Conversion idea, 2L inline 4 -> piston boosted 1.0L 2 banger? Warning....Long thread

[nubie]

Now that I am thinking of cylinder de-activation, why not get ahold of a Vtec-L or VVTi-L (honda or Toyota) and then just grind off the low-speed cam lobe on the cylinders you want de-activated, grind the high-speed cam lobes down to a economy-friendly profile at the same time, then run the engine with the Vtec circuit continually active for all cylinders, off for 2-3 cylinders.

Would it be possible to do this by adjusting the rockers very loose? I don't know.

Strange thought, why not run the spare two cylinders as an air-compressor and have a hybrid air-powered system for acceleration?

I would pull the pistons, rods, have the crank re-balanced, plug the oil passages to the missing rods, grind off the cam lobes, and run a small turbo.

As I have mentioned before, the smart money may be on sourcing a 1.2L or 1.4L motor/block/crank from the euro/world market (South America maybe?)

[nubie]

Originally Posted by Heihetech

Hi all. This is my first post here, but I already posted my invention called
Dynamic Cylinder Deactivation, or DCD for short, in a thread with the same
name. DCD makes engine displacement variable by electronics. So just by
clicking the button, the number of active cylinders in DCD controlled engine
can be changed in no time, saving fuel with reduced power. But when you
need larger or full power, just clicking the botton to go back to it was no DCD
control.

DCD concept has been made into DCD Controller product these days. So
anyone who plans to do 4cyl to 2cyl mode, or 6cyl to 3cyl mode, is welcome
to try this electronics gudget before you start mechanical moding. DCD
will let your dream become true, with reasonable time and expense, saving
fuel while keeping good drivability.

I have a Popular Science here from 1984 and GM has cylinder deactivation. It is simple in theory, but the least expensive and most reliable method is to use parts from production cars with cylinder de-activation. I know of Honda and GM/Chevy systems using cylinder deactivation.

[Heihetech]

Originally Posted by nubie

I have a Popular Science here from 1984 and GM has cylinder deactivation. It is simple in theory, but the least expensive and most reliable method is to use parts from production cars with cylinder de-activation. I know of Honda and GM/Chevy systems using cylinder deactivation.

Tranditional cylinder deactivation is a mechanics based solution that causes
a lot of headaches to do aftermarket retrofitting. But DCD is an electronics
based solution that competible to most of existing vehicles for aftermarket
retrofitting. Easy to turn on and to turn off, no mechanical mode involved.

[nubie]

I think we are off-topic here, your idea of DCD is intriguing.

I wish you would come straight out and talk in plain engineering terms "DCD" is marketing speak. Here at Ecomodder you could just say "pattern based fuel injector cut-out"

I would like to see the vibrations set up by such a system, if they aren't too much it would be interesting to try it.

I am assuming that implementing such a system with an open fuel injection system such as Megasquirt would be relatively cheap. Say $250 or less if the user handles the programming and soldering of the computer.

I would of course like to see how this conforms to smog legality, it can't be easy to keep the oxygen sensor or the catalytic converter happy when regularly skipping injection events. So the fuel mixture in the active cylinders may not be ideal. I would expect an oxygen sensor for each cylinder may be necessary to keep closed-loop operation, as well as intelligent handling of the extreme lean condition that will happen as the fuel injection is cut.

I believe there is a reason the OEMs don't do this, perhaps it is because they have the money for a mechanical system and a mechanical system is superior, or because the vibration and harshness is unpleasing and specialized engine mounts need to be designed.

[Heihetech]

Because both the Conversion idea and DCD are related to cylinder
deactivation, so I'd like you guys know something about DCD.

I think "pattern based fuel injector cut-out" isn't enough for DCD, as you
have mentioned, some "intelligent handling of the extreme lean condition"
must be applied at the same time. The solution is wideband oxygen sensor,
by which the fuel loop can be closed at higher points of lambda, much
higher than regular lambda = 1.00, according to the requirement of DCD.

Expecting an oxygen sensor for each cylinder may be nice, but too expensive,
so DCD will use only one to detect overall exhaust mixtures with oxygen,
yielding high lambda readings. However, inside each of individual cylinders,
the burning will be kept in lambda = 1.00. In case of V8 or V6 engine, two
wideband oxygen sensors must be used, one for each bank. These 2 sensors
alone would cost you $250. Yet DCD controller will still worth the money,
based on its 8% to 18% fuel savings. It can be paid bcak within one year
for professional vehicles like taxi an livery.

OEM's? They don't own DCD patent, they have to be licensed to try. I think
once DCD has been verified and proven by massive aftermarket retrofitting,
OEM's would come to enjoy DCD. Hope OEM's will find out DCD through this
post here.

[nubie]

Interesting for sure, I know of one fellow who is cutting cylinders on purpose to make the engine sound like it is an old engine:

Finnishing Touch: Cosworth-powered Ford Model A — Autoblog

He has a new engine in an old Model A and he cuts out the cylinders to make it sound like an original Model A engine is still inside.


I don't understand how you plan to handle the fuel loop with an oxygen sensor, I assume you would need to provide a "virtual 02 sensor" signal to the original computer and attempt to keep the cylinders at the correct ratio.

It just seems as though the OEM's have tried this already, unless the patents were granted in the 1960's.

Don't forget that the OEM's have direct injection where they atomize fuel in the center of the combustion chamber and ignite it very lean with a layer of air insulating the combustion chamber from the lean burn.

I am afraid you are sounding like a snake-oil salesman, either you have solutions or you have thought of solutions. If it is as simple as you say, either provide a product or share your knowledge with the modders here so we can build our own. I think this thread has been de-railed enough, it is about using extra pistons to boost the volumetric efficiency of pistons still using a normal combustion cycle.

I am of the opinion that putting a production engine with cylinder deactivation or a smaller engine with a conventional supercharging device (such as a Turbo, roots or centrifugal) is a better way to spend your personal time and money at this time. This time being before you have an actual product for purchase and are just yanking everyone's chain.

/done feeding the troll

[Heihetech]

In DCD Control, fuel loop is closed by using a wideband oxygen sensor to
detect high-lambda area. So, if the engine has had lean-brun in it as you
mentioned, the fuel loop will be closed at even higher point.

There might be many good ideas or inventions in 1960s. Yet by that time
there was no computer, no ECU, NO CLOSED FUEL LOOP, no oxygen sensor,
any good idea was just a dream, hard to BE implemented. Nowadays we have
had everything include DCD, so that DCD product can be implemented, and
NICE DREAM OF DCD HAS BECOME TRUE!!!

The message I want to release here is that DCD is a pure elecronics solution,
except replacing oxygen sensor, there will be no mechanical work involved.
It is worth to try, easy to handle, and the result is your fuel savings, from
5% to 13% according to driving conditions (based on my tests on 4-cylinder
vehicle, 8-cylinder vehicle could save even more).