OT?: New cars run on partial cylinders?

I'm guessing you've never seen a Cadillac V-8-6-4 ?

Well, that came out 25 model years ago... and didn't last very long.

Check this overview:

Rob

That was the mechanical contraption from the medieval ages.

Honda has been running multiple valve trains for several years as part of their VTEC series, with low RPM and high RPM cam lobes engaged via hydraulics.

In the Honda Accord Hybrid, the rear three cylinders are shut off during certain conditions by stopping the valves. Same with all four cylinders of the Honda Civic Hybrid.

Some GM SUVs have similar shutdowns.

In the trade we used to call it the 3-5-7.... Most (if not all) had the displacement modulation devices disabled at one time or another.

Not knowing anything about the engine, I can still offer opinions...

I'm unsure of how Cadillac handled the valve train on their old modulated displacement effort... I do know there were solenoids mounted under the valve covers, but that's about it.

With the current state of the art regarding engine controls, a workable modulated displacement engine is getting pretty close to "do-able", though I would have reservations about longevity.

One of the benefits of the much touted 42 volt system (that is always promised but never delivered), would be solenoids powerful enough to operate poppet valves (like the intake and exhaust valves in our motors). So, this mystery auto maker may have a 42 volt system on the go.... or, they may be using techology from HEUI diesel engines. The Ford PowerStroke diesels utilize high voltage for injector operation... the old 7.3 works at 115 volts supplied to the injectors and the 6.0 uses 48 volts to the same end.

There is no end to some of the amazing things that have been tried with the infernal (sp) combustion engine. In the early 80s, Ford had bought the rights to the "poly-motor".... built largely of space age plastics, this 4 cylinder twin overhead cam engine weighed something like 175 pounds and delivered (IIRC) 170 horsepower. Ford Motorsports was also hinting of a ceramic pistoned 1.6 litre four cylinder.... bragging about (again IIRC)

700+ horsepower.

I recall an article on a SAAB engine... I can't recall if the goal was modulated displacement or modulated compression ratios. The engine was built similar to the old Offenhauser engines.... the cylinder was cast as part of the head. In the SAAB effort, the position of the cylinder head was raised and lowered in relation to the crankshaft.

Even back in the late 50 and early 60s, manufacturers were experimenting.... Chrysler with it's free psiton gas turbine.

Much of the groundwork, though, has been laid out by independants.... Smokey Yunick (God rest his soul - he's kind of a personal hero) spent quite some time developing his "stratified charge" system... This engine utilized a turbocharger.. but not as a power adder. It was used to "homogenize" the intake charge which was, as I recall, a very lean mixture.

When it comes to the internal combustion motor... if you can dream it, there is probably someone playing with one in his "secret garage". Thanks for being a captive audience.

Yeah, one of Chryslers cars is designed to do this, the 300M I believe (someone correct me if I am wrong). V8 engine designed to run on only 4 cylinders when it needs to. Not sure how it is done. But I've read a few articles and a buddy who owns one was telling me this.

Sharky

Cadillac? Cadillac?? Is that one of them companys mounts a perfectly good V8 transverse and drivin' the front wheels so's you maybe need to pull the motor to replace some steering components and hafta wanna destroy yore hands to work under the hood? :-)

I wonder why?

Thanks. Shows how out-of-touch I am.

Must admit I didn't necessarily understand it all, but I suspect it's just semantics. Article said special equipment caused valves to stay "closed"? I thought a valve was closed when it was fully seated (which would imply that the new motors -are- fighting the compression-stroke-without-firing that I asked about). But that doesn't make any sense (to po' me, at least).

So ya can't even get a German-MoPar Hemi without the MDS stuff?

I asked the wrong question.

Here's a new set of questions:

Is anyone presently making substantial and reliable RWD auto(s) with 1 or more of the following characteristics:

1.) Absence of cylinder deactivation systems.

2.) Iron blocks.

3.) Iron heads.

????

Salut, Puddin'

"Mit der Dummheit kaempfen Goetter selbst vergebens!" (Against stupidity, the gods themselves struggle in vain.) -Friedrich Schiller (1759-1805)

Well, on the upstroke, there is compression with the valves closed, but you get that energy back on the downstroke - "de-compression" - I guess you would call it.

...or if the valves close on an intake stroke, there is energy used for "sub-compression" - or vacuum to create in the cylinder - but you get that back too on the upstroke.

Either way it's a wash.

Rob

I have seen exactly two of these early Cadillacs in operation. The first one was owned by an elderly gentleman who always drove the car in the typical elderly driver fashion for nearly 15 years. The computer would adapt to driving style and.... Every few months he would come back because the car was acting "sluggish". We'd clear the memory, Take it for a rip up the road at full throttle and (as he would say) it got it's pep back. ;-) cheap & easy "fix"

The idea was way ahead of the technology. Properly maintained even the early 4-6-8 Caddy's would operate as designed.. It shouldn't be too problematic now with better oils and electronics.

The other 4-6-8 Cadillac? It came in for a tune-up. Opened the hood and saw a rats nest of red wire where someone had "fixed" it..... Never even attempted to touch that one.

Don't worry about this being "cutting edge" technology. ABS started life in the 1950's, Airbags were in GM cars in the 1970's the 1930's Deusenbergs had Superchargers and multi valve engines. 1960's Corvair's had rear mounted air cooled turbo engines (yes, just like the 1980's Porsches). Fuel cells? 1800's (look up William Grove or something like that).

