Ford Fiesta 1.0L triple to get cylinder deactivation

[Baltothewolf]

I don't really see it being an issue unless you go long periods of time without changing your oil, or if the car sits for years and years and the belt sits dry.

[DIMS]

Looks like they have 2 different options on the table...err engineering Lab.

1 : They mention deactivating any cylinder at any given time to make the most efficient choice. Complicated & more Expensive

2: Least expensive = Deactivate 1 & only 1 cylinder & given loads.= Not as good but much cheaper.

I bet they will go for #2

[cRiPpLe_rOoStEr]

Originally Posted by Baltothewolf

I don't really see it being an issue unless you go long periods of time without changing your oil, or if the car sits for years and years and the belt sits dry.

What makes me quite skeptical is about the life of a rubber belt being soaked on oil.

[MobilOne]

My experiences with Ford products is that the engineers will pick a belt that will last 2 or 3 hundred thousand miles; but by the time the car gets to production, a much cheaper belt will have found its way into production and it will dissolve in 30k miles.

[NoD~]

OK, after having driven my Insight enough... I couldn't imagine losing a cylinder at any time other than maybe idle. Killing idle seems to be far easier and safer, especially when you can auto-start it like the Insight with the hybrid system.

I actually looked at getting one of the 1.0L turbo Feista before the Insight. No regrets (mostly due to cost differences and MPG... only needed a 2 seater, anyways). Though, they look they like would be fun little cars.

[JohnAh]

I hope I have learned something after 30 years of general dedication to cars and engines, making my own turbo conversion once, some crazy engine modifications and having succeeded to reach and repeat 4 l/100km or nearly 60mpg (US) with my 40 year old Saab. :-)

Having a small underpowered engine MAY save a lot of fuel, but it's not a guaranteed success. High revs and badly matched fuel system, exhaust and gearing can totaly change the outcome. Adding a turbo to any engine can also go either way...

Regardless of HOW the engine takes care of the induction, it is a process that consumes some of the energy the engine makes. If a turbo is used that energy is taken from the exhaust pulses, that are "free" in theory, but in practise will cause some restrictions to the exhaust flow. Compared to a compressor/supercharger that runs on the crankshaft, the turbo is generally more energy efficient, but even an electric supercharger must get it's energy somewhere, and taking that extra path from the alternator and battery is probably even less efficient than running it directly fron the crankshaft.

Because of that, it may seems like some savings can be done by not running the compressor/supercharger/turbo at all, but if the engine is built to run with forced induction, it will most likely have a lower compression ratio than a naturally aspirated engine of the same maximum power. This means that running a supercharged engine without supercharger will probably result in poorer fuel economy!
-At least this is what I think is true after studying a lot of BSFC-maps and knowing about the importance of a high compression radio to fuel economy.

A turbo/supercharger is simply a good way to pack more power and torque in a smaller engine size. This also means less bearing piston area that causes friction. I guess however that a naturally aspirated engine can reach higher general efficiency by maximising compression ratio and optimizing valve timing. With a diesel it's different, since it always runs with "open throttle" and full actual compression. Here you can have a turbo for peak power and still have a much more efficient engine on light load.

Shutting down a cylinder will increase load on the cylinders still running, giving higher actual compression/combustion pressure and therefore better fuel economy. If the engine is in mid och high rev range the loss of some cycles will probably not give much more vibrations. Running an engine on light load at high revs is however poor driving generally, and I think it would be much better to increase fuel efficiency by proper driving school than having technology that at it's best can do some advanced guessing.

I gues there is an obvious reason that I can do much better with my simple old Saab than with a modern "electronic" car or even a hybrid. -I mostly know exactly what I'm doing in different situations, and most important, I know what I'm planning to do next. The electronics can only make more or less qualified guesses...

[JohnAh]

BTW, I think Toyota had some in-line fours at least some years ago, with cylinder deactivation during idle, or perhaps even at light load. I've heard such a car cycling slowly between normal mode (all four cylinders) and a more rough sound of fewer cylinders firing while talking to the owner utside the car. (she didn't know anything about the engine though)

In the 1940's and 50's there were some bizzarre petrol engine conversions called Hesselman diesels, mainly in trucks and busses. The most common engine was a 6-cyl Volvo engine with low compression (even for a petrol engine, I think it was around 7:1). The engine had powerful spark-plugs for ignition and two slightly special valves per cylinder, giving an extra good swirl. Once started on petrol the Hesselman could switch over and run on the much cheaper oily diesel, -probably with a lot of black smoke and poor efficiency. To keep cylinder temperature up, the idle was kept quite high, and to help it even more, half of the cylinders were completely shut off to make the remaining three work a lot harder. (probably resulting in an extra dense black turd while driving off again...) There were a lot of problems with these engines due to soot and inlet valves that could not rotate the usual way.

[oldtamiyaphile]

The energy to run an electric S/C does indeed have to come from somewhere. My proposal is to run it on an otherwise standard N/A engine for use as an 'overboost' function only when really needed.

Originally Posted by JohnAh

With a diesel it's different, since it always runs with "open throttle" and full actual compression. Here you can have a turbo for peak power and still have a much more efficient engine on light load.

Fiat's Twinair doesn't have a throttle.

[MetroMPG]

Originally Posted by JohnAh

BTW, I think Toyota had some in-line fours at least some years ago, with cylinder deactivation

VW demonstrated 4-to-2 cylinder deactivation and showed very good results at steady speed cruising. I don't know if it made it into production or not:

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

[cr45]

Originally Posted by MetroMPG

VW demonstrated 4-to-2 cylinder deactivation and showed very good results at steady speed cruising. I don't know if it made it into production or not:

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

It appears to be in production.

Active Cylinder Technology (ACT) : Petrol : Volkswagen UK