Audi Engine with Dynamic Cylinder Deactivation & Integrated Headers
 

This is promising:

Green Car Congress: Audi A3 launching with new 4-cylinder engines; cylinder-on-demand, supplementary indirect injection, start-stop and modular efficiency technologies

http://bioage.typepad.com/.a/6a00d83...c7dc970c-800wi
http://bioage.typepad.com/.a/6a00d83...b1cf970b-800wi

(My apologies if this has already been posted.)

I'm out of the loop, but are VW and Audi still connected at the hip?

If so, the cylinder deactivation might be the same as here: http://ecomodder.com/forum/showthrea...ion-20943.html

yet more complicated ICEs..the integration of the exhaust manifold into the head and the required water cooling of the aluminum exhaust seems a disaster waiting to happen, oh about at 75k miles when the water pump goes out and not just a head gasket failure, but literal engine meltdown. Must be a safer way to heat up the engine faster?

The more they try to improve the ICE, the more electric cars become appealing.

VW and Audi are more than "joined at the hip". VW bought Auto Union in 1964, which had owned the Audi brand name since 1932 (tho no cars had been produced under that name since the thirties). Virtually every Audi on the road today is 100% VW.

The sliding cam-sleeve mechanism appears to be exactly the same.

They're fully connected.
Using an identical engine line-up, the same platforms, the same parts, the same accessories.

Just the cosmetics, price and marketing are different.

Yeah.

I hope they'll also combine this technology with CNG.

Is that integrated manifold (and associated cooling) going to mean - or enable - putting the exhaust catalyst directly at the collector instead of under the car?

I'm guessing that could help with packaging.

Personally I think they are going in the right direction with the integrated exhaust manifold. I think they should go even further and get some of that exhaust heat in the intake manifold as well as eliminate the head gasket as was done decades ago.

With a single casting consisting of the intake, exhaust, and cylinder walls combined with the head you would never see any gasket failures in those most prone areas.

While I understand the principles involved with cylinder disabling, why not just have two 2 cylinder engines capable of working independently or together. I think Ford ecoboost 3 cylinder may be a better compromise unless aero drag is reduced to the point where two cylinders would do the job up to about 75MPH, but then you could also reduce the displacement of the 3 cylinder.

What I don't like is the pistons still reciprocating as well as the upper half of the rods as well as the imbalance of two cylinders subject to combustion heat dissipation and two that are not.

regards
Mech

I think the cost/complexity of making multi engines sync and/or the objectionable NVH of running them out of sync hurts that concept.

Come on Frank. Mazda is using a start stop system that stops the crank at a specific position and restarts the engine with compression only. That's some very precise positioning, and the engine does not naturally stop just after TDC compression stroke.

Coupling to two cylinder engines in one position would not be difficult at all, if they even needed to be coupled at a specific crank position. As long as they are independently balanced I don't see the necessity for any specific coupling position.

Of course if they were pressurizing a hydraulic accumulator there would be no issue with connection whatsoever.

regards
Mech