America has made a practice of being ahead of the world. This is what made America great and continues to make America great. It's just a shame we can't find a solution for the retiree's so Ford, & GM can start spending engineering dollars again.

If you're concerned about reliability buy a new one after they've been out a few years, that way you'll have a warranty and the problems the vehicles encounter will already be solved by the early adopters. .

experimenting....

No offence, but methinks "That Dawg Won't Hunt!!".

Imagine taking any 4-stroke motor (maybe a little Honda OHV mower motor) , disabling the valve actuation mechanism, leaving valves firmly seated by their springs, and turning it over by hand, say by spinning the flywheel. Reasonable to expect it requires zero net effort?

With an V8-4, you don't think it'd unbalance the motor's operation? I won't even ask re, say, a V6-3 (which sounds truly 100% crazy to po' me).

If the valves remain fully seated, it doesn't take a PhD in physics to perceive that unnatural acts are being committed to effective power generation/transmission? Even if 'twere practical to hold valves open, it'd be dragging around twice the weight of the pistons, con-rods, etc that produce power. Not consistent with overall design?

Cheers, Puddin'

No way it's zero net, but it's better than dragging pistons along doing work (which is what would happen with the valves open). The valves may float VERY briefly to a point where there will be nothing taken in on a downstroke - or 1 atmosphere in the cylinders somewhere around midpoint in the stroke.

Read my link above to see how Honda does it... it actually includes a microphone & the stereo speakers as part of the scheme!

See above.

That would be worse. See above.

Rob

Thank you, kind sir.

No comprendere, senor.

After noting that it was, indeed, a V6, I got as far as the microphone.

I did -not- fall on the floor laughing (take these things too seriously, I guess).

The phrase "Engineering Frankenstein" occurred to po' me ...

Strongly suspect that both Rube Goldberg and the Honorable Japanese that invented Godzilla would've been proud. :-)

It ain't that I'm against Technology. They've done all manner of very useful tech things over the decades. It's just that it gets truly out-of-control every once in a while ...

Cheers, Puddin'

Appreciate info re the old Caddy's ...

And there are -still- definite, if not generally understood, advantages -and- disadvantages of each innovation ...

Total labor on an average "American" car nowadays is maybe

60% non-domestic?

"We" may not have a solution, but they (Big 3+) likely will right soon, now. Involves application of proverbial ax by auto makers, partial subsidization of axed benefits by the "Fedral Gummint", using you-know-whose monies.

A very prudent approach, which I would follow if I were in a position to buy.

But it potentially goes beyond that with some design, etc issues.

Suppose I wanted to compare repair costs for, say,

1997 Lesabre's and Crown Vic's as they roll from 100k to 150k miles. Assuming that good accurate numbers don't exist, how would I formulate expectations of differential costs? All life's decisions are based on expectations ...

Same question for 2005 models.

Cheers, Puddin'

You asked... here ya go..... All Ford V8 gasoline engines in current production have aluminum heads.... rear wheel drive, and very, very substantial.... All Ford V8s in current production feature computer strategy that will disable the injector(s) on affected cylinders during a coil primary circuit failure event. So.... you can see the only thing left is iron blocks... Not one, but TWO of your requirements fullfilled. Further.... on those engines equipped with cylinder head temperature sense.... If the motor overheats, the ignition and fuel on a pattern of cylinders will be disabled in order to use ambient air to help cool the motor.

As I feared ...

Doesn't/didn't Lincoln, maybe others, mount a Ford V8 transverse for FWD?

Might be a good thing if it really worked properly (unlike the Idiot, Idiot Inertia Switch in my '94 Boid). Imagine passing an 18-wheeler in tight hiway traffic when it malfunctioned ...

Where? Where?? :-)

Ambient air? Thisun flew right by po' me. I s'pose they're throwing the warped-aluminum-heads issue a token fish ...

True or False: "Somebody (maybe even Ford) *could* design/build a traditional motor/drive-train (iron block/heads, etc) without idiot-proof features/circuitry of any kind, which would cost less and provide much improved reliability over what we currently see in the auto market."

Salut, Puddin'

The cam lobes are disabled (at least in the Honda VTEC), so the valves are closed. I assume some pressure leaks past the rings in the first few (hundred) strokes, and you wind up with a nominal charge that doesn't add or consume much energy during the piston cycle.

Have you ever started an engine that has a compression release?

I recall watching a huckster pitching an ignition booster module out in front of an old "White Front" store. Old Cadillac V-8, didn't run all that well, to be "improved" with the ignition module. Unplug one spark plug wire. See how rough it runs, just like an old engine missing on one cylinder. Here, let me add the ignition module, and, just to make it harder, I'm going to unplug another spark plug. Gee, look how smooth it runs now!

The pistons, rods, etc, are there for use when needed. More important in open verses closed is all the air that you would be pushing back and forth with open valves. Or the compression and intake load of running with valve train actuated, but fuel cut off, which I think every modern FI car does during deceleration.

I'm sure that Honda, GM, and Chrysler have some designers that thought about it before it was put into production. Maybe even a few with PhDs.

That's on the Accord V-6. The Civic doesn't bother. I can't tell when the valve train is actuated or not.

The microphone/speaker idea is very impressive in a Bose noise cancelling headset in a helicopter.

Odyssey, too...

Rob