Brumby LPG conversion

smiles · Post by **smiles** » Fri Feb 26, 2010 12:58 am

I went to an LPG mechanic today to discuss the options for gas tank installation under the tray of my Brumby.

The best way to go seemed to be to put a doughnut tank in the current petrol tank location and put a smaller petrol tank in the space behind the cab bulkhead underneath the tray.

This is going to be expensive so maybe I could save some money by either sourcing and installing the smaller petrol tank myself, or fabricating one.

So my questions are: What can we legally build petrol tanks out of (is fibreglass allowed)?

and has anyone installed a petrol tank from another vehicle in the space behind the cab under the tray?

brumbyrunner · Post by **brumbyrunner** » Fri Feb 26, 2010 8:17 am

i don't think you can build petrol tanks from fibreglass

But alloy, stainless & mild steel get used all the time. Pros and cons for each. It's no big deal, it's just a box with some baffles and barbed tails welded on. Biggest headache with fuel tanks is mounting them securely and filling them up.
Why not put a gas tank in the well behind the current fuel tank?
Pity you're not a bit closer, I've got a complete gas setup I don't want.

steptoe · Post by **steptoe** » Fri Feb 26, 2010 8:31 am

I was gonna suggest an old LPG bottle as a fuel tank - but still really needs engineer certificate. Another suggestion I forgot was maybe try to source a used but recerifiable scuba tank from Falcon wagon/sedan that could fit giving lower profile and centre of gravity ON the tray. I went straight gas on both Brumbies and rarely finding I need al the tray. Long term the savings outway inconvenience or cost of borrowing trailer say for motor bikes. Gees, in just a year I reckon I saved enough to buy a new medium to heavy duty box trailer. 80 litre useable in one, about 72 in the other - safe for 500km push 600......then I'd need a push! Going straight saves components needed to buy fit maintain. Many installers would say go dual fuel just in case something stuffs up - to save their arse and the name of LPG. Four cars and twenty years I never had LPG component failure.

steptoe · Post by **steptoe** » Fri Feb 26, 2010 8:35 am

Donuts are pricey. Scour wreckers for posible supply of good used tanks in date or been checked if over ten years. Checked are stamped again on tank ID plate with a symbol like a 18 kg tall BBQ bottle outline with inspectors 3 digit number within and new date like 02 10 either side of logo and wiped with gold paint. 10 year inspection worth about 150 bucks to 250 if a one housing holds all four valves arrangement - out of car fee

smiles · Post by **smiles** » Fri Feb 26, 2010 8:49 pm

Apparently there is not enough room behind the petrol tank for a gas tank... the biggest tank that will fit in there after taking the petrol tank out is a 50 Litre doughnut tank. I guess that might make the long trips a bit difficult if it was dedicated LPG..

smiles · Post by **smiles** » Fri Feb 26, 2010 9:02 pm

So I'll probably just go with a 60 litre tank in the tray and keep it as dual fuel, as this seems the cheapest option by far.

smiles · Post by **smiles** » Sun Mar 07, 2010 4:57 pm

Well I got the system installed, and now the mixer ring has lifted the stock air cleaner too high for the bonnet to close flush. The mechanic "fixed" this problem by raising the round rubber stops and putting a couple of washers between the catch and the bonnet. The air cleaner still hits the bonnet though and has taken paint off. Now, for the pit inspection so I can get my $1750 rebate I'll have to decide if it is more likely to be rejected due to the raised bonnet and air cleaner rubbing, or a non stock air cleaner with some of the original vacuum lines missing... I hope the fuel savings are going to be worth the mess they made of my car! Anyone else had this problem? And Steptoe- Is your system open loop or closed loop?

Matt · Post by **Matt** » Sun Mar 07, 2010 6:23 pm

Sorry to steal the thread Smiles, but Brumby Runner, how much would you be after for the system? I more then likely wouldn't be after the tank, probably just everything else as i am looking at doing the same thing but with full time lpg with a couple of smaller tanks plumbed together as i need the tray space.

sven '2' · Post by **sven '2'** » Sun Mar 07, 2010 7:18 pm

smiles wrote:Well I got the system installed, and now the mixer ring has lifted the stock air cleaner too high for the bonnet to close flush. The mechanic "fixed" this problem by raising the round rubber stops and putting a couple of washers between the catch and the bonnet. The air cleaner still hits the bonnet though and has taken paint off. Now, for the pit inspection so I can get my $1750 rebate I'll have to decide if it is more likely to be rejected due to the raised bonnet and air cleaner rubbing, or a non stock air cleaner with some of the original vacuum lines missing... I hope the fuel savings are going to be worth the mess they made of my car! Anyone else had this problem? And Steptoe- Is your system open loop or closed loop?

Short answer no...sounds like you've been had.

This situation has a roof installation feel to it. There will be a LPG fitters association in WA, maybe a spinoff from the the MTA - be a good place to start with resolution if no joy with the installer.

There are plenty of Brumbys around with LPG without this problem.

Goodluck

Sven

steptoe · Post by **steptoe** » Sun Mar 07, 2010 9:54 pm

Good component suppliers (the wholesalers) usually know the spud in mixer ring adds too much to the air filter height. Same wholesaler that told me this also gave me wrong spec throttle body to use bleeding air past loose fit blade giving a warm idle of 1500rpm !!

