BigWillieStyles

Well guys im not sure how common Natural gas is in the states, but in Australia it is quite popular. We growing gasoline prices nearing the $2 mark, i was wonder if converting to natural gas is manageable? Ive seen old SA22s advertised recently that utilize natural gas.

Natural gas has almost 0 emissons and a higher octane level than normal gasoline. Its is also alot cheaper than normal gasoline. Australia has alot of natural gas reserves that havent even been touched as the demand is somewhat low.

It would be great to have the a dual fuel use. Using natural gas when commuting and petrol when you want a bit more performance. But im sure with the right tuning natural gas could have great potential.

Im wondering if anyone knows of any FDs that are natural gas powered?

Herblenny

iTrader: (13)

Far as I know.. NONE.. Also, do you mean Propane or literally natural gas??

I do remember back in the days when people used propane to cool the intake charge.. Buddy of mine back when used propane injection on his FD.. But running 100% on Propane, I'm not sure.. My guess is that its not going to work as I think energy that gives out from propane isn't high as 93 OCT gas.. hence you might have to use far more to produce same power.. Again, I'm not an expert in this field but I think it would be a BIG waste of time unless the gas goes up to $10/gallon.. but then I would switch to E85 or get an electric car instead of trying to make the rotary a fuel efficient car.

Kento

He's most likely referring to LNG (liquified natural gas), which is used frequently in public transportation and municipal vehicles that have easy access to LNG delivery systems. While LPG (which is usually primarily propane) vehicles are everywhere in bulk transport (forklifts, etc.), propane actually has far less energy content than LNG.

The fuel systems for gasoline and LNG are obviously completely different, which would complicate matters greatly. LNG systems typically operate at a minimum of 100 psi, and you would need an additional fuel storage tank for the LNG. I think there are vehicles that can run on both, but the complexity of the fuel delivery systems surely adds a ton of weight as well as a maze of additional hoses and check valves, and I'm sure you wouldn't be able to switch them on the fly with something as susceptible to detonation as the 13B-REW.

Herblenny

iTrader: (13)

quick google search...



Again, looks like its better to run E85 instead.. especially if you want to go back and forth with Gasoline and something else..

Herblenny

iTrader: (13)

If its LNG

alexdimen

iTrader: (13)

I agree that it's probably a waste of time, but $2/liter is almost $8/gallon

BigWillieStyles

I didnt realise that i wasnt used in the US, natural gas or LPG is a popular fuel in Australia. Reserves of LPG are far larger than that of oil.

Apart from LPG being alot cheaper than gasoline/petrol, it is also healthier for the engine, has a much higher octane rating, emitts almost 0 emissions and is in no way toxic. It is actually worse than CO2 for the environment if it is released directly into the atmosphere. but when burnt creates almost 0 emissions. Imagine having a 500hp car, no cats and still passing pollution tests.

Ive actually done some research today on this and ive found lots of rx7s using LPG as a fuel source. I will post up some more info later (im at work now).

Heres a quick summary of LPG

BigWillieStyles

In Australia LPG has been used as a source of fuel for many years, and many cars in the past- came with a pre-existing LPG setup. 3 out of 4 of Australia big car makers are working on releasing LPG powered vehicles. Australian government also hands a car owner $2000 towards getting a car a conversion.

Ive found many cars, including Rx7s running LPG with excellent results.

For Australians, this fuel is almost 1/4 of the price that gasoline/petrol is now.

Well using LPG is definitely not more fuel efficient, its actually 30percent less. But it is very cheap and would allow me to drive a car that is actually good for the environment, not bad. Which is actually quite important to me.

Check out this BMW M3 doing 318km/h with 522hp on LPG. Plus is you search youtube you can find rx7s.

http://www.youtube.com/watch?v=UswGlKQyAr8

Herblenny

iTrader: (13)

If you feel that strongly about it, you should definitely do it..

But you should consider this.. Again, I would like to emphasize that I'm not an expert.. So, do your own research and don't take my word literally.. just something to think about...

Since BTU is lower, you would need 50% more volume to get similar power.. Which means you need bigger or more injectors, modified fuel delivery system, better sparks to burn this higher volume of fuel (ignition)... I'm not sure if it will burn cooler but I guess you could make up some power via timing.. who knows.. But I'm guessing its going to take quite a bit of mods and R&D to get it running. Again, Everythings possible.. even V8s in an FD

But if I was really concerned about the environment I would build an electric car.. Wait, someone did do that to the FD (which most of us thought they were CRAZY!!).

NissanConvert

iTrader: (1)

What about hydrogen? Where does that stack up on the btu list? I've seen something about using natural gas IIRC- on a first gen. Again, if i recall correctly it had to be carbeurated (sp). Mazda has already done research on a hydrogen rotary using the rx-8 platform. It made less power but was successful.

