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Costs / Effort Of A Gas Conversion

JamesBisJip

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Hey guys, I'm just wondering the approx. cost of a gas conversion for my 2001 vx s pac. Even if it's an average price, or an estimate, as I've been looking at getting a conversion fitted.
 

SS-Z LS1

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$2250 in Melbourne in mid-March on VT S1 using factory memcal setup, not the normal aftermarket one that uses the petrol only memcal currently in the car. Reason being was to take advantage of the LPG spark tables and factory add in of petrol to cool exhaust valves when under sustained load which I believe is only available with a factory LPG memcal setup (at least on VT). You can then also use a factory momentary switch rather than an add on on/off switch. Price for non-factory setup was $2000 - I believe Impco only have a few of the factory style memcal setups left for the VT.

No noticeable difference in power up top, actually a slight improvement in low and mid-range on LPG (factory LPG spark tables contribute to avoiding the normal loss of power with LPG). Uses about 20% more LPG than Petrol per km. Payback after federal rebate is 11 months (based on about 17,000km/year travel).

Suggest getting one that also uses factory LPG tune for the VX for same reasons.

Cheers
Jamie
 

bfhoon

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Best thing I have ever done... I got a sprint gas aftermarket system got change from $3500 and I would only imagine it would be cheaper now. 225,000klms later engine doesn't use any oil, engine oil is clean as even after 10,000klms and I LOL at other drivers spending $100 to fill and I spend $45.00. I also pull 10l per 100km on the freeway. Never had any petrol or any other kind of lubricant to protect the valves although I think they are wearing out now its a bit steamy in the morning when cold but once its warm it settles down. Well worth it in my opinion I'm surprised LPG never really took off best thing I love about it is your engine will be sludge/carbon free compared to petrol you only have to look at the colour of the oil, I have mates with VX with less klms and their oil after 3 to 4 thousand klms is black as yuk.
 

Jonah 101

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All I can say is $3500 buys alot of petrol, Only consider LPG conversion if you do lots of KM's. The Taxis here take 2yrs before the conversion has payed for its self and they average 60,000ks a year.

Where did this over heating valves rubbish come from? the exhaust valve gets no such cooling and they are fine so long as you dont have really lean fuel mixture, besides the air coming into the cylinder is cool, so is the lpg. In fact maybe even cooler because is really cold when is evaporates.

I put a lovato injected LPG setup into a VS ute a month ago. Beautiful system. You dont ever notice it switch from petrol to gas and there is no noticeable loss in performance.
 

JMP

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I did mine when the government was putting in 2 grand, it cost me $400 and that an included upper cylinder lube kit installed. Mine got paid of in a few months by the fuel savings and even though it is down on power slightly the engine runs nicer and as mentioned above the oil is always clean. I wouldn't bother doing a conversion now as it will take too long to pay itself off and I believe the government is changing the excise on it which will make it dearer.
 

SS-Z LS1

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Well, the $3500 system mentioned by bfhoon was clearly from many years ago, my system cost $2250 in March 2013, less the $1000 gov rebate = $1250 out of pocket conversion cost (which also included plugs, leads & air filter which were all due to be changed in any case, so another $80 saving for me)

Unleaded. 17,000km/yr @ 12L/100km = 2040 l/year. @$1.40/lt = $2856/yr
LPG. 17000km/yr @ 14.5L/100 km = 2465l/year @0.65/lt = $1602/yr

Out of pocket expense of $1250 payed back in 1 year based on annual fuel expense saving of $1254/yr.

Re Valve cooling or more correctly "engine valve seat recession protection mode", it's in the GMH factory service manual for the factory LPG system fitted to the VT Commodore, I expect Holden know something about how their factory fitted system works and why they had a certain function built into the system. Under high load conditions it injects a small amount of petrol, Petrol burns cooler than LPG, resulting in cooler combustion temperature which equals a cooler exhaust temp as it passes the exhaust valve, it does not cool the valve as such but rather avoids heating it to the same level as would be the case without the added petrol. Is it essential to have? Probably not, especially If just putting around town, but for a small extra outlay why not have it setup the same as was developed between Impco and Holden? Sure fitting an injected LPG system would be ideal but not really required on a 2001 model nor as cost effective as a mixer system.

Quote from GMH Factory Service Manual for VT Commodore LPG section:

Injector Pulse Width
The injector pulse width is set to zero in all LPG operating modes, except during engine cranking or, on when the vehicle runs in “engine valve recession protection mode”.

During engine cranking the amount of petrol delivered is determined by the engine coolant temperature and the engine crank time. The injection of petrol during engine cranking is to aid engine starting.

When operating in the LPG mode, and under conditions of high speed / high load, a small amount of petrol is injected into the engine to protect the engine from engine valve seat recession. When petrol is injected under these conditions, it is referred to as the engine valve seat recession protection mode.​
I have had ICOM LPG Liquid Injection on my LS2 for 4 years now, 160,000km, never misses a beat. Payback on that $5500 system (less $2000 rebate that was available in 2009 = $3500 out of pocket) was less than 2 years (I did about 55000km/year for the first 2 years). Picked up 5 RWKW over premium unleaded (Tune was optimised for both fuels separately) uses about 15% more LPG than Petrol per KM.

Note: Taxi's in Australia (nor company vehicles) don't get the rebate and they are also driving late model cars that likely need a much more expensive Injected LPG to be compliant, their out of pocket expenses are much higher than a mixer system on a 2001 model private vehicle that also can claim the $1000 rebate.


Cheers
Jamie
 

cjf

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Don't waste your time or money on a Gas conversion. IMO just go buy a 4 cyl if your that worried about fuel costs. I work at a gas fitting workshop and not 1 person of the 15 employees will run gas on their own vehicles.
 

RACE5L

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I've been looking at Liquid Injection as part of a VH cammed LS1 conversion im doing to save emissions red tape and lower weekly costs of running, also due to running gas for the last few years and not wanting to go back... I will be doing 30,000km plus a year and up front costs arent a concern as I just bought a VH with gas and am about to buy a LS liquid setup for cheap, only outlay really after that is install. Compared to buying 42lb injectors, fuel rails, pump and surge and do custom fuel lines, buy cats etc, it isnt a huge hit on the pocket.
 
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