Open loop. AS1425:2003 says closed loop is only required on vehicle running O2 sensor, so the big Landcruisers that are efi mothers but not run an O2 sensor go the easy no control boxes to stuff up open loop - or fresh air system

Sneaky spacing between engine cross member and body will give some air box clearance. I just used a few fat washers from hardwre joint to get some clearance of a threaded boss on 5 speed touching tunnel. It may give you some relief.

They fitted positive pressure system that used the spud ring. I use the neg presure Impco J and 125 mixer (you can find diagrams on http://www.teecoproducts.com download the master catalogue for impco or just bits, total is 12MB?)

In the crudest form that vapour hose can or can almost be fitted up to feed straight in to the air box inside the filter and still perform like the old crapper taxis used to be ala XF Falcons

steptoe · Post by **steptoe** » Sun Mar 07, 2010 10:09 pm

MAY NEED TO GOOGLE teeco products, that may not be correct web site above.

Hold the mechanic to getting the job done right, consumer rights and all that sort of thing. The AS1425:2003 also requires a tank guard made of steel sheet with a thickness of half that of the tank wall. 1.6mm sheet is good to use. Don't go all blazing at him - yet.

These conversions do not come as a kit like all newer models need to so as to comply with emissions standards - more as components to fit and juggle, tinker and modify.

eg my EA82T I run a VN commodore style air box upside down and using fittings from LPG suppliers to vent rocker cover hoses to air box, left and right and the vapour bleed hose from charcoal canister, using just heater hose that can go gooey in a few years time.

Twin carb Brumby has 100 x50 steel box with ends capped sits atop twins. Hole in front connects to exhaust pipe and silicone fittings to a horizontal mounted 125 mixer 450mm away from carbies. This mixer gets air from VN air box mounted where canister and jack used to be.

Single carb Brumby was a nightmare to graft a efi throttle body to other bits to sit mixer atop manifold like a petrol carby, I do se why using mixer ring instead of mixer carb was chosen method but someone gotta do some more thinkering to sort your concerns

steptoe · Post by **steptoe** » Sun Mar 07, 2010 10:16 pm

Umm, dare I ask where someone fitted the fill valve??

steptoe · Post by **steptoe** » Sun Mar 07, 2010 10:18 pm

Maybe if the air box hits the bracing of the underside of bonnet, some careful surgery may give relief?

smiles · Post by **smiles** » Sun Mar 07, 2010 10:43 pm

Thanks for your response. It was idling really high today once it got warm so I am suspicious of the ring fitment now. I turned the power screw in which solved that and also solved the backfiring issue, but I realise I'll have to be careful about running it too lean...

The filler valve is at the back under the tailgate aside the number plate where I asked for it to go.

smiles · Post by **smiles** » Mon Mar 08, 2010 12:03 am

And I'll do what you suggested Steptoe with the engine crossmember. That's exactly the solution I was after- thanks!

smiles · Post by **smiles** » Mon Mar 08, 2010 12:05 am

Eventually I'll stick a round air filter assembly on the carby. It looks like I'll have a bit more clearance that way.. but not till the pit inspection is done.

smiles · Post by **smiles** » Mon Mar 08, 2010 2:33 am

Anybody know where I can find this online: AS1425:2003 Rules for Lpg vehicles? I was told I could build the gas tank enclosure from any material and I want to know if this is true. Thanks

steptoe · Post by **steptoe** » Mon Mar 08, 2010 1:03 pm

NOT online as it is a buyable product. Cannot find it in me mates shop as he is in the middle of a clean and now accuses me of losing it, coz he can't read! I will find its words later for you

steptoe · Post by **steptoe** » Mon Mar 08, 2010 1:12 pm

http://infostore.saiglobal.com/store2/r ... ch=Proceed

http://www.standards.com.au http://www.standards.org.au

steptoe · Post by **steptoe** » Mon Mar 08, 2010 1:42 pm

Gee's , No one told us the standard had been updated

AS1425:2007

So, from AS1425:2003
SECTION 3
ITEM 20

3.20 PROTECTION

(a) Each container shall be located in a position, or provided with protection, such that damage in the course of normal vehicle usage is minimised. In particular --

(i) locations vulnerable to impact by objects thrown by tyres shall be avoided;and
(ii) damage due to impact by objects being handledby or carried by the vehicle shall be prevented

luggage space of passenger car is exempt

ahhh! The 1.5mm steel plate guard specs being quoted within the industry is for under vehicle mounted tanks . Interpretation is a big thing. But not a bad guide to go on for users safety and that is what it is all about.

I wish I could find the photos of LPG cylinder sitting alone on the road - 50m from the car in which it was mounted only minutes before the PRX valve thought to be faulty caused things to BLOW!!

AS 1425:2003

3.20
(e) A fuel container which is below the floor of a vehicle shall be provided with a guard to protect against ground impact when ground clearance of tank is less than 300mm, or vehicle is less than 4.5t mass, or whole of container mounted behind centreline of rear axle

The guard shall be at least equivalent to a 1.5mm steel plate guard, arranged to shield the silhouette of the cylindrical portion of the container

1.5.37 Shall, indicates that a statement is mandatory

In a nutshell the latest standard AS1425:2007, that I have not, is what your install is governed by. 1.5mm is a good guide to go by