I'm considering buying a cheap high milage toyota or saturn 4cly/manual tranny and trying to improve gas mileage.
My drive to work is 10 miles in the country. No stop and go.
If I was to remove two pistons and corrisponding injectors/lifters/rods, etc. Cap off oil ports on the crankshaft. I should get a 30-40% increase in mileage with, of course, a severe loss of power.
Depending on which two pistons you remove, it will run smooth. I have seen this happen by accident in another situation. (4 cly compressor missing two pistons from the factory.)
All I need is 50mph.
I will also strip all the unused seats and dash to lose weight. No A/C.
I have seen something like that done. Local mechanic's son was coming to see his dad from a town some 60-70 miles away He had his wife in an old Dodge, when it developed a severe internal knock.
The kid dropped the pan, identified the problem, removed the piston and connecting rod, and stuffed a rag up in the cylinder. He made it home with no problem, believe it or not.
Your idea would be a shadetree engineering job, but it wouldn't surprise me at all if you could get it to run more or less okay. You could use some bob weights in place of the piston and rod assembly.
Disabling the valves would pretty much isolate the empty cylinders, IF they seal reasonably well.
Not worth the effort imho. Even if you get the balance right, it will take a certain amount of power (burned gasoline) to propel that car forward. Whether you burn that gas in 2 or 4 cylinders isn't going to make that much difference over a 10 mile drive. Also to consider is that it will probably fail the emissions test.
Why not buy something like a used civic or corolla with a small motor and get 35 mpg.
Probably right about the economy. I dont doubt he could make the concept work, however.
FIL has a Sonoma with the small 4 cylinder engine, and it gets less than
20 mpg. Our 3800 V6 26 mpg or better than that...BUT, the V6 cruises at
70 mph at about 1800-2000 rpm.
The I4 spins up to as much as 3500 rpm to maintain 55 mph on a steep hill, and runs 2500 or better to do 70 on the flat and level.
Overall gear ratio, aerodynamics, engine management, and perhaps other factors apparently have to work well together to get good mileage and reasonable power.
Got a friend who removed 4 pistons from a 455 Olds for his mom to drive. It did run smoothly--a real 228 cubic inch v-4. It drove fine, other than obvious lack of power, but fuel mileage turned out to be much like it was with the full 8 cylinders operating. YMMV. s
waste of time... I doubt you would even get close to the mileage % improvement you state.
it you want a two cylinder the best thing to do is get a motorcycle
engines are designed as a complete unit.... not where you can just take off two cylinders and expect everything else to work fine and just make large gains in fuel mileage and decreases in power.
as far as I know they don't make modular engines where you just take off the parts you don't want. They do make some V-8s that apparently can save fuel by managing what cylinders it fires. I know Cadillac had this in the past and Dodge has it on its hemi engines. I don't think the Cadillac system was ever worth having.....
I'm not worried about an emissions test, my state does not have one. (we can also own GUNS w/o a license!!)
Buying something defeats the purpose, to save money on gas. If I bought a four thousand dollar vehicle to save .40cents/gallon, well do the math. Payoff would be way down the road. (about 500 trips before I started saving)
I'm already using a Honda 750 shadow that gets 50mpg, but come winter, its damn cold. It was not purchased for strickly saving gas, so the 3500 I paid for it is not the same. (its one of my hobbies for 30 years)
A chevy lumina I had with the V6 aluminum engine regularly got 23-25mpg to work, (30mpg on long trips.)
I don't believe there are any 2cly vehicles available in the states that I know of. I would love to get a SMART car and tinker with it. But, not available.
Of note, I was also thinking of putting a double flywheel (increase weight somehow) If these little 4 clys were long stroke, I know it would work. But the short stroke will really hurt the torque.
I respectfully disagree that the fuel milage would stay the same. If I inject 50% less fuel, and expect lower power output, and decrease speed, well below what it was designed for, I should use less fuel. (Plus less weight) I do understand your thinking though. X-work must have Y-fuel to perform.
I am considering using a motorcycle engine (water cooled) also. But the coupling to the transmission input shaft would require a pillar block bearing of some sort, and alignment would be critical.
I was just hoping someone else had tried something like this and I could learn something. I don't know how the computer would react to lower(?) discharge gas temps. What about the ignition pack? Would not allowing two plugs to fire cause a default failure code or kill the ign pack while trying to fire two non grounded plugs? Mass Airflow Sensor? Hmmm,...idle valve?
It takes a certain amount of fuel burned to create sufficient power to move at a given speed. Under your proposed design:
Four cylinders will use a certain amount of fuel per cylinder to move the car forward at 40mph. Two cylinders under a light load will have to burn more fuel per cylinder to create the same amount of power to move the car forward at
40mph.
Your solution will not reduce fuel consumption by the amount of fuel used in 2 cylinders. If you take 2 cylinders off line the remaining two will have to work harder by burning more gas. If your idea was correct we would all be riding around in cars with single cylinder motors.
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