Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - idea, 4 cylinder to 2 cylinder engine conversion

saand · 12-03-2010, 10:15 PM

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.

12-03-2010, 10:15 PM	#79 (permalink)
saand Wiki Writer Join Date: Jul 2010 Location: Melbourne, Australia Posts: 236 bugler - '91 Mazda 626 90 day: 35.89 mpg (US) Thanks: 15 Thanked 25 Times in 22 Posts	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.