Creating a Switch to Shut Off Cylinders on the Fly

[SVOboy]

I saw someone talking about how on their old volvo they had made a switch to shut off two of their four cylinders while at cruising speed. From what I understand it is just installing a switch to shut of the fuel injectors going to each cylinder, but the spark and all that keep going...so, if I do this will it harm my engine or make it wear oddly? Does this seem like a safe thing to try out in terms of engine health and all that? Hmm, thanks.

[Matt Timion]

Do you have a link to the guy talking about it? I'd like to read more about this.

[SVOboy]

I got it in an email it was just like, I did that, and nothing about it. I will look for some though eh. And something about doing it with dpfi. ^_^

[diamondlarry]

I'm not sure if this is what he's talking about but here is a link to something similar.
http://autos.groups.yahoo.com/group/BetterMPG/message/2595

[SVOboy]

That's what I was talking about, haha.

[chasgood]

The new Chrysler 300 V8 does something like that. It automaticly shuts off 4 cyl's when the power is not needed. So it is a doable project.
If you worry about uneven wear set up all 4 injectors and every month switch from 1 and 3 to 2 and 4.

[SVOboy]

Yeah, a lot of the US autos are moving that way from what I understand, but really only the gas guzzlers, so, makes people feel good about themselves for gettin 10mpg instead of 8, sigh. I dunno why they won't do it for resonable stuff like I dunno, are there any US cars that get over 30 avg...? In any case, I have a 4 cylinder, but it only has two injectors, so you think I can still do this by shutting off one injector?

[chasgood]

It would be the front 2 or the back 2 cyl. It would depend on the firing order. It could make the engine run to ruff. It may just work better the more cyl there is. That is why car makers only use it in V8's. Wont know till you try it.

[Matt Timion]

This would be a VERY EASY modifcation to use. I'm curious though as to what happens with the two other cylinders? So the injectors don't shoot gas, but they still get air. The spark still shoots. I guess the momentum of the previous cylinder's explosion will still propel the piston downward, so i guess it won't lock up or anything. I dunno. For some reason I just get the feeling that it can't be good to do this to an engine. Will it cause emission problems?

Someone with a better understanding of engines has to be able to answer these questions.

The good thing about this is that it would be a VERY easy modifcation. It would be all in-cabin wiring. You could even hook up four switches, one for each cylinder.

Maybe a device could even be created that would switch between cylinders every minute. Minute 1 injectors 1,2,3 and on, and then minute two 2,3,4 are on... etc. etc.

Someone convince me this isn't bad the the engine.

[SVOboy]

Hopefully he can give us a straight answer about this, and with dpfi would be good for me too...^_^ Worthless dpfi that it is.