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-   -   Cruise control cylinder cut. (http://www.fuelly.com/forums/f9/cruise-control-cylinder-cut-7243.html)

severedgein 01-09-2008 05:22 AM

Cruise control cylinder cut.
 
sorry for the alliteration...

my ideal idea is a 2 cylinder shut-off when cruise control is activated, coupled with a hydrogen generator to make up for lost power. any ideas? i understand that the hydrogen generators are not efficient, and i'm really not worried about the battery draining. the hydrogen would simply complement the combustion, and help prevent detonation from an extremely lean situation.

for this i understand i need proper tuning. i can handle that.

my questions basically lie with the wiring and set-up as a whole. i want it to be one fluid step. i.e.: setting my cruise control automatically cuts fuel to two cylinders, turns on the hydrogen generator, and corrects the voltage(s) sent to the ecu. i suppose this could even be done with water injection, but if hydrogen supplies extra power, i think that's the better route.

with this set-up, i believe i (and anyone else) can acheive 60+% highway mpg (or l/100km) improvements, even taking into account the extra load put on the engine. if modern cars only need in the realm of 50hp (or even less) to maintain highway speed, why are we even using all this extra power??

comments/ideas/opinions please.

GasSavers_Ryland 01-09-2008 06:42 AM

do a search for cutting cylenders, others on here have tried it, explaned very well as to what they did, and why it didn't work.
a number of vehicles that are for sale do cut cylenders, but they do so with very carful enginering, mostly useing a very complex head and rocker arm arangement.

itjstagame 01-09-2008 08:44 AM

If you have a fuel injector on each cylinder you could just have a relay that cuts the grounds to two of the cylinders when you hit the cruise button.

I wouldn't bother with the hydrogen, I've always shown worse results with it and the fuel cutting should be an independant experiment from hyrdrogen anyway.

I'm also not sure what you mean by correcting voltages, you shouldn't need to do anything else, fuel calculation will remain the same and be fine because you still want to inject the same amount of fuel for the same amount of sucked air in the intake per cylinder (you're going to be pumping air through the 'dead' cylinders). The only issue I can see is possibly with the O2 sensor reading wrong since half the volume of air will now be unburnt atmosphere.

The car companies that do this now (Dodge and Chevy I think?) go one step further and have sophisticated ways to collapse the lifter on those cylinders and prevent them from sucking in air and expelling unburnt air to the 'dead' cylinders. This still isn't ideal though because the clyinder is still sucking against a closed chamber and building vacuum (which is robbing efficiency). There was another thread where a guy turned his car off at the top of a hill and saw how far it'd coast in neutral and then did the same experiment again but left the car in gear (so the car was forced to spin the engine) and it went much less of a distance, engines are a major drag when not combusting.

One thought a friend of mine had was maybe have a seperate valve/chamber on each cylinder that opens when the cylinders are 'dead' and would equalize pressure to them. That is say you build a valve into the spark plug or something and hook it to the other cylinder you plan to kill, they would have 0 pumping losses because when the one pulled down the other would be pushing up, they'd just be pushing the same air back and forth. I couldn't really picture what he meant when he said building a valve into a spark plug, the way I'd do it is drill a new valve into the head away from the camshafts (so out the side on DOHC car) and actuate it with an electromagnet. Electromagnets can't pulse fast enough to be fully electronic valves, but you're going to turn this one and off for minutes at a time and this will work perfect for this.

Either way, make sure to cut matched cylinders (that is 1 and 3 or 2 and 4), because other wise I would it would be too lopey and put too much stress on the crank.

kamesama980 01-09-2008 09:14 AM

Quote:

Originally Posted by Ryland (Post 88029)
do a search for cutting cylenders, others on here have tried it, explaned very well as to what they did, and why it didn't work.
a number of vehicles that are for sale do cut cylenders, but they do so with very carful enginering, mostly useing a very complex head and rocker arm arangement.

And have proven incredibly reliable and effective...well they haven't blown up but they're not as economical as an import engine of similar displacement. less power and less mileage...still. go GM and chrysler.:thumbdown:

cfg83 01-09-2008 02:47 PM

severedgein -

Everything I've read on this website points to 4-bangers being bad candidates for cylinder deactivation *unless* they are horizontally opposed boxer engines, as in Subarus, VW Beetles, and Porsches. What engine are you planning on using?

If I were you, I would spend time reading the newsletters that are here :

Hydrogen Boost Newsletters - Research and Development Reports
http://www.hydrogen-boost.com/newsletter.html

In this newsletter example below, the developer admits that the hydrogen booster has "negative FE" zones, which is one reason why I think he is an honest broker :

Diesel Dynamometer Testing Analysis - September 2007
http://www.hydrogen-boost.com/September%202007.html
Quote:

... Our Model 20 is designed to produce enough hydrogen for even the largest gasoline engines including those of 8 liters displacement. So those who are installing and operating on a one liter Geo Metro engine may be only preventing improved mileage when producing hydrogen at 20 amps.

Recent changes in installation instructions provide for installation of a throttle position switch or intake manifold vacuum switch that would only turn the hydrogen generator on during acceleration and high cruise throttle settings. This will avoid most of the negative savings operations. Adjusting the vacuum switch to optimum setting should practically eliminate the negative savings zones. ...

I'm NOT suggesting that you buy this one because it costs a lot of $$, but there is a lot of practical information in the newsletters.

CarloSW2

severedgein 01-10-2008 06:42 AM

i have a H22a1 engine. i could also engage VTEC to allow better air flow to the cylinders.

but yes, my main concern is the o2 sensor reading extremely lean. i'll work out the kinks as i go, but i'd like to at least try this.

dkjones96 01-10-2008 01:33 PM

Have those of you with VTEC ever considered a radical cam grind over disabling cylinders?

You could setup the cam switch so when it activated it left the intake valves open for about 50-66% of the compression stroke. That would make it where you can floor the engine to reduce pumping losses working against a vacuum on the freeway or just under floored and get an FE increase. It's similar to miller cycle except way more radical and geared towards fuel economy since you don't have the supercharger..

Just an idea. You'd have to go standalone to get that to work right and if you want a perfect setup you need to try different durations until you get your engine putting out just enough power to attain the speed you want to always cruise at.

severedgein 01-11-2008 04:07 AM

so basically, i'd have my throttle wide open on the highway and 60-65 would just be my top speed due to the powerband?

GasSavers_Erik 01-11-2008 04:33 AM

Quote:

Originally Posted by severedgein (Post 88234)
so basically, i'd have my throttle wide open on the highway and 60-65 would just be my top speed due to the powerband?

Yep- I hope you live in Kansas because if/when you come to a hill, your top speed might go down to 45 :D

Unless you go back to using all cylinders or downshift and rev it more.

dkjones96 01-11-2008 07:25 AM

Quote:

Originally Posted by severedgein (Post 88234)
so basically, i'd have my throttle wide open on the highway and 60-65 would just be my top speed due to the powerband?

Exactly, and when you need more power you switch te VTEC back over to the original cam setting and it drives like normal again.


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