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Old 21-09-2009, 12:35 PM   #1
RianScott
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Default DIY LPG and how I did it

Trikky2 suggested I did a write up on how I converted my 2l 76 bay to run on LPG. I have seen many write ups on other forums but a search on LPG returns nothing on VZI (I think thats a forum problem rather than there being nothing on there , or I can't manage to do a proper search!) so here goes..

Total conversion cost 650
certification for safety and insurance purposes 35

I have a 2 litre 76 bay that breaks down on every motorway he has ever been on and before I start please may I state that all I say is opinion and open to suggestion, if you are not confident then seek further advice or get it done by a pro (and make sure your van is running good before you start (unless you're like me and just wanna get it done and sort out the original probs later )) i DO NOT TAKE ANY RESPOSIBILITY FOR YOU BLOWING YOURSELF UP! I AM NOT A QUALIFIED LPG INSTALLER THEREFORE CAN ONLY DETAIL WHAT I DID, RIGHT OR WRONG.

STEP 1: Get yourself a copy of the cop 11 regulations! very important, these regs are not the law but bloody good advice! read them and then read them again!

STEP 2: choose your kit supplier and figure out what type of kit you require: my system is an open loop system 70l upright toridal tank with twin mixers because I have twin solex but you may require single mixer.

STEP 3: Decide where you want to locate your tank, under the bed? above the spare wheel compartment?, this will determine the type of tank you will need and the size you can fit in. When deciding on tank size then obviously the space you have will determine this but go for the biggest you can fit in. the tanks generally hold (as a safety measure) 20% less than they state so a 70l tank will hold 56 litres, you generally get a few less mpg than on petrol due to the nature of gas so figure out carefully the distance you will be able to go before needing to fill up. having to switch back to petrol cause you are miles away from an LPG vendor will gut you let alone eat into your payback time!

STEP 4: measure your carb(s) mouth (where the air filter fits onto the carb, measure this to the millimetre and pass these details to your kit supplier so they can provide the correct mixer(s) with your kit

STEP 5: order your kit and fit it!

If this thread becomes popular I will add more details but I may well make the installation sound like childs play but please don't think for one minute that there won't be grazed nuckles and the like, I just tend to forget the bad times and smile everytime I fill up! so don't be suprised if I suddenly say later on in the thread "oh yeah, I had that problem too!"

Basically the kit contains:
1: your chosen tank and cradle
2: vaporiser (that turns liquid gas into low pressure vapour for your engine to suck in
3: mixers (which sit ontop of your carb(s) and allow your engine to suck gas from them and air from your standard air filter)
4: some copper pipe covered in pvc (2 sizes , the larger bore is for filling and the smaller to feed the system
5: rubber LPG Fuel pipe (that goes from the vaporiser to the mixer(s) on the carb(s)
6: compression type gas fittings which with the aid of a spanner allow all your joints to be leak free
7: power valve (that sits between your vapouriser and carb mixers in the rubber pipe, this controls how much gas vapour you allow your engine to suck. bit like your mixture screw on your carb)
8: a couple of solenoids (electrically operated cut off valves for gas and petrol)
9: control switch and fuel gauge for your cockpit
10: wiring loom (mine wasn't long enough on a few wires so might need adjustment cause unlike most cars, the engine is a good way from the cockpit but on the other hand, unless you have the tank in the cockpit your pipe work won't have to run as far as in a normal car!
11: Some ducting (for running pipes and electrics through and for venting)
12: detail instructions (well I did from my supplier! and a help line)
13: Exhause probe (for heating the liquid gas so your vaporiser doesnt freeze up because you dont have water in aircooooooled) these are are a bit of a grey area in respect to the cop 11 regulations and there are rumours of mini water system being used but the suppliers of these systems won't even respond to you emails unless you are a trader LPG installer so I wish you better luck in finding info than I managed to get!
14: probably some other bits that I'll remember as I post more details.