Mazda hydrogen rotary?

Herblenny

iTrader: (13)

BigWillie,

Now I'm confused.. Before you were talking about Natural Gas and Now LPG?? You do know there is a difference right?? What you have define in the quote is LNG not LPG.. Also that BMW is LPG and not LNG...

gio64

iTrader: (1)

I know from direct experience that LPG is widely used in Italy as well. They have places where you can refuel that are easily found on the territory; gas prices are naturally the "stimulant" for this type of conversions.
While I don't have scientific data to post, I know from direct experience (friends who have this system) that it is an improvement over methane systems, it can be switched on the fly, but it does require an extra fuel tank, extra lines and some adjustments to the electronics setup. To conclude, it won't make more power than gas, as the common wisdom on this matter says that you'll lose some power, not an extremely high amount, but some nonetheless. One detail I can recall which might not be good for rotaries, is that running cars on gas (methane or natural) "dries" the engine up and it is always suggested to reintroduce gas every so often, just to keep things moist... Not so sure it would be good for a rotary.

Personally, if you have a sports car and can't afford the gas... well, you shouldn't have a sports car. But that's just me.

My practical .02 $.

Herblenny

iTrader: (13)

Thats funny you said that.. Because this is what I said to someone yesterday about owning an FD.. LOL!

BigWillieStyles

Im talking about LPG which is extracted from natural gas in Australia.

Well i can most certainly pay for fuel costs, infact ive been considering buying another FD recently. But i am thinking more about the future and from an environmental perspective. It would be nice to drive a low emission rx7. And i would like to somewhere down the track get an old FC for commuting and had often pondered at the idea of LPG as it is very common in Australia.

BigWillieStyles

for people interested, ive found that Australians have been looking at this for a while and some people have got it installed, check the link.

http://www.ausrotary.com/viewtopic.p...&highlight=lpg

Herblenny

iTrader: (13)

LPG = Liquefied petroleum gas - Which is mainly Propane
LNG = Liquefied natural gas - Which is mainly Methane

And quote from Wikipedia

I don't know where you are getting your source but LPG and LNG are not the same..

Herblenny

iTrader: (13)

regarding to this statement.. I have to agree with glo64..

As he said, you don't know what its going to do to the internals of the rotary engine and reliability of the engine.. As you already know, Rotary engine requires oil injection to lubricate the apex seals. Without it, the engine lifespan reduces quite a bit.. So, if you were to convert for the sake of saving the environment, then you certainly don't want to "burn" dirty oil??. Yes, its small amount but still beats the purpose as you speak.

Again, If your heart desires to do this conversion, DO IT! But I think it would be wiser for you to just let it go and go buy a hybrid instead... I gave up thinking about saving the environment when I bought my FD and surely, I would never convert if its available as a kit.... Unless Gasoline will no longer available to me and only option will be Propane(LPG) or Ethanol (which I would do before LPG)... Then I might switch.. but I highly doubt that will be anytime near.. and if so, WOW! I don't think I'll be worrying about MY FDs I'm sure something major will happen prior to that... LIKE WWIII!!!

BigWillieStyles

your probably right, i was just interested if anyone else was running LPG. I just cant see myself driving anything else!

bumpstart

http://www.youtube.com/v/FP27scNOKtQ&hl=en

closed loop carb set up good for 17 -20 L LPG per 100Km driving hard
( about half the cost per 100 km of a mild boosted turbo rotor on 98 octane petrol )

its pretty much an out of box closed loop impco 225 kit for a 4.0 to 5.0 ford
or 3.8 to 5.0 holden commodore ( chev ) up to 2006
( emission laws suit Australia )

the only power i am losing is down low from my 4 way idle single throttle TB set up
( and mild port )
just like an over-large weber, i have to feed throttle under 3000 rpm
and i have some small losses in idle quality ( still 16 inch Hg vac at 1000 rpm )
after that it will match any petrol rx7 with aftermarket EFI for speed it can rev and smoothness up to 9000 rpm

i drive everyday with 3.9 gears and 10 psi and that will mix it with 6.0 307 Kw commodores
( aussie chevs )
this motor has inadvertently run 18 psi a few times and lived
providently due to plenty of reserve in my ignition timing
( its a modded curve 12aT dizzy as direct fire , not programmable ignition timing )

i am running a curve that spans 8 to 22 BTDC mech timing with the trailing pickup used for its vac pot ( greater vac advance stroke )
( i have no trailing ignition whatso ever )

for idle, i have a switched ABSv ( air bypass solenoid valve )
used to lean things down at idle for the rotor
( the convertor will be a little bemused at the rotary vacuums and tend to err rich at idle )

the switch is open ( ABSv shut ) to help cold cranking draw mixture to motor
( about 6 - 8 secs when cold in morning )
- i am lacking the cold shot solenoid on the convertor that other cars will used to cheat the cold start

