I was thinking the other night about how maybe Cummins could incorporate some sort of cylinder deactivation like dodge has with the 06' Hemis. Could this be done just by shutting fuel off to 3 cylinders when cruising the highway? Or is this impossible?

Just a thought

 

the 24 valve trucks have this feature if you get the dealer to enable it , only not for highway crusing , it is for warmup , it turns off 3 cylinders, i imagine the
new HPCR trucks can do it too.

 

They do do that on the hemi and chevy engines. They shut down the spark plug and valves to that cylinder (fuel injecter too) They alternate cylinders to fire every other stroke as the other shuts off. So basically 4 fire, then another 4. It works off of hydrolic lifters, and computers. they do have this on big 18 wheelers, it's called something like Displacement on Demand, only use the power when you use the go pedal. It would be nice to see on the cummins however requires the lifters to be bleed to keep from opening, and would most likely require some big work. It would def. be nice, however I'm leary of that technology. I'm getting good milage and shutting down a cylinder every now and then I dunno. I'm old school, if it ain't broken, don't fix it.

 

you could do it just by killing the 3 companion cylinders and alternating how they all fire with some computer programing. you don't need to colapse the lifters [and we have completely mechanical lifters so nothing to colapse] when they do kill cylinders on larger OTR truck engines, they don't do anything with the valves either. they all have mechanical lifters or mechanical rollers on the cams. no hydraulic lash adjusters on large truck engines yet...

 

If you don't do something with the valves you are going to be compressing the air in the non-used cylinders all of the time. I don't think that would be the right way to to it. Kind of defetes the purpose of saving fuel - running a useless air compressor.

 

actually the hemi's valves are held open not shut... don't know how they do it, but I read it in some chrysler tech stuff one day...