first I fitted the tank, 70l upright toridal (which you will pay a little more for)mine sits just above the original spare wheel well as shown in the pic, as my spare is on the front of the vehicle with a chalk board on the front that the local kids take great joy in writing rude words on (I like it really or I wouldn't leave the chalk out!) DONT FIT YOUR TANK FIRST LIKE I DID! thats what I learned, figure out where you want it put the cradle in , make brackets out of an old stairlift if you need to (as I did) but dont bolt the tank in place till later or you will be unbolting it again and again.
http://www.voltzwagon.co.uk/dusty/lpg/tanklocation.JPG

more coming, I just wanna check that the pics work

Pics work (a little large I agree but hey, at least you can see whats going on!)

after fitting the tank, I wen't along the route of fitting everything else except the pipe work and wires because you wouldn't know how much pipework you needed until you have the main components in place.

so next I fitted the vaporiser inn the engine bay on the left bolting it to the spare wheel well, just above the vaporiser and nearer the back of the vehicle I bolted the lpg cut off valve to the spare wheel well. you can see these in the huge pic
http://www.voltzwagon.co.uk/dusty/lp...dandvapour.JPG

then I fitted the mixers on the carbs, they just slip on top of your carb (if they are the right size!) and then you pop your airfilter on top of the mixers simple! (or maybe you try to sit them on top of the carbs, figure that they are too small, get supplier to send 2 new ones a few mm bigger, then realise that the arms on your airbox that feed the air are to low to then fit ontop of your mixers because of the raised height and so chop off the bottom of your air filter arms badly with a hacksaw and then use high temp silicone to seal until you think of something better see pics )
http://www.voltzwagon.co.uk/dusty/lpg/rightmixer.JPG

Then get a hole cutter and desicrate your poor bay for a new filler, somewhere strong to resist the pressure you put on when twisting the filler pipe on at the garage. Remember, the shorter the run from filler to tank, the quicker the fill at the service station, so get your filler as close to the tank as possible,

heres a couple of pics of the filler inside and out, just as a note, I made life easier for myself by making sure the filler backed onto the engine bay, if it backs inside the living quaters then you will need to add venting pipes and the like on the filler to make sure that if there was a leak during filling that when you get into your van it aint full of gas!
http://www.voltzwagon.co.uk/dusty/lpg/gasfiller.JPG

http://www.voltzwagon.co.uk/dusty/lpg/backoffiller.JPG

more coming, I'm just paranoid about this computer crashing!

sow now the tank filler is clamped in (use a bit of silicone arond it before fitting to prevent the new edge from rusting)

Next bolt in the petrol cut off solenoid, I placed mine right at the back firewall to the right (where my fuel pipe came up)

http://www.voltzwagon.co.uk/dusty/lpg/petrolcutoff.JPG

and then last but least of the main components, the exhaust probe, it's about 12 to 15 inches long. you drill a hole in the side of your exhaust, my exhaust may be different to yours so make your decisions where you think it may fit, mine is shown in the pic, i managed to get it on the left of the exhaust running along the length. simply drill a hole about the same size of the probe, weld the little boss nut to the exhaust and then insert the probe through it and clamp it up! (Or drill hole in exhaust, make it a little bigger, cause the probe won't fit in cause your masonary drill aint really the tool for the job, then resort to angling the drill left and right, up and down till the hole is then big enough for the probe, slide in the probe only to realise exhausts contain baffles and these need to be drilled too. only 2 baffles in mine it seems thank goodness ! slide the probe in, it's a nice tight fit with no ratttles hoorah! bolt it up)

http://www.voltzwagon.co.uk/dusty/lpg/exhaustprobe.JPG

now there are probably other bits to do on main components but I'll edit as I think about them.

so before we do the pipework lets figure out how this system works and then we can figure out where the pipes go!

