convert v-6 to i-3

Well first off it won't even run on just one side. IF you somehow got it to run on three cylinders it wouldn't have enough power to move. Sounds like a REALLY bad idea.

Oh, it'll probably run. Don't know how a DIS will work, though. Recently had experience with a 302 ford motor that was an air compressor. Hadda a compressor head on the left bank & those 4 plug wires tied to ground & a one barrel on the top. Filled the resivoir tank in about 15 seconds. Ran real smooth too.

Cadillac proved cutting out cylinders to be a major failure. If you really want to improve your gas mileage, chop half the weight off the car.

This is deja vu all over again. When the early-mid 70s energy crisis came along, some people tried disabling cylinders in search of some marginal improvement in gas mileage. That's about what they got, too, considering that the rest of the car was still the size of a river barge and showed similar concern for aerodynamics and had what we today would consider primitive engine controls and a tragicomically lossy driveline.

Later, Cadillac came out with an automated V8-6-4 scheme that earned a reputation for balky driveability; I'd imagine that most were eventually hardwired into permanent V8itude.

Chrysler, GM, and, I think, Honda have some more-sophisticated schemes on the market or in the works now. If I'm not mistaken, at least some of these schemes shuffle the cylinders that are in powered use so as to even out the wear.

Note that Honda disables one side of a vee engine, as you propose to do, but uses some pretty sophisticated additional technology (apart from the sophistication of engine controls needed to give people the driveability they want) in order to get away with that radical approach.

See for instance

Cheers,

--Joe

V6 engines are designed to spread 6 power pulses (6 cylinders) over 2 revolutions (4 stroke engine) as smoothly as possible.

I suspect that with 1/2 the pistons out of service you will find the power pulses are very unevenly spread out. Hence you will find the engine to be very rough.

Super easy to check: disconnect the power to the 3 injectors or try shorting out the 3 spark plugs (think straightened out paper clips) and try driving it around.

You might also consider disabling 1 cylinder, then 2 cylinders, then 3 cylinders to explore the effects.

Good luck, I'd be interested to hear how it goes.

Try a V-4 or even a V2 instead, but check out the firing sequence for the best combination of impulses. My guess is that even if you get it to run, it will be rough indeed with probably a net loss in milage and will most likely fail even the most liberal emissions test. Why would you want to eliminate power for a van that is not noted for being overpowered anyway.

A much cheaper solution would be to buy a used car that gets approximately the milage you are looking for.

Chrysler is currently doing this with their HEMI engine.

------------ Alex

You might have something if you could disable a couple of cylinders on the fly.

Wiring to disable fuel injectors should be straight forward assuming the computer does not detect the failure and shut down.

I remember an article about some tests with going from 6 cyl to 4 for highway cruising.

If you are simply trying to improve cruising milage would it be a better option to change the gear ratios. ?

Or is that something we did with really old cars. You know the sort, carbs, distributors, room in the engine bay to see the engine.

Weight is the most important factor. Strap on a chevy small block to a VW bug kit car and you'll get 35 MPG. Strap on a bug engine to a 5000lb car and it'll be so overstressed that you'll be lucky if you get 7mpg.

That would only work if you had control over the valves. The load of compression would completely eliminate any possible savings and would in fact make for worse mileage than running on all available cylinders.

Caddilac's IMPLEMENTAION was a major failure. I haven't heard a single gripe about the Chrysler MDS (Multi-Displacement System) as implemented on the 5.7 Hemi in the 300C, Magnum, Charger, and Grand Cherokee (truck Hemis don't currently get MDS).

But either way, that's a different ball of wax than permanently disabling half the engine. With MDS, the whole engine is available for quick warm-up and immediate power whenever needed.