idea, 4 cylinder to 2 cylinder engine conversion

[Frank Lee]

Cool- will want to know if/when you go through with it!

[sarguy01]

Originally Posted by Frank Lee

You mean Rest In Pieces.

Any EMers with a DoD vehicle have real-world DoD fe increase data?

A little late to reply to your post...

I bought a 2009 Dodge Ram Hemi 4x4 with 3.93 gears. It got at best, according to mileage/gallons math, 16.5 mpg on a highway trip. It had MDS, multiple displacement system.

I hooked up a light to one of the lifter solenoids to see when the system was on and off. It hardly ever came on. I shared the knowledge of the light and it seems the guys with the 4x4's and 3.55 gears, but the same model truck, were constantly in MDS mode on the highway. They were getting 21-22 mpg with a 390 hp Hemi. Compare that to pre-MDS, 345 hp Hemi trucks, 4x4's with 3.55's, getting 16-17 at best. But, to please this forum, I have no real data other then being the owner of 3 Hemi 4x4 Ram's and frequenting forums.

So in my personal experience, no, I never got an increase because the system never worked in my truck.

A thought. Thinking out loud through my keyboard... What if, a 2 cylinder turbo? The turbo would allow for those emergency situations where the car would need to move, but not be spooled under say, 3000 rpm?? Finding a suitable 2 cylinder that would produce low end torque to move a car effectively in an rpm range out of boost is an issue. Most 2 cylinder engines, like mentioned, are performance oriented designed to move 400-800 motorcycles.

Another thought. Use a tiny diesel from a generator. Check out Kubota's engine line up. They have 9-50 hp 2 to 4 cylinder diesel engines. They don't list torque though. I am sure a new one is going to be $$$ but there are plenty of used generators on Ebay.

[sarguy01]

Originally Posted by Accord_Guy

Hey, I'm new to the forum but thought I could add a little something here.
I've got a 94 Accord (2.2l) that I've been running successfully on 2 cylinders for the past month or so. I have not modded the engine yet to remove the extra drag from the 2 'spare' pistons moving up and down nor have I removed the rockers from the valve train. The effect thus far is that the engine runs a little rough at low RPM but runs sufficiently smooth and with enough power to achieve and maintain highway speeds. The ECU in this model is dumb enough to not care that I am only running 2 cylinders and does NOT post any codes. I have simply disconnected 2 injectors and connected a load on the injector lead so that electrically the computer thinks that the injectors are still there. I used old injectors and they are simply dangling down the side of the engine.
My plan is to complete the mechanical mods which include removing the rockers and pistons (leaving cut-off con-rods on the crank) and re-timing the balance shafts as best as can be to help with low RPM wobble. Once all this done I will be getting an emissions Test and doing a consumption test run of 400-500Km. I am fairly confident that this will work but would like to take it another step... these engines are usually fairly smooth at low RPM because they have 2 balance shafts, it'd be great to find the right timing to re-balance the engine to allow it to idle well as well. Your thoughts?

Please post your results when you get them.

[sarguy01]

Instead of killing two cylinders, why can't one destroke an engine and not have to mess around with the balance, valves, etc, etc??

Would the difference in gas mileage in between say, a 2.0L and a 1.5L be significant enough to pay for the cost of the crank and other machining required?

[Frank Lee]

For me anyway, the main idea is to do it with what's there and not spend lots of money. Integral with that is the reversability of it.

If within that engine family there exists a short stroke crank and other bits that more or less drop in the cost hit isn't necessarily that bad but still unlikely to pay back.

I think an engine swap to a purpose built twin or whatever has fewer compromises and greater chances for fe gain success but then one is looking at fabricating a bunch of custom stuff again.

[Accord_Guy]

G'day fellow ecomodders. I have lived the experience and want to say that...
Having run my 2.2l engine with 2 injectors disconnected thus running on only 2 cylinders has in fact worsened my gas mileage as it would seem that the O2 sensor is still trying to compensate for the whole double the air coming in through all 4 cylinders and only having fuel going through the 2 thing. So I decided to disable the valves for the 2 non-working cylinders by removing the rockers for the affected valves from the valve-train. I have simply removed the rockers from the valve-train and 'welded' the oil passages shut (all up approx. 45 min).
As you can see from the picture, the rockers for the #2 and 3 cylinders are no longer there.
Interesting results - The vehicle has gained significantly in performance and reportedly sounds like a Harley.

I've taken it out onto the freeway and it has no problems achieving and maintaining 100Kph... and is actually still loads of fun to drive.

Next MOD - I will remove the sump (oil pan) and remove the 2 pistons and con-rods, replacing them with hose clamps to block the oil passages). If I can remove the piston altogether from underneath I will, otherwise I will push them up and tek-screw them into place. The net effect will be that I will be running a clean 2 cylinder engine in closed-loop mode which should be able to pass the eTest and give me excellent gas mileage... Or, I will end up with a really big paper-weight and have to replace my engine. This engine had a bad #2 cylinder anyways so no loss either way.

I'll keep you posted.

Accord_Guy

[Frank Lee]

pistons gotsta come out the top

[saand]

Accord guy great post, thanks for that info gives me a lot more confidence in this mod. Especially good to see you have a 2.2L as well and your car can maintain 100kph without issue.
Before you make any more changes i would be very interested to know if you have any efficiency gains with only the changes you have made so far. In the event that removing the pistons ends up that your engine vibrates its way out of the engine bay what you have now might be a good half way point that others could do if you are getting an efficiency gain.
I think anyone looking to do this mod is looking for at least above a 5% gain so an inaccurate test result (not an ABA test) would still be very useful. So if you have any info on efficiency for a tank fill from your standard car compared to your now deactivated 2 cylinder engine id be interested to know.

Also how did you weld your oil passages shut. Is this done with a Tig, Mig or arch welder. I am not even sure what type of metal the oil passages are.
Anyone know if the oil passages could be closed up with some other method like epoxy or a plug that can be removed later if the mod doesn't work out.

[saand]

Hi All,
Today i have finally tried disabling a cylinder by removing the rocker on the exhaust valve of the cylinder and unplugging the fuel injector. I plugged up the oil passage by using a rocker from a wreckers which was cut in half so it is effectively a ring that just closes up the oil passage but doesn't activate the valve.
So after all this effort i tested it out. Some things i noticed are
Pros
- the car starts up without an issue (once i remembered to plug in the spark plugs).
- It can get up to speed without an issue

Cons
- The car lacks power and "chugs" up to speed which is not ideal.
- Higher revs are required before shifting up to a higher gear to avoid vibration
- it does sound a bit like a Harley, but its not too bad

From what i have seen it looks to me like this mod isn't worth it. For me the car is unpleasant to drive in with only 3 cylinders. I unfortunately couldn't measure the fuel usage because my fuel meter has broken recently however considering i had to increase the idle significantly and i need higher revs to change gears i would suspect the fuel efficiency improvement isn't great.

I am not sure how Accord guy has better performance when doing this same change, the only difference between our modifications is he has disabled the air inlet valves as well. I dont think the air inlet valves would make a difference but id be interested to know if someone disagrees with that.

So to sum up, i wouldn't recommend this (from what i have seen) for a 4 cylinder. For a 6 or 8 cylinder however this mod may be perfect.

[Frank Lee]

Mine wouldn't start on 2 and I'd be surprised if any 4 did.