Hemi Cylinder Deactivation

[Curt@BMCPerformance]

Found this on Allpar: The Magnum and 300C will be the first modern production vehicles in North America to feature cylinder deactivation. The Multi Displacement System (MDS) seamlessly turns off the fuel consumption in four cylinders of the 5.7-liter HEMI engine when V-8 power is not needed. This provides a world class combination of performance and fuel economy.The Chrysler Group MDS seamlessly alternates between smooth, high fuel economy four-cylinder mode when less power is needed, and V-8 mode when more power is in demand. In short, owners of the Chrysler 300C and Dodge Magnum RT will receive the powerful benefit of the Hemi engine with the fuel economy that they would only expect from a smaller, less powerful engine.

"The MDS was part of the engine's original design," said Bob Lee, Vice President Powertrain Product Team, Chrysler Group. "This resulted in a cylinder-deactivation system that is elegantly simple and completely integrated into the engine design. The benefits are fewer parts, maximum reliability and lower cost."

This system should triumph where the Cadillac 4-6-8 failed because of the speed of modern electronic controls, the sophistication of the algorithms controlling the systems, and the use of electronic throttle control. The HEMI will be able to transition from eight cylinders to four in 40 milliseconds (0.04 seconds).

The HEMI engine with MDS has completed over 6.5 million customer-equivalent miles through Chrysler Group’s development and durability testing.

The system deactivates the valve lifters. This keeps the valves in four cylinders closed, and there is no combustion. In addition to stopping combustion, energy is not lost by pumping air through these cylinders.

Customers will experience estimated fuel economy gains of up to 20 percent under various driving conditions, and a projected 10 percent aggregate improvement. Improved fuel economy is realized without any change in customer experience—drivers will receive the benefit without changing their driving habits and without compromising style, comfort or convenience.

[J4000]

Sounds good to me! Here's hoping it works perfectly. The last thing we need is a 4-6-8 situation. The fact that the system was designed into the Hemi in the beginning settles my nerves quite a bit.

[Curt@BMCPerformance]

lol technically doesnt it make it the worlds first 4 cylidner hemi....

[TehKing]

lol technically doesnt it make it the worlds first 4 cylidner hemi....

No.

Many, many engines have had hemispherical combustion chambers, including 4 cylinders. Two 4 cylinders of note that had them were the engine offered in the Mitsubishi Mighty Max/ Dodge D50 pickup, and the 2.3L in the Ford Ranger.

[Curt@BMCPerformance]

so is it still considered a hemi?

[TehKing]

so is it still considered a hemi?

"Hemi" is just short for hemispherical, the shape of the combustion chamber on the particular engine.

[Curt@BMCPerformance]

i know that but HEMI is a registerd trademark

[Justin33]

lol Mav, what the hell are you talking about now...

[TehKing]

i know that but HEMI is a registerd trademark

The word is trademarked, so what? I could trademark Poopsicle if I wanted to.

[DMAG]

i know that but HEMI is a registerd trademark

The word is trademarked, so what? I could trademark Poopsicle if I wanted to.

Sorry Matt, right after your post I trademarked "Poopsicle"

Copyright 2004 Poopsicle

[TehKing]

i know that but HEMI is a registerd trademark

The word is trademarked, so what? I could trademark Poopsicle if I wanted to.

Sorry Matt, right after your post I trademarked "Poopsicle"

Copyright 2004 Poopsicle

Darn you!

:D

[IS300M]

lol technically doesnt it make it the worlds first 4 cylidner hemi....

No.

Many, many engines have had hemispherical combustion chambers, including 4 cylinders. Two 4 cylinders of note that had them were the engine offered in the Mitsubishi Mighty Max/ Dodge D50 pickup, and the 2.3L in the Ford Ranger.

So wait, my 1997 Ranger XLT has a 2.3L Hemi?

[TehKing]

lol technically doesnt it make it the worlds first 4 cylidner hemi....

No.

Many, many engines have had hemispherical combustion chambers, including 4 cylinders. Two 4 cylinders of note that had them were the engine offered in the Mitsubishi Mighty Max/ Dodge D50 pickup, and the 2.3L in the Ford Ranger.

So wait, my 1997 Ranger XLT has a 2.3L Hemi?

No, by that time the engine design had changed.

The early 2.3L's were hemi's. The new design offered better fuel economy, more power and cleaner emissions.

[ximkolo]

i thought gm had done it already, at least that is what they said at the auto show, i think,

[FreeLantz]

Another link from All-Par... here is a very good and positive review of the HEMI from Popular Hotrodding. http://www.popularhotrodding.com/tech/0403phr_hemi/