’t know a lot about cars but those would be some of the issues I can see you would be asking along with when you perfect who would you sell it to and what would be the price of this powerful information.

[TheNextEpisode]

Just pulling the spark plug wires or preventing the spark from occuring alone wouldn't be enough though. I mean we're trying to save fuel, not battery power. I suppose as long as fuel flow could be prevented from which ever two cylinders aren't firing, then the spark plugs on all four cylinders could keep firing away.

Correct me if I'm wrong though. Sporting a 2-banger would be pretty cool. I wonder what kind of exhaust note you would get on that...

[sackingz123]

thats a really good Idea Mike but I think that our 4 cylinders get good enough gas mileage but If its possible that would be sweet

i like that pic of ur car....

[sandman61377]

Just pulling the spark plug wires or preventing the spark from occuring alone wouldn't be enough though. I mean we're trying to save fuel, not battery power. I suppose as long as fuel flow could be prevented from which ever two cylinders aren't firing, then the spark plugs on all four cylinders could keep firing away.

Correct me if I'm wrong though. Sporting a 2-banger would be pretty cool. I wonder what kind of exhaust note you would get on that...

Probably sound like an Insight at cruising speeds. Isn't the gas engine in those a 2- or 3-cylinder motorcycle engine? The electric motors in that shut off when you reach cruising speed, so the 4-cyl on 2 should be able to continue its foward motion without problem just like the Insight, although our CB's weigh a sight more than and Insight. Mataining speed takes alot less power than accelerating.
Wouldn't cutting off the injectors for two of the cylinders ensure no gas was beeing wasted going to the two that weren't running?