Outer Limits 4x4 Board

My disco has a LPG '3 tank scuba' system. It seams to only hold 55litres.

That seams to be very small to me. What's standard?

Can I mount extra tanks on somewhere and link them to the existing system?

Also, what sort of economy are 3.9autos supposed to get. I just got 25l/100 on LPG, highway/city driving.

That is about right,

they will be a 70L tank with a water capacity of 80% of that which is 56L.
25L/100 K on a mixed highway city drive should be about right.

You can advance up the timing a bit and put a better set of plugs in it with some new leads and see how you go.

@ 25L/100k with gas from anywhere to 50c/L that makes you car about
$12.50 per 100K which is pretty cheap in real terms, same as driving a faclon.

You can add another tank and link it, there is a Y piece you need to buy that has one-way valves in it to stop the tanks filling each other up as the pressure changes last time I priced one they were $80 ish. You just put a Y piece on the filler and they fill fine. Both sets of tanks will need to be sealed from the cargo area as ususal so you would make the joins under the car.

You will have to put the tank in the cargo area, IIRC you can only have LPG tanks between the chassis rails if they are underneath the car. (utes are an exception to this I think - F-trucks etc)

I have a few tanks around that might be able to help you even if you wanted to swap the scubas out, PM me for more info

Tom

Hmmm

I have the scuba's in the cargo area now, which is OK, but i'm used to having 80l usuable gas. I was thinking about running an extra one or two small scuba types in the cargo area beside the existing tanks.

Do you have any small ones that could do that? I don't really want to jeapordise cargo room too much.

I can't see anywhere underneath withour removing the petrol tank.

What should I run the timing at and what plugs and gaps do you reccomend.

Adding another set of scubas would be the best bet, if you come across any of these in Brisbane area let me know I am chasing a set too that would give you near 110L usable and you can build a platform over them.

As for plugs there is a thread on that exact subject in this section which we should really add to faq. I might organise that.

NGK BP6RES gapped to .7mm

As for timing, it would be a bit of guess and check, aparently they like 12 degress before but that makes fuel ping, I am about to start mucking around with this and find out what works best for my car I would start at 6 degrees and see if fuel still works ok and then go 1 degree at a time to find the sweet spot. Someone correct me if you have the exact figure pls.

Tom

My carbed lpg 3.5 low comp is happy at 12 btdc on gas and petrol.

Doesn't it make better sense to ditch the scubas and install between wheel arches a tank say 990 long by either 360, 400 or 440 (I think). This gives capacites of 86L up to 104L.

Thats my option when I go gas shortly. Also will build floor over top with 2 drawers in front of tank each about 300mm deep.

Silverhammer

A tank of that size in a disco will give you fa room left, the false floor will have to be the same height as the cargo blind - no point having a wagon it you cant put anything in it. At least with a classic rangie you can fit a tank along 1 side and still have room for gear. Still the best option is underfloor twin tanks of 70 litres useable and either a pocket tank (35-40ltrs) or sill tanks.

I have the 3 scuba tanks in my Disco and the most gas I have ever put into them was about 66 ltrs.

They are a pita re not enough boot space but its nice to keep the standard petrol tank

Dragonwagon

Dragonwagon
What supplier for 3 scubas? I'm only aware of twin scubas.

Also, out of interest, what brand mixer etc? What sort of eceonomy & performance impact on gas?

I agree re keeping fuel tank...a long range tank is mega bucks, probably half of a gas install.

Silverhammer

Tank is labelled as A.P.A model no G84man

Mixer,converter is Impco

Runs smoother on LPG than ULP, but petrol seems to have more grunt

Its a V8 Disco so we dont talk about fuel economy

On the highway I can get up to 300km out of a tank of gas, but only about half that off road

The tanks are approx 250mm dia and sit under a carpet trimmed plywood false floor in cargo area

Vehicle has gas on when we bought it, we have done about 36k since then & have not yet had to touch any gas or ignition bits yet, has been very reliable,only one backfire when converter froze (my fault,airlock in coolant hose)

Paid 32.9 for lpg today,so kind of cheap to run for a 4x4

Cheers Dragonwagon

Thanks for the info, Dragonwagon. LPG is priced 57-64c/L here (Hobart).