so you fill your van with LPG so that means the 8mm pipe needs to run
FROM your filler to your tank, easy!
Then the liquid gas has to come from the tank and be heated but really just incase something was to go wrong with the exhaust probe then you want to go through the LPG shut off vavle first. 6mm pipe from now on
SO FROM the tank TO the shut off valve,
FROM the shut off valve TO the exhaust probe to heat the gas,
FROM the exhaust probe to the vaporiser

AFTER the vaporiser, we move into the rubber LPG pipe because we are dealing with low pressure gas vapour, not Liquid gas

RUBBER pipe from vaporiser to the the carb mixer(s) one or two depending on your carb setup
Now we need a way to control the amount of gas the carbs suck in so you have a power valve which just jubilee clips between the vaporiser and carb mixer (before the pipe splits on twin mixers) its just a screw in valve really that restricks the amount of gas you can suck:

Bingo, thats how it works:

now for a few more pics and details:

see more below cause it wont let me put any more in this bit!

Last edited by RianScott; 23-09-2009 at 11:32 AM..
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Old 21-09-2009, 12:47 PM   #2
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good work, I'm sure this thread will prove to be popular.
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Old 21-09-2009, 12:55 PM   #3
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removed this bit further up

Last edited by RianScott; 21-09-2009 at 01:18 PM..
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Old 21-09-2009, 12:56 PM   #4
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Wow that was quick

Nice thread. Just reduce the size of your pictures to 800x600 pixels or a bit less so they fit on the screen better. I think you may be able to do this in photobucket itself.

Thanks for the write up - looking foreward to seeing more pics.
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Old 21-09-2009, 01:03 PM   #5
RianScott
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I'll reduce the pic sizes in a sec, hold on.........


There we go, no more scrolling!

I guess I should edit the original post rater than keep posting after everyone else posts, I'll try and move it all up .....


good now I'll carry on up above ..........

Last edited by RianScott; 21-09-2009 at 01:19 PM..
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Old 21-09-2009, 02:08 PM   #6
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It says my previous post is too long so I'll continue here

before we go any further, its easier for me to explain the venting system rather than as we go along. LPG is heavier than air. rest assured your tank is a sealed unit even where the connections of the pipes to your tank are in a gastight box (mine are in the middle of the upright donut tank with a vapour seal screw on cover, the tanks are much safer than petrol tanks but I guess at the end of this conversion you still have a petrol tank so you may have increased any risks slightly. the tank is going inside the van, whether you like it or not, from what I have read, you don't have the clearance underneath and there is bugger all else places to put it unless you put it on the front of the van like a spare wheel and I think you and I know that aint a good idea even if it were legal! so you have decided to put the tank in the van so that means all pipes and electrics to the tank need to run INSIDE the plastic vent pipes that jubilee clip onto the tank (and a bit of silicone sealer to make sure its gas tight) I used gas flue sealer because it's temperature resistant and what I had lying around)

So any pipework that comes from the tank must be vented to the outside world and that means OUTSIDE, not into the engine bay but somewhere it could blow away if there were a leak.
so to get from the filler to the tank in my instance, I had to go FROM the filler to outside the van (just behind the rear wheelarch) and then back up through a vent pipe. That means that the other way round from the tank the pipe runs down a vent pipe to the outside world (back of the wheelarch) then back up to the filler. is this neccesary? well I feel safer and is how I read the cop 11 regulations.
Now the pipe to feed the exhaust probe (through the lpg solenoid (shut off) needs to go from the tank, down one of the the vent pipes (there are two vent pipes on my tank), through the enginebay floor (back of the wheel arch) and then back up to the lpg solenoid.
all the pipework inside the engine bay doesn't require venting because thats where it all happens but it is important I understand to get those vent pipe from the tank to outside. a full tank of gas in the height of summer may vent a little and you don't want that IN your van or IN your Engine bay so OUT is the answer.