ATM the switch is manually controlled
( i can close the bypass for cold start and for hot operation as when the gas vapour pressure is high/ density low = leaner when hot )

but soon i will have it hooked up with some dead band switching from revs around 2000 rpm
and also perhaps from the radiator or water pump housing thermo switch
to auto flip over at high water temps


all very basic stuff, all simpler and more effective than most imagine

dhays

iTrader: (1)

Very nice. Years ago my family had a motorhome that could be switched from gas to propane and back. The Propane gave less power but was a lot cleaner. I'm not sure I buy the "all very basic stuff" statement. It may be basic to you, buy you live upside down anyway.

zanthrax

An engine burning LPG/LNG generates a lot more heat, it's generally considered incompatible with turbocharging AFAIK.

bumpstart

how does that make it incompatible?
hint hotter exhaust ( LPG when rich ) and slower burn = more energy in exhaust gas = faster spool

with its practical 102 - 110 octane ( LPG propane/ butane blends to pure propane )
there is a higher limit to ignition timing or effective compression with LPG over petrol

IE
you can push your luck with it for tune with the boost and timing compared to petrol

LPG has its losses when atmo due mainly to incorrect timing curve if dual fuel
and also due to displacing more of the inlet air due to its gaseous nature and need to burn more per unit of air to obtain the same energy
- and also the need to have a 1.5 inch Hg pressure drop for most gas mixers

under boost these losses begin to hit a wall of falling returns
and in fact , go inverse

the whole outcome is a sensitive balance of many effects

- the drop of the mixer is seen as simply a more restrictive than before inter-cooler
( mines now 75mm bar and plate , so in all the total restriction is likely lower than stock )
and its losses are still nothing like a rally restrictor that still manage very high hp

the system is fuel flow compensating with boost, and requires only the addition of a boost reference to the converter top stage
its vapor pressure fed from converter ramps up and down 1 to 1 with the boost pressure
( the closed loop controller solenoid will introduce higher vacs to lower the pressure from converter, leaning it momentarily )
- a simple and effective measure when dealing with a vapour fuel

if you toss up in the air
the 14.7 V 15.3 AFR V 1.3 in volume per energy factor
V 10 % displacement losses V timing and boost and efficiency at 102 + octane argument
it will amount to in practical cost terms, a saving 50% on the cost of operating petrol with 98 octane
( in Australian dollars and prices )

the bonuses------------

-safer higher boost at same end timing

- excellent atomisation and homogeneous mixing at any velocity or intake duty time
all with the worst of inlet manifold designs

- slow burn characteristics that suit even flame propagation across both Leading and trailing unequal chamber under compression
( the trailing spark is almost redundant )
that also suits the long torque stroke ( expansion cycle ) of a rotor

-no wet walling or boundary layer stratification to lower real efficiency like petrol
offsetting the rotors huge drawback of surface quench area in combustion chamber with petrol
( not so LPG )
in fact, the rotors large chamber turn beneficial with LPG
with LPG providing no boundary layer quench, its more robust from localised overheating than like a smaller piston chamber

- any loss in efficiency due to the burn extending beyond the expansion stroke
( due to over rich LPG ) is regained as turbo spool !
[ when in a petrol situation the over rich may drop exhaust temps ]

- rotaries have OMP , and no valves to recede, no extra wear concerns beyond perhaps increasing the OMP slightly

- rotaries have cold side inlet ( if not bridged or PP )
this makes them less prone with mixer type install to backfire than a conventional engine on LPG
- much like why the hydrogen likes the rotor

- ( and $3000 or rebates in WA, $2000 in rest of oz )


the downfall -------------

- the tank range for the discreet rx7 install
200 km of safe fanging
( my tank under floor in original location )

any losses i have
( due mainly to my particular single TB rather than LPG itself )
are offset under boost, i can run more

i have pulled down the previous engine at about 15000 km with LPG
( unknown Km before that, jap import )
no discernible extra apex seal wear, very clean, and very white exhaust
another 15 000 so far on the mild port to!
i am driving it daily !

my experience is the boosted rotor is a VERY good candidate for LPG
with many pluses and few of the normal inherent LPG downfalls
- the big practical limit is the tank size fit and placement in the coupes

NissanConvert

iTrader: (1)

I've seen more and more on gas powered rotaries. mazda has the hydrogen rx-8. i've seen some n/a 7's converted to run on something don't recal LPG, natural gas, etc. I can't remember the companies doing the conversions either. google is coming up empty. i'll look harder later, maybe come back with some answers.

seanfd3s

Keep it coming, I'm interested in this area and need to play catch up