Hemi v8 concept on Lexus v8

[Boeta Mac]

Is anybody familiar with the concept the Hemi v8 uses where it disables a few cylinders on cruising or when all power isnt required?

What actually happens to disable these few cylinders?

The reason in asking is that if i can incorporate a similar feature, the Lexus v8 can be more economical??

The Perfect Power management im fitting to my 7m for my d/c hilux 4X2 can somehow do sumthing similar.....

Any ideas????

[Mud Dog]

Don't think it's a worthwhile exercise, Llewellyn .... can get a bit complicated. One would have to have two separate ignition systems configured over the cylinders in such a way that the motor will still run smoothly / balanced on the 'main' system ... then the control of the injectors needs to be 'cut' for the unused cylinders. You would also need to have decompression valves to be activated on those cylinders, otherwise you would be losing a lot of power to overcome the compression on them.

I think that ideally something like this should already be incorporated into the original design of the motor.

[hilex08]

Dont wanna be ignorant, but why cut off cylinders when you can utilize that glorious V8 to its full potential, at all times.

Might as well fit a 4 Cyl from the start??

[ChrisF]

Definately the future of high performance engines.

SADLY a LOT of time is spent in traffic where the max is not needed - then idle along. and have a very economical engine.

when you "put foot" you HAVE all the power ... :)

[Mud Dog]

Probably just a matter of time until someone comes up with the idea (oops, someone just did) of two separate motors integrated into the same block, but each with it's own crank ... the two cranks married together with a torque converter before the clutch so that there is no drag at all from the idle motor if you're only running on one side.

I think it could work.

[Mud Dog]

Imagine the torque from two 4Y equivalents, side by side!

[ChrisF]

Andy that reminds me of the guy that put TWO GTi motors in a CITI golf - one in the front, and another driving the rear wheels.

Now THIS could make a nice 4x4 driving concept ..... Off cource with some DECENT motors ...

[Mud Dog]

I'm sure it would work .... IIRC the Bugatti Veyron utilizes that principle, but I'd prefer to be able to select 4x4 when I wanted it, regardless of whether I was running on ½ or full power.

[mark watson]

can be done but you will have to run 2 throttle bodies one for each bank and shut the one down as for the rest just switch the power to that bank of injectors off , leave the spark as it wont do anything.
by closing the 1 throttlr the 4 cylinders wont run as a compressor and sap the motor of power.
wiki the 1gz fe v12 toy motor they can shut a bank down.

[MOFASA]

Why bother to fit it to a different motor???

Just fit the HEMI and you'll have a MONSTER on your hands

[kfxnando]

just go right ahead and get a Hemi Jeep!!! they are great fun!!

jokes aside, as far as I know all new EFI motors shut off the injectors when throttle is closed, like when slowing down or on a downhill with the foot off the throttle!!
its a fuel saving measure!!

although not half the cylinders when standing at the lights!!