Making a V8 run on 4 cylinders???

Question

I have a 92 F-150 with the 302 V8. I was wondering if I could safely cut out 4 cylinders by removing spark plug wires and disconnecting injectors. I don't care the lack of accelaration this would cause, I do a lot of freeway driving anyways. I have been working on cars forever, and have gone to school for it as well. But I have never done anything like this or seen it. I don't see any problems that would arise from it. Because there are 8 cylinders and two are always working together, you just need to cut out half and make a 4 cylinder. Has anybody seen this. There are new cars which cut out 4 when not needed, but this way is a little different. Any input??

Answer 1

Doesn't sound like a DIY job. GM tried that in the 70's where they collapsed the valve lifters and the engine would run on either 4, 6, or all 8 as needed. The idea had some problems and never was accepted too well. They quit making them after a few years.
It might be simplier to just make sure your tires are well inflated and drive a little easier and slower. Good luck.

Answer 2

You can do it. It would be most effective to remove the push rods from the cylinders. For even running, they should be removed from every other cylinder in the firing order (like 5,2,3,8 or 1,4,6,7).
If you leave the valves opening and closing the cylinders will pump air out the exhaust, altering the air fuel mixture which is controlled by the Oxygen sensor.
It will also pump some of the fuel out too, even if the local injector is unplugged. This fuel will burn in the catalytic converter and cause an incredible hot spot under the floor.
If the valves are not opening, the spark in the cylinder will not make a difference, but removing the plug wires will increase the chance of misfiring.
My wife drove a 7 cylinder Chevy for two years, (due to a damaged cam).

Answer 3

Your could be in danger of twisting your crankshaft. Another danger is that the way your engine is tuned, means you will have a very lumpy feeling when you drive. The cylinder firing will not be synchronized. If you do do it, look on the side of the engine. It will have the firing order. I think it is: 1-3-7-2-6-5-4-8.
Your would need to knock out every second number: 1-+-7-+-6-+-4-+. This would be done to minimize the pause in between firing.

Answer 4

The 4-6-8 idea was done by GM and ruled bad after lots of warranty work to fix that bad system...

Most of the newer engines are built stronger and use the computer to knock out the cylinder and can do it randomly so it doesn't damage the engine.. doing it yourself you run the risk of ruining the engine as someone said due to the loading you are putting on the motor by running it on 4 cylinders in My opinion (especially since the motor wasn't designed for the abuse)

Answer 5

You cant do that.

Instead block your accellerator really far until it puts out what seems like 25-50 hp, like a really small 4 cylinder car. You are blocking out that extra HP your engine is able to produce, but you dont need all of that. Chevy used to advertise that the Cavalier only needed 11hp to cruise at 55mph. also there is some guy that put a 10hp Diesel engine into a Geo to prove that you dont need all that horsepower.

I blocked my accelerator on my 4cyl "K" car and now get 30mpg in town as opposed to the 22 I was getting.

Answer 6

I'm guessing it would work - but even if it will, that vehicle will be dangerously slow - mopeds will smoke you at stoplights - kids on bicycles would give you a run for your money.

Seriously - even though the 4 cylinders would be ok on the highway, it could be downright dangerous at times. Better to sell this F150 and buy one with a six or a Ranger than to do what you're suggesting.

Answer 7

Too much parasitic drag from the 4 non-working cylinders.

Not worth the trouble, IMHO. The extra weight you're lugging around would make any gains in mileage a non-issue.

Answer 8

Bad idea. It will throw the motor off balance unless you nail the timing, and it still might not work right, killing the bearings. Whats done now is not as simple as what you are trying to do...

Answer 9

I'd say bad idea. You would have to find out the firing order and somehow figure out how to stop those cylinders from sparking. I wouldn't do it, I'd sell the truck and buy a beater.