gxlbiscuit

i have a good bad idea... do you think its possible to run just one rotor for better gas mileage on the highway ??? killing fuel and ignition just letting the oil injectors lube the housing. im debating if doing so would make the single rotor work harder though. i like taking my car to different places around the country but since the first day i have owned the car i have never gotten mileage better than 220 a tank not including slightly below a quarter(what i call "reserves") about260 runing on reserves....(not wise) so yeah anyone think itll work?

lovintha7

I think it'll put too much stress on one side of the e-shaft. You might snap it in half. The one rotor has to pull the car, and drag the other rotor too.

TII: Judgement Day

I wouldn't do it.

I have heard of people doing it and nothing negative happening, but I wouldn't take my chances. Just doesn't seem to be smart.

fcdrifter13

piston engines have been doing this for a long while and also desiels have started. A diesel engine has to cut the fuel and the air to a cylinder at the same time for it to work. Otherwise the non running cylinder would just become an air brake slowing the engine down. With computers being put in cars now a gas powered car that does this has electronically controled vales so when the car is on the high way just crusing it closes the intake vales so air does not enter the combustion camber. Thus not causing stress on any part of the engine. Fo a rotry I am not sure how you would do this. maybe have a plate that closes off the intake runner to a rotor.

t-von

iTrader: (8)

http://www.rx8club.com/showthread.ph...highlight=idea

J-Rat

iTrader: (2)

Ummm.... wouldnt do this if you premix..!

Makenzie71

Wouldn't work...your active rotor would be over stressed and fail for similar reasons as listed in fcdrifter's post.

RandomHero

iTrader: (2)

Cadillacs have a function that shuts down a couple cylinders in an overheating limp mode situation, in effect, turning the "dead" cylinders into air pumps. Sometimes when people blow apex seals on one rotor, they will continue to drive or run the engine with only one rotor functioning. The natural thing to think, is that this would put stress on the other working parts, but thats going beyond my knoweledge.

fcdrifter13

I didnt say that it will fail this is a proven use on modern cars. I just do not know what the effects would be o a rotry motor. It would be stressed but not as much as you make it seem. It would add to more stress but not in the way you are putting it. On the piston motors that have this system and run everyday the added stress is due to over working the cylinders that that are running versus the ones that do not. The average rebuild time with a piston car with this system the time periods were dercreased from 200000 in the most extreme cases with proper maintance was decresed to 150000. This is a major increase in the rebuild intervals but the cost savings of the gas in the long run out almost negates the cost of a rebuild.

But this is on a piston motor. A rotory motor is a wole different can of worms. because you have only 2 rotors it would almost impossible to have a smooth running engine on one rotor. THe only reason a car with pistons has a better smoothness is because a 4 cylinder motor has 2 pistons that come at the same time and 2 that are down at the same time. All the cars now that have electronicly controled valves simple change the timing to where the motor is basically a 2 cylinder. I can explain in more detail if i could use good pics. But then you come to a rotory motor that is basically a 2cylinder in the first place. if you turn off on of those "cylinders" the motor would start to run unsmooth and would have a hard time crusing at low revs.

This all makes sense to me. But I am a mechanic (about to recieve my ASE certification if they lower the age limit) so I have a basic understanding of motors and how all the systems work.

Makenzie71

I did.

uRizen

iTrader: (2)

Too bad there isn't a front rotor disengagement system so when you're cruising and don't need the power the front half of the e-shaft disengages and the front rotor's fuel and ignition cuts off until you need the power again. I don't think it would work too well though since I've heard alot of people having problems maintaining freeway speed on a blown motor.

Makenzie71

Ever seen how well engine brakes work on semi-tractors? Same effect, just done from a different angle.

TII-aholic

wouldnt this cause the balance to be off and create a very bad shaking violent motion from side to side due to the balance being off?

Makenzie71

No. Why would it?

fcdrifter13

thats what i said in my post. Nowadays all trucks have engine brakes but back in the begining it was just the jakebrake. Closes the exhaust valves when they are supposed to be open. thus causing copresion and slowing the vehicle. Thats the big GRR GRRR GRRR should you here when the semi is slowing down. Man i hope I wrote that down right.If not Im sure Ill be corrected.

TII-aholic

well i know when i blew my motor and was only running on one rotor it shook very bad. so idk its just what happened to me

Makenzie71

That shaking is caused by an unsteady running enviroment, not an imbalance. Go drive a 3-cylinder Geo and bog the motor and see if it sounds/feels familiar...

ilike2eatricers

I would say 220 or 260 a tank is not bad at all for a t2. If you plan to run on one rotor you should plan to be flooring it the entire time on the freeway. That one rotor will kinda have to "carry" the weight of the other inactive one, it might freewheel a little but it'll definately put more load on the active one. Ask me how I know this (failed front primary injector).

86rx7fromohio

if 260 isn't bad than i shouldn't bitch about 300 or so miles on a tank.

gxlbiscuit

my car is not 260 you drive it too the 260 mark and you are out of gas at 261.... i did it in the desert.. made it to 260.5 i need to calibrate my gas gauge

savana

what your referring to is modular displacement,the problem being if you were to shut down a rotor at freeway speed rotational inertia and balance would be affected so greatly that more throttle opening would be required to sustain that momentum and by opening the throttle more you are no longer saving fuel in my opinion the best idea would be to just shut down the rotor at idle only and send a larger pulse width signal to the idle control valve to allow leaning the mixture enough to raise idle and sustain combustion basically the same as mivec md

savana

it would create a huge imbalance as the power strokes would be further apart and unbalanced. The same reason many 4 cylinders run balance shafts to counter the rotaional unbalance caused by widely spaced power strokes

Makenzie71

What? No it wouldn't. It's also nothing like an I4. Eliminate one rotor and you've not created any kind of imbalance due to uneven power strokes because you're STILL going to have 3 combustions on every rotation of the E-Shaft and they're going to continue to be 120* apart (as opposed to 60* apart with both rotors working).

Piston engines (not just I4's) have balance shafts because it's impossible to have a crank shaft that is symetrical.

fcdrifter13

ok go unplug both of the plug wires on one rotor on your motor and see what it does. And unless i am special my car goes nuts and looks like it wants to jump out of me

Makenzie71

It isn't doing that out of a sudden loss of harmonic balance. It's caused because, instead of aiding in creating power, the dead rotor is acting as a brake on the engine. The engine runs roughly and vibrates because it's in a constant, and losing, struggle to continue to run.