Outer Limits 4x4 Board

hey guys i have a 4.2 petrol/gas and im gettin sick of it runnin like shit so i have decided its 1 or the other!! just wonderin what r people thoughts on runnin straight gas 2 petrol!! its carby at the monent but if i go with straight fuel ill inject it!

any help would be great thanks

Straight gas it

cheaper than petrol, if tuned properlly you will get good economy (i have 450-500K's around town and over 700K's on the Freeway to 100L of usable gas). Power well that was also good, turning 35" rubber up some of the steep hills on the F3 Freeway near the Central Coast (Mooney Mooney Hill and the Ourimbah to Kariong Hill) and i was doing it in 4th at 110K's no worries,

how much did it cost u 2 convert it 2 straight gas????

just take the fuel off n get it tuned,block of wat u done need

i never got to the full setup before i rolled the car :(

but i got this far

Get a EFI Prelum chamber and plug all but one of the big vacuum ports (for the brakes) and 1 for the Dizzy advance.

Then you need to have teh EFI throttle body (butterfly) to control the intake of the gas, also make sure to plug up the injector ports so no gas escapes from there.

You will also need to get an EFI based mixer that connects into the intake tube.

u can get away with it for around $600

Da Danga wrote:hey guys i have a 4.2 petrol/gas and im gettin sick of it runnin like shit so i have decided its 1 or the other!! just wonderin what r people thoughts on runnin straight gas 2 petrol!! its carby at the monent but if i go with straight fuel ill inject it!

any help would be great thanks

a duel fuel patrol can and does run well on fuel and on gas.

if you cannot get it running right yourself, take it to someone that can.

your main problem is more than likely ignition.

also, no way in the world you will get 700km's to 100lites of gas in a patrol. It is impossible.

there are countless posts on this but you do a few things to get it running right

kit your converter and mixer.
kit your carby
increase compression by shaving the head.
get electronic ignition and quality leads,
run premium unleaded to help cope with extra comp
and get the gas tuned on a dyno.
get your cooling system in tip top shape
fit extractors and a 2.5 inch exhaust.

cheers,
jes

MyGQ wrote:i never got to the full setup before i rolled the car :(

but i got this far

Get a EFI Prelum chamber and plug all but one of the big vacuum ports (for the brakes) and 1 for the Dizzy advance.

Then you need to have teh EFI throttle body (butterfly) to control the intake of the gas, also make sure to plug up the injector ports so no gas escapes from there.

You will also need to get an EFI based mixer that connects into the intake tube.

u can get away with it for around $600

the gas research tbi butterfly is 440

i had the carby rebuilt be4 christmas and its already stuff!! i got a gas guy 2 tune it last still runs like shit!! its got extractors and a 2.5 exhust and electric dizzy! coolin system is workin good!! leads are brand new!! its only mainly really bad on idle!!! doesnt really wanna idle sometimes!!! do u know any1 in sydney whos really good at tunein gas/petrol????

Allthough you cant make as much power duel fuel it is possible to get satisfactory performance from duel fuel with a TB42 carby engine, there are certain things to do to make it right though. What specifically is the problem?

Joel

it wont idle right on gas it coughs and so on!!! and now the carby is stuffed is wont even run on fuel!! im not 2 fussed about power i just want it 2 run right

Joel,
What would it cost to get a gas system checked over and tuned at your workshop? i've got a tb42 on gas that runs like crap and is quite gutless. i'm getting sick of it
-Calvin

If idle quality varies on LPG a lot it may be the mixer isn't sealed properly to the petrol carby. Coughing on acceleration is either very lean or an ignition problem most likely. Honestly it sound like it needs all the basic tune stuff to start with. Low resistanec leads, spark plugs, small air gap rotor, preferably a high energy electronic ignition, or at least point and condensor, tappets and a dyno on LPG then sort the petrol carby issues. They are a good carby and usually the issues aren't that big.
If the petrol dosent run at all then the petrol lock off may not be opening, the fuel pump stuffed or the needle and seat jammed shut. If it runs but floods it could be the float has a hole, the needle and seat stuck open, the accelerator pump check valve stuck open.

Joel

i just put new plugs and leads in it!!! do u know any1 good in sydney that could sort it out 4 me!! any1???

Sorry I dont.

