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View Full Version : LPG Conversion kit for 79 RR



kaistuff
1st April 2005, 03:48 PM
HI

I am looking to convert my toy RR to LPG its a 79 3.5 v8 twin carbie 2 door model locking of installing it my self :twisted: :idea:
Do I need 2 converters or is it better to convert to single carbie :?:


I am also locking for some longer HD rear springs to lift the back 2"
I have from ground to mudguard 900mm with 235x84x16 MT Tyers

Thanks for all the help I will get


Kaistuff

loanrangie
1st April 2005, 04:18 PM
You dont need to change to a single carb, all you need is a pair of gas mixers that mount to each carb and the matching converter. You can also modify the original manifold to fit a holley or other 2/4 barrel carb and then use an impco/sprintgas or whatever mixer on top. Cheapest option is to fit tank in rear and put spare on a roof rack or wheel carrier.

LandyAndy
1st April 2005, 04:56 PM
Hi Kaistuff
My Bro has a mate up in Perth that does LPG conversions.He had a Rangie in with the twin carbs,apparentley he had no end of trouble keeping them balanced whilst on LPG,and said he wouldnt do another as he considered it to be unreliable,the biggest problem was it leaning out in one or the other carbs and risking valve burning.
If you can afford to spend a bit extra have a look at the new "Sprintgas" mixers,but Im pretty sure you will need the 2 or 4 barrel intake manifold and carby.
Try WWW.Sprintgas.com.au (PS this addy is from memory,if it doesnt work its easy to find with a google search)
Andrew

kaistuff
4th April 2005, 11:53 AM
Originally posted by kaistuff
HI

thanks for the help now i need to get a second hand gas kit

Kaistuff

Ralf_the_RR
9th April 2005, 06:17 PM
Originally posted by loanrangie
You dont need to change to a single carb, all you need is a pair of gas mixers that mount to each carb and the matching converter. Cheapest option is to fit tank in rear and put spare on a roof rack or wheel carrier.

Yep.
Couldn't agree more (well maybe a little).

I've got a single converter that feeds a Y piece, and then a single mixer on each carb (mine are SUs).
My petrol tank was replaced with 2 "scuba" tanks, and twin sill petrol tanks.

Runs well.
I get about 19-20L/100K on gas, and about 16-19L/100K on petrol.

I've seen others that have a vacuum lift solenoid for the carbs.
This lifts the piston up and relies on the butterfly only.
The reason is to reduce wear of the metering needle.
Mine doesn't have this setup, but I don't think SUs suffer the same problem os the strombergs. (Also the SUs don't have a diaphragm).

The problem with putting the tank in the cargo area is reduced space.
You have to weigh up what you want to do.
If cargo space is important, then external tank(s) is the go.
If not, then there are 2 options.
1. The (larger) tank goes behind the rear seat laterally.
2. The (smaller) tanks goes longitudinally on the driver side (opposite the spare wheel).

Don't know about installation costs, but running costs are great.
Tuning is not a problem, and neither are the valve seats.
I've heard that some use Flashlube (or similar) to lo lubricate the upper cylinder area. I don't.

Mine starts on gas no probs.
Idles smooth, and there is not a noticable difference in performance.

loanrangie
10th April 2005, 03:29 PM
Harry, do your sill tanks have sender units in them? I'm half way thru doing the same setup, twin sill tanks and twin scuba tanks but i would like to know how fuel is in them. Is the gas gauge a seperate one or hooked up to your in dash gauge?

RR5L
10th April 2005, 03:38 PM
Im intersted in this also, as I want to add sills to my truck. I have the twin scubas already and the 40 litres in the right rear corner.

I was thinking of using transfer pumps to the tank in the rear and keep tat as the only feed point to the engine. Fuel gauges in the sills would be nice.

Ralf_the_RR
10th April 2005, 05:00 PM
Originally posted by loanrangie
Harry, do your sill tanks have sender units in them? I'm half way thru doing the same setup, twin sill tanks and twin scuba tanks but i would like to know how fuel is in them. Is the gas gauge a seperate one or hooked up to your in dash gauge?

Both sill tanks have senders.
I have 2 vdo gauges. One for gas the other petrol.

The gas gauge sums both tanks.

I have a switch on the dash that selects each petrol tank.
When switched to left, the left tank feeds the motor, and the contents are displayed on the gauge. When the right is selected the reciprocal happens (obviously).

Effectively I can see the contents of each tank and supply the engine from either.

The original pump is maintained.
Solenoids selects the feed to the pump.


As an aside issue, the original fuel gauge is now reduntant.
I installed a VDO temp gauge, so now both temp & fuel gauges are useless.
Installed a tacho in their place. Fantastic style_emoticons/<#EMO_DIR#>/laugh.gif

loanrangie
11th April 2005, 06:43 PM
Did some searching on the net last night, saw a speco 2" fuel gauge with sender for $70 on ebay. Could put one in each sill and put the gauges in a dash pod, also saw on ebay a gas setup that had a gauge calibrater that is adjustable so you can make the lpg tank senders work with the in dash gauge. I have the same setup with the solenoid switching between tanks, its setup so that the driver side tank is the default and even if the solenoid packs in fuel still flows from that tank. Still thinking about fitting efi as well but this will complicate things unless i use the left sill as an auxillary and use the stock pump as a transfer pump to the rh tank .
That way i can plumb the one tank with return from the fuel rail . :idea:

LandyAndy
11th April 2005, 08:21 PM
Hi guys
You need an LPG specific gauge to read LPG,cant recall exactly the ratings,but the petrol and gas senders run on completely different ohms.If needed I can check tommorow wich the LPG is(1 is like 90 ohms and the other 180 ohms,but thats a guess) as I have a near new LPG VDO gauge in my 109,a working petrol gauge wouldnt work correctly on LPG.The switches that make the dash gauge read LPG have a built in conversion factor.A petrol gauge wont read correct on a LPG tank and vice versa.
Andrew

Ralf_the_RR
12th April 2005, 07:47 PM
Originally posted by LandyAndy
Hi guys
You need an LPG specific gauge to read LPG,cant recall exactly the ratings,but the petrol and gas senders run on completely different ohms.If needed I can check tommorow wich the LPG is(1 is like 90 ohms and the other 180 ohms,but thats a guess) as I have a near new LPG VDO gauge in my 109,a working petrol gauge wouldnt work correctly on LPG.The switches that make the dash gauge read LPG have a built in conversion factor.A petrol gauge wont read correct on a LPG tank and vice versa.
Andrew

Yep, you're right.
A check of the VDO website confirms this.

I have twin gas tanks, so the signals are probably summed to form 180ohms.
Can't tell. Both gauges (petrol & gas) look identical.

But definately worth considering if installing from scratch.

loanrangie
13th April 2005, 08:41 PM
There is a calibrater available to change the output to the correct ohms, but if you work out what the dash gauge range is in ohms , a simple resistor or 2 will fix that. With twin lpg tanks, set the gauge to read off the tank furthest away from the T piece. In my other Rangie, the lpg gauge was one of those led ones that fits under the dash but i kept bashing it with my knee.