Idea for fuel economy???

[Billyisgr8]

So seeing that the new trucks shut off 4 cylinders to get high 27+ mpg, can we also do that to get 30+

I'll throw this out there, not sure if this would damage the pump, or not

Run a vacuum, and speed signaled switch, or just a toggle on the dash for simplistic sake.... to a 12 volt solenoid that would bleed off pressure with a oneway check valve that would open up at say 100psi to 2, 3, 5, 8 cylinders while cruising, This bleed would have to be t'd into the lines with a check valve on each line and could dump into the return fuel line back to the tank. The solenoid could be controlling all 4 lines into 1 manifold to make it simple.

 

[71cc]

Well, I have the hypermax aneroid "puff limiter" on my mind lately. It is basically a boost referenced fuel limiter. I want one, but they are $285 . I have read a 7.3 marine IP come with one. If I could adapt one or find one cheaper I would explore that option on my truck.You may can manipulate that thing externally to "trim" your fuel. It Since it takes X amount of fuel to run a certain rpm at steady state it might not work.

 

[69oiler]

i dont know about yours but my IDI needs all 8 cylinders just to get out of its own way.

with a diesel you can reduce fuel consumption just by lifting your right foot. i'd think if you eliminated fuel from cylinders, you would have to feed that fuel to the remaining cylinders in order to maintain speed.

also i think dead cylinders would result in a very rough running IDI.

 

[Billyisgr8]

yea, in the dodges when it cuts out some cylinders, it adds abit to the others from what I understand.

 

[Dsl_Dog_Treat]

Not to discourage any one from building a better mousetrap, but that would be extremely difficult to accomplish on these setups targeting individual injectors.

I think that letting off any more pressure than what the injector will hold after it pops off will cause a retarded fire on it's next cycle in attempts to get the static line pressure built back up.

The cheapest way is as Rob said, go easy on the go pedal.

On Mater I can get anywhere from 14 to 20 mpg depending how hard I push on the go pedal.

 

[Agnem]

I know some of the newer gas engines use this technique to run the engine without coolant (the non-powered cylinders become air conditioners I guess), but I didn't know they were actually killing the cylinders. Seems to me it would run rough. About the only thing along those lines that you could do to the IDI, would be to build something that would kill the FSV when your foot is off the pedal, and RPM's are above 600. That way, all your coasting would be completely free. I'm not sure, but I think the PSD does this.

 

[snicklas]

Mel,

You are correct about the "free" coasting. On my 6.0L in the X if I have enough momentum, I can hear the injectors go completely quiet. I have also had the transmission in Tow/Haul Mode (Torqshift 5 Speed) going down a steep grade and have gone a mile or two and not heard the injectors at all....... also makes for a decent "jake" brake....

 

[91f2504x4]

I would also think if you just shut fuel off to the same 4 cylinders for prolonged periods of time you would incure a lot of wear. I would think you would want to alternate what cylinders you were cutting off fuel too, for example cutting fuel to 1,3,5,7 and then 2,4,6,8 on the next ignition event. I toyed around with this idea when dealing with my gasoline engine that used to be in my truck using an aftermarket fuel injection system. It seems like it would be hard to do with a mechanical setup and it would almost need to be electronic to make it really feasible.

 

[Feed Bunk]

International had a tractor with a v8 diesel that ran on four cylinders then went to all 8 when it went under load. If I remember right it was the 1468. I dont know much about international tractors or how that one ran, but it was mechanical. Just thought Id through that out.

 

[Billyisgr8]

Intresting, I wonder how the pump was set up?

http://www.tractorshop.com/articles/ih.html

 

[91f2504x4]

International had a tractor with a v8 diesel that ran on four cylinders then went to all 8 when it went under load. If I remember right it was the 1468. I dont know much about international tractors or how that one ran, but it was mechanical. Just thought Id through that out.

1468 and 1568 were both this way but their pump was designed that way at the factory, it would be much harder for someone to modify a mechanical pump to do this than it would be to just change some programming on an electronic setup to do the same thing.

 

[DeepRoots]

I had an Dodge Aries that ran on half the cylinders half the time.....
hmm, I think that mighta been something else, cuz the milage sucked.