Don't get me wrong, this is not a problem. I had this I dea by watching nhra nationals. You know the way they seem to just cancel a cylionders when it goes out ( this is what it seems to me)or they shut them all at the end of the race, I wondered If we could do something alike to improve fuel economy when we don't need 8 cylinders. Here's is what I was thinking: when your on the highway( or maybe at a stop light) you would by some means cancel cylinder(s). I have no mechanical wisdom and don't pretend to have any. So would it be possible to wire a switch, maybe to the injectors, or something else, to shutdown cylinder(s)???

 

Sure, it could be done, either mechanically or electronically, but I don't think there would be any value added...

My thought would be that the non-fueled cylinders would still pump air out creating oxygen content in the exhaust...so then the other injectors would open longer to provide corect O2 sensor readings....effectively running the other cyclinders rich.

I guess you could set things up electronically to scale the O2 sensor readings by percentage based on how many cylinders are being fueled...

Didn't Cadillac do this in the 80's?

 

Cadillac has system that run on either 4, 6 or 12 cylinders depending of the need. I think I heard new hemi's would be equipped with it, but that is not the question.
Would there be a way to do this with a switch type mechanism (the question is really what would I need to do in order for it to work) ?? What is the easiest route?? I really think it could help lower fuel consumption.
For an instant I tought of shutting both intake and exhaust valve, but tought about the results( boom I think). I told you I don't have car mechanics knowledge

 

they already do this.

go lookup "displacement on demand" for the new GenIII motors.

in a nutshell its like this:
the computer opens a valve.. this valve routes oil pressure to the lifters, disengaging them. it also cuts fuel and spark to thoes cyls.....

its a option on the new GM trucks, and all of the new LS2/alum truck blocks have the bosses cast into them.... but unless the engine was ordered with it, its usually not machined in.

 

But would there be a way for me to do it on a camaro without buying one of those gen 3 motor. Could it be done with the motor there is in the 'maro? I'm relly looking to do this on my car as a way to save fuel, as I don't have much money. I was Thinking of a switch tah would activate/desactivate one or more cylinder(s) manually.So, is there an easy, or not too hard, way for me to do this to the actual motor ??

 

That's the problem I see as well.

And how would you close both the intake and exhaust valves on a motor like ours?

Just do a full tune-up and take your foot off the gas a bit..

 

For the valve thing, I said that I have no mechanical skills nor pretend to have so there no way I pretend I knew it could be done.

About the tune-up, I was talking of a car already tuned. Just searching for ways to improve gas mileage just so I can ride more often in the future camaro (yep I don't have a car yet).I'm 18 with a medium-good job but still, I would like my future car not to swallow all the money I have and to be able to ride when I want without worrying of my bank account going under.

I was basically just tossing an idea I had in mind.

 

its easy way its called buy a daily driver....if you wine about the gas mileage you shouldnt be driving a camaro with a v8, go buy a thirdgen with a 4banger in it...

 

He's not driving one yet

Oh and I'd be willing to bet that the gas money won't sink your bank account, it will only add to the money troubles you find yourself in when you decide your car isn't fast enough...well that's what's happening to me anyways.

 

Thanks for all your response, I don't think i'm whining (I may be wrong), I am just looking for my future car to be as efficient as it CAN be. I would not buy a 4gen for 2 reason: they cost more and I don't care about them. I love thirdgen( if you didn't knew it)

I think I can go a long way speedwise with a spicy carbureted 350. I know that more is better but it will be a good start.

Sorry to sound like a jerk (it seems I do). I just want to enjoy my future thirdgen as often as I would like witout thiking that much about money. It this is a crime, well I plead guilty.

 

A properly tuned stock TPI 3rd gen will get 24 to 26 MPG on the highway and a stock LS1 4th gen will get 26 to 28 MPG on the highway. You will not sigificantly increase (and may actually decrease) this already excellent fuel economy with what you are proposing.

 

Thanks

 

what if you ran 8 o2 sensors like ummm i forget what car that was, and shut off the readings from those cylinders as well as the fuel/spark? With gas prices what they are now it would still probably save money in the long run. Is this plausable with a custom computer?

 

Canning injectors will not help increasing mileage nearly as well as dropping fuel and closing of the valves to decrease the pumping losses.

GM shuts down both the intake and exhaust valves for this.(new DOD setups)

Doesnt have anything to do with anything else. 02 reads fine as is, the affected cylinders have no airflow, or fuel :-) Both valves are closed

A sweet idea realisiticly u need like 40hp in a thirdgen to do 60, so drop a few cylinder.

Retrofitting this in its entirety to a conventional small block would be a huge pia. Need more processor power than thirdgens are equipped with(might be doable if u can do your own code), but the oil passages would be the biggest killer. Ls1/smallblock roller lifters interchange, technically do the DOD lifters still fit? (I dont know this one)

Better off playing with the stock cal which has much to be improved upon and also activating the highway mode code and utilizing the patches that have been developed.

For the sake of the arguement I wont even talk about the original early 80's Caddie displacement on demand lol :-) junk anyone?

later
Jeremy

 

If you are really into saving gas and looking for ways to, just wait until ultra megasquirt comes out with it's sequential fuel injection. That can solve some of the highway mileage problems.

 

Sequential vs batch isnt where the mileage comes in at.

Sequential is more an emission benefit than anywhere else.

If everythign was perfect with each system on the same engine, you would prolly notice next to no increase in mileage or power.

It works real good for cutting cold start emissions however, and also with individual cyl timing, etc, etc(which doesnt apply to anything we can do in the near future)

later
Jeremy

 

wouldn't closing both the valves just make it harder for the crank to spin because there's no way to get ne air into or out of a cylinder so it's either trying to suck air in that it can't or constantly in a compression/depression cycle. Wouldn't it be easier on the engine to let air flow through and have free movement on atleast half the cycles?

 

If you're worried about highway mileage, just enable the Highway Fuel and Spark modes in the factory programming, and set your cruise AFR target at around 17:1. A 305 with TCC and 2.77/2.73 gears can do 30 MPG that way.