Mitsubishi rarely mentioned from the 80's ? (Variable displacement / VVT)

[DIMS]

Mitsubishi made an engine coded 4G12 I think it was the first to feature some form of variable displacement. (Modulated Displacement) technology,

I remember this from a magazine I read many years ago but I could never find it again.

Mitsubishi had a 4 cylinder engine that de-actived cylinders. I think it got something like 60MPG at 50MPH and had 115HP? I cannot seem to find any data on Fuel economy or HP...or anything for that matter so maybe I'm on stale meds & this was just a dream?? I'm going to keep looking though


I did find thid too! Variable valve timing with MD!
Displacement on Demand
In 1993 MMC developed its own variable valve timing (VVT) called Mitsubishi Innovative Valve Timing Electronic Control (MIVEC) with the MD variant. The revived MD technology was now in its second generation with improved electronic engine controls enabling the switch from 4 to 2 cylinders, which reduces the energy wasted due to pumping losses. In addition, power loss due to engine friction is also reduced. However, the final conclusions were that the major gain in fuel economy was the VVT system not from the MD feature and it was dropped in 1996.

[Frank Lee]

Somehow I missed this and didn't find out until today that there ever was a production 4 cylinder variable displacement engine. Perhaps as they alluded to the 4-bangers are already under enough load such that reducing the cylinder count further doesn't help fe enough to justify the added cost and complexity.

[Cobb]

I knew they had a lean burn for idle purposes of a 23 to 1 ratio, but not about the cylinder thing. What little I know about them is they can produce power and those vehicles require 93 octane.

Now honda does something funky on their insight and hch where it runs on 3 cylinders or turns off 3 cylinders at idle. I am not sure how to really test this, but if you idle an insight with no load when warmed up it sounds like a singer sewing machine. You walk around back and it sounds like a geo metro hitting on 2 cylinders.

Pop the ac on and it starts to idle like a tradational 4 banger and likewise it sounds like it around back.

Cant speak for the newer, but the older gen insight pulsed the ima rotor to even out the idle of its 3 banger engine.

[Miller88]

VCM on Hondas just shuts off one bank of cylinders during part throttle cruise. It does have slight MPG gains, but, apparently it eats motor mounts and causes the head that is not deactivated to sludge up and destroys the camshaft.

Until I started reading up on the Mirage and Mitsubishi in general, I never knew how much innovation they had over the years. Early player in VVT and GDI.

[xecute]

The Mitsubishi Colt/Mirage 1410 cc variant certainly did feature "modulated displacement" technology, a form of variable displacement.


It worked okay, but according to Hitori Yoshi in a Wheels Magazine drive report in Feb 1982, it had very long throttle movements under 2 cylinder mode, and felt pretty rough. The economy figures are Imperial mpg.

Like a lot of things, Mitsubishi was well ahead of the pack. The Sirius Dash 12 valve Starion Turbo engine with variable valve actuation was another

[niky]

We get a lot of their GDI cars surplus.

Fascinating machines. It's sad that Mitsubishi is no longer the innovator it was in the 80's and 90's. The Mirage is certainly fascinating from a technical point of view, though... hopefully the new Lancer (which is supposed to be smaller and lighter) will follow in those footsteps.

[Daox]

VW currently has a 1.4L TSI (turbocharged spark ignition) engine with cylinder deactivation. The mpg gains are pretty big.

http://ecomodder.com/forum/showthrea...ion-20943.html

[user removed]

I think Porsche and a lot of other manufacturers of both cars and motorcycles were paying royalties to Mitusbishi for their counterbalance shaft design. Same company built the Zero in WW2. My GZ250 has a counterbalance shaft. very smooth single cylinder engine.

regards
Mech

[ecomodded]

Originally Posted by Cobb

Now honda does something funky on their insight and hch where it runs on 3 cylinders or turns off 3 cylinders at idle. I am not sure how to really test this, but if you idle an insight with no load when warmed up it sounds like a singer sewing machine. You walk around back and it sounds like a geo metro hitting on 2 cylinders.

I have an idea for testing which cylinders deactivate
If you have a timing gun you could hook it up to the spark plug wires until you find the active cylinders or inactive cylinders during idle.

[cRiPpLe_rOoStEr]

Mitsubishi had been a leader in technology development but was not so effective in the marketing as were Honda and Toyota.

Originally Posted by Daox

VW currently has a 1.4L TSI (turbocharged spark ignition) engine with cylinder deactivation.

In my country this engine only comes mated to a DSG and with start-stop. Not sure if it also has the cylinder deactivation.