Joel

fair enough if any1 knows it would be good!!! thanks 4 the help so fair guys!! so pgs 4wd do u reeckon im better of stayin with the duel fuel???

I worked with LPG for 10 years in the performance industry at GasResearch and straight gas is better provided you can get the range you want. Thats the main factor I found and I've gone to petrol only on my comp car from gas only for that reason only, petrol goes in a can and is more available.
Joel

if i was 2 go fuel i would get a injection set up cause i hate 4wdin with a carby!!! power isnt a major problem although it would need a bit cause im runnin 35s on stock diff gears!!!

PGS 4WD wrote:I worked with LPG for 10 years in the performance industry at GasResearch and straight gas is better provided you can get the range you want. Thats the main factor I found and I've gone to petrol only on my comp car from gas only for that reason only, petrol goes in a can and is more available.
Joel

gas is better but you went with petrol?
tsk tsk tsk. forklift bottles are very portable!

Jes

gas is better but you went with petrol?
tsk tsk tsk. forklift bottles are very portable!

So how does that work? Do you just unscrew one and put the othr one on? How do you fill the spare tank? Where do flies go at night???

ShaneGQ wrote:

gas is better but you went with petrol?
tsk tsk tsk. forklift bottles are very portable!

So how does that work? Do you just unscrew one and put the othr one on? How do you fill the spare tank? Where do flies go at night???

you fill the forklift bottle at the service station
you unscrew the forklift bottle, unclamp it and remove and replace with the full one.
Have you ever seen a forliftt at a servo..hehehehe

How do you get the forklift bottle LPG into the GQ engine?

I didnt say

gas is better

, I said straight gas is better, as compared to duel fuel. Straight petrol will make more power than straight LPG as LPG takes up more space in the manifold and port being it is a vapour not an atomized liquid. You need larger ports and valves to flow the same quantity of LPG/Air mix as Fuel/Air mix as petrol is denser(takes less space, fit more in). You also use more LPG to make the same amount of power due to the lower BTU valve per litre of LPG.

Joel

dansedgli wrote:How do you get the forklift bottle LPG into the GQ engine?

errrm am i missing somthing here?
You need an lpg kit in the truck first.

Jes

jessie928 wrote:

dansedgli wrote:How do you get the forklift bottle LPG into the GQ engine?

errrm am i missing somthing here?
You need an lpg kit in the truck first.

Jes

If you are using a forklift bottle as a Jerry can how do you connect it to the standard LPG system?

Or are you saying you should convert the 4wd to the same system as on a forklift so you can just replace the tanks?

dansedgli wrote:

jessie928 wrote:

dansedgli wrote:How do you get the forklift bottle LPG into the GQ engine?

errrm am i missing somthing here?
You need an lpg kit in the truck first.

Jes

If you are using a forklift bottle as a Jerry can how do you connect it to the standard LPG system?

Or are you saying you should convert the 4wd to the same system as on a forklift so you can just replace the tanks?

hi mate,

the only thing different on a forklift gas system is the fitting at the end of the flex pipe from the converter. It has quick release fitting. the rest is the same as a car system.

JEs

I used to do truck loads of LPG only conversions and pull out the fuel system, I had a fork bottle and connector hose that screwed to the normal filler. Its good for emergencies but you can't leave it connected while you drive. The bottle wont empty into your vehicle tank though, it will only empty till the pressures equalize, which will be about 1/2 the bottle contents. When you run out of LPG again you can repeat the process each time getting about 1/2 the LPG from the removable bottle, unless you have a 20 year old LPG tank in your car with bleed valve to drop the pressure in the tank.
Its necessary to have a fixed mounting for the tank and if you want to comply with LPG regs you'll need a tank with an electric lock off, overpressure valve and excess flow valve if you connect it in a way that you can drive with it connected.

Joel

Is it legal to put an LPG tank in the cabin? It would go behind the 2 front seats in my SWB if I did it.

dansedgli wrote:Is it legal to put an LPG tank in the cabin? It would go behind the 2 front seats in my SWB if I did it.

yes it is legal

It is legal provided the valve box is sealed from the cabin and vented to atmosphere, just as is the case with in the boot, all gas lines and wires go through the venting hoses to outside the vehicle.

Joel

Cool, thanks for that.

Another tank would solve the range issue. That would be the end of sleeping in it though