Outer Limits 4x4 Board

be nice to see some lpg tech filter through

my suggestion is a 60lt + spare tyre size lpg tank where the original is.

Should have good clearence and plenty of space.

Alternatilvely you can rig up a set of scuba's

i am just curious about how well the 3t will fit in the sierra engine bay and will you need to move the t/case

Whats the Net gain out of all this going to be ?

want33s wrote:Has anyone fitted LPG to a Sierra. Where did you put the tank?

I haven't fitted LPG but I looked at a SWB that had been converted for Cape York.
It had the standard tank in the useual place + a full width LPG tank in the back just in front of the tailgate...it almost had room left over to carry your lunch!

I've seen one that has the tank mounted where the fuel tank normally goes. With the clearance left it would be lucky to drive over a house brick

Guy uses it to tow a boat mainly, he reckons it's good. If I was you though I'd go EFI.

i don't think the forklift bottles would be suitable, fro memory the have to be removed to refil, this is to stop lpg emmisions inside a enclosed warehouse. Most space conscience lpg falcons or commodores either ran 3 small skinny tanks in parrallel or one wheel shape tank.

Lpg gets a bad rep on account of it often giving poor milage in a dual fuel vehicle. This is because the vehicle is set up for petrol. Since lpg is already vapour you can get a more completely combustion, and if you take advantage of this you can get better yield per tank

Sweet thing about gas carbs is that they flow the ratio of gas to air regardless of how much air passes. That and the octane rating allowing way more advance.

My suggestions if you do go ahead is

1) remove the head and get it (or the block) decked to raise that compression up and above 9.5 (depend on clearence) I don't like the idea of decking petrol engines as it throws out the tuning but in lpg case it's beneficial cause you can run a lot more advance so being slightly ahead at the front is ok.

2) Find out if your engine can take unleaded without lube. I know japan went unleaded before us and that makes suzuki engines fine but if your toyota motor was assembled in australia chances are you will need hadened valve seat installed while the head is off.

3) Find a throttlebody that bolts into your intake. The usual thing is just use the petrol carb but it is probably way more restrictive than just a straight valve (not to mention tidies stuff up considerably)

4) once installed get it dyno tuned, should be quick as all they got to do is timing

This should maximise the bang per buck, you can do it cheap but don't cut all the corners... your a pioneer after all

want33s wrote:

flyinwall wrote:i am just curious about how well the 3t will fit in the sierra engine bay and will you need to move the t/case

I reckon I could get away with the stock transfer position if I radically shorten the jackshaft. I'd rather not move it back if possible as tailshafts are not cheap. I want to raise the transfer about 25mm so its above the bottom of the chassis. Did you get your lux springs in the rear? How much did it move your diff back?

i didn't end up putting the lux springs in the back just left the standard ones in there will see what happenens in the future though

If I were to LPG a sierra I would use a donut LPG tank. This tank is designed to fit into the spare tyre location of cars. Hence the size of the tank would the same size as a tyre.....You mount this on the rear floor between the wheel wells and buid a false floor over it......

Or you can use the scuba LPG tank setup as per the BA falcon wagons...I don't know size but these would be fairly thin but take up a little more room than the donut tank........

Donut tank hold 64ltrs usable
scuba tanks hold 107lts usable

It all depends on how and where you want to mount the tank and how you want to use the car later.....

Have run LPG powered cars for 12years without incident........even getting my new car converted in a couple weeks......

You have to think that 64lts usable in an XF Falcon 4.1lt 6cyl gets me near on 350kays......

64lt in a zook would get you about 450kays if not more.......me thinks

There is no way you fit a 100lt tank on a zook without filling the back of the car up.....

Donut tank may fit in between chassis below floor but you will have to modify the shock cross member as I have done to fit the vitara tank in the back of mine.....

donut tank!
(here i'm trying to describe spare tyre shape tank thingy)

i saw a truck today with the tank mounted along the side under the tray.

Since the tanks are designed to stand up to the impact of a crash i guess it's legal, might be worthwhile going to a gas fitter and asking, look kind of sweet with a 'torpedo' on either side . (heck paint hem green and add military markings)

I have a sierra that run on straight LPG for 4 or 5 years. Tank is under the rear with plenty of clearance. Runs like a dream at any angle.

Joe