Running GQ 4.2 carbi on straight gas?

[steveoo]

I am thinking of putting the patrol on straight gas just been having alot of problems with the dual fuel and petrol never works. So are there any side affects if i run the car on straight gas??

If i was to do this what type of tank have people put in there car to get better range?

steve

[PGS 4WD]

Unless you change to Gasresearch which is a dedicated gas Carby you will likely still have issues and be below peak power and economy.

Cheers

Joel

[roverrat]

I am thinking of putting the patrol on straight gas just been having alot of problems with the dual fuel and petrol never works. So are there any side affects if i run the car on straight gas??

If i was to do this what type of tank have people put in there car to get better range?

steve

yes if you do serious offroading in remotish areas you are foobar'd for extra fuel .....

and in sub zero temps gas is a right royal PITA!!

[351ciofgrunt]

I am thinking of putting the patrol on straight gas just been having alot of problems with the dual fuel and petrol never works. So are there any side affects if i run the car on straight gas??

If i was to do this what type of tank have people put in there car to get better range?

steve

I am running my 4.2 carbie on straight gas using an Impco mixer and coverter and 90L tank

You need to run colder sparkplugs and pull out some total ignition timing.

[offroader-rama]

throw a nissan 4.2 injected manifold on and a gas research mixer b2 converter and away you go (throw a turbo on while your there for good mesure lol)
by direct from gas research as a kit minus manifold for around $950 but as you have it on lpg allready you could just get the bits you need for around $650
you would run either a s400 or s440 mixer

check there site http://www.gasresearch.com.au/

[LeighMac]

I have recently gone to straight gas, just wondering what colder plugs I should run. When I asked about timing they told me I could advance the time as gas has a higher octane rating. I just filled my tanks last night after the bloody gas hit the roof at 58 cents for the first time and got 160 litres in so hopefully it should get me some kms.

[351ciofgrunt]

I have recently gone to straight gas, just wondering what colder plugs I should run. When I asked about timing they told me I could advance the time as gas has a higher octane rating. I just filled my tanks last night after the bloody gas hit the roof at 58 cents for the first time and got 160 litres in so hopefully it should get me some kms.

One heat range colder spark plugs

That is incorrect about running more total timing on LPG. Yes LPG has more octane so you can run more compression but LPG has a faster burn rate than petrol at high revs and you need to pull out 7-10 degrees of total timing. Get your dizzy regraphed to only have 15 degrees mech advance. Then set your initial timing at 10 degrees. This will give you 10 degrees at idle and 25 degrees total timing.

To be more specific LPG likes more timing than petrol at low revs and less timing than petrol at high revs.

I have just been through a long process of tuning my TB42 carbie for straight LPG and have done alot of research into it.

[cooki_monsta]

ive just turbod my carbie (no longer carbie) tb 42, straight gas is fine but im going to run about 3 or 4 tanks, already have 2 fitted.

impco or gas research are the only ways to go, being a ford man myself i am bias'd and run an impco setup into custom throttle body and adaptor onto the carbie intake (carbie ditched obv)

[turbmav]

Hey Cookie, where you putting your tanks? Iv got 1x 115L in rear on SWB. What total lites are ya after?

[PGS 4WD]

The Gasresearch is less retrictive and more tuneable than Impco by far than the impco, you get better economy and more power for less boost.

Joel

[offroader-rama]

jeol how do you find the new generation mixers for big torque v8's in patrols i have being told that the new gen is better for torque than the gas research but the gas research is better for chassing hp whats your opinion

[PGS 4WD]

jeol how do you find the new generation mixers for big torque v8's in patrols i have being told that the new gen is better for torque than the gas research but the gas research is better for chassing hp whats your opinion

LPG produces more torque at low RPM as it burns slower, this is provided you have the optimium ignition timing. In another life when I owned Gasresearch performance centre we found two things, correctly tuned the Gasresearch system made more torque and power than any other LPG system, be it Impco or Sprintgas or whatever, fundamentally as the diffuser in the Gasresearch is at about 7 degrees which is not enough to stall the air, and that it was sometimes the case that the dramatic improvement in top end of the Gasresearch gave the illusion that the torque was down, this was never the case when comparing dyno results.
It gets tehnical but the slow burning nature of LPG means more manifold reversion (internal stand off) due to the residual combusion pressure being high causing poor cylinder filling at low RPM (most noticable in V8 engines where the firing events are close together and the runners are short). The remedy was a camshft with longer exhaust duration and more initial ignition timing so there was better scavenging of the cylinder as the exhaust is open longer after intake valve open, and more ignition timing such that combustion is more complete by the time the inlet opens again.
The New Gen mixers are basically the same as Sprintgas and are typically restrictive. I remember an XE with a 378 stroker that went from 168 rwkW to 230 rwkW when we upgraded from a Sprintgas system to twin Gasresearch Carbies, on the track it went from 15.0 to 13.2 over the quarter.
Joel

[RN]

ive just turbod my carbie (no longer carbie) tb 42, straight gas is fine but im going to run about 3 or 4 tanks, already have 2 fitted.

impco or gas research are the only ways to go, being a ford man myself i am bias'd and run an impco setup into custom throttle body and adaptor onto the carbie intake (carbie ditched obv)

any pictures of your conversion?