Heres the vent pipes going through the spare wheel recess
http://www.voltzwagon.co.uk/dusty/lp...heelrecess.JPG

and from a previous pic, going down through the engine bay and back up

http://www.voltzwagon.co.uk/dusty/lp...henginebay.JPG

and a view under and at the back of the rear wheel arch, the loops in the pipe arn't exactly tidy but necessary to prevent vibration loosening anything
http://www.voltzwagon.co.uk/dusty/lp...rwheelarch.JPG

so we've gon from the filler to the tank, from the tank to the LPG solenoid (via outside) then we are going backdown to the exhaust probe, from the exhaust probe back up into the engine bay to the vaporiser and thats the high pressure stuff done!

pop your mixers on top of your carbs and pop your filter ontop of the mixer (might be as simple as it sounds but unlikely) and take your rubber LPG hose from your vaporiser to the inline power valve then to a "Y" piece (if you have twin carbs) and then to the feeds on the mixer rings sitting ontop of your carbs (that you had no problem fitting )

heres a pic of the power valve
http://www.voltzwagon.co.uk/dusty/lpg/powervalve.JPG

Now, my kit said that most idle systems on carbs take thier air feed from after the petrol is mixed or something like that but on my twin solex, I have a pipe that usually goes from the carb to the filter housing. this means at idle, there would be no gas going into the engine because all the idle suck is going through this pipe which has no gas in it so would (and did ) result in running at high revs but idle just stalls, so the idle pipe from the one solex carb has to pe fitted to an inlet on the side of the new mixer rings so it has gas to idle. The scond lot of mixer rings I got from the supplier had this port with a blanking plug so was easy but the smaller ones (that didn't quite fit) didn't have this port so I don't know how you would get round that if the rings you have have no blanking plug.

So thats the gas side done I think and now to cut off the petrol...

We've secured the petrol solenoid already to the firewall havent we, so basically we need to cut the main fuel/petrol pipe that feeds the carb(s) and pop one either side of the solenoid, hopefully thre pipe will be long enough or you will have mounted the solenoid in a place where the fuel pipe doesn't bend too much whereas would restrict fuel or even collapse and block the fuel line.
http://www.voltzwagon.co.uk/dusty/lpg/petrolcutoff.JPG
cool, now for the electrical side

what's electrical, lets think... there is no less than three lpg cut off solenoids, 1 already fitted to the tank, 1 you have fitted in the engine bay, and 1 built in to my vaporiser and guess what! they all have to work together! so that means a wire from the switch we are fitting in the dash ......

http://www.voltzwagon.co.uk/dusty/lpg/guage.JPG

and have run through conduit on the underside of the bus...
http://www.voltzwagon.co.uk/dusty/lpg/cableroute.JPG

goes to the tank solenoid (through the venting pipe) and too the solenoid in the engine bay, and to the solenoid on the vaporiser. all these solenoids are then earthed to the bodywork with the rings and crimp spades provided. so 1 wire runs to all the solenoids (positive) and then wires run from each solenoid to bodywork (negative) so in theory when you turn the ignition all the valves will open together.

Next we need a wire from the control switch (through the conduit on the underside) to the petrol cut off solenoid (and the other wire from the solenoid to earth/neg/bodywork)
in theory, when we decide that we wanna run on petrol the switch control will (at the press of a switch,) turn off the gas and turn on the petrol

Next a wire from the control switch to the tank sender gauge (so you can tell how much fuel is in) don't forget to go up the vent pipe!

Next wire goes from the control switch (mine needed lengthening) to the negative side of the coil. this is a safety feature so if the engine stops then all the solenoids switch off too.

two more wires to do if I remember, in the cab, one positive off the ignition and negative to bodywork. bingo ready to commision, (though I may well have missed something but I'll add as i remember.

Heres how I commisioned it:

you want to see if the whole thing has any leaks BEFORE you fill it with gas, this way isn't fool proof but i found a pretty good way of checking.

Get your foot pump and stick something rubber to make a seal against the filler, I used self amalgamating electrical tape from from an electrical suppliers. press the pumps valve thingy with its new seal against the middle of the filler and get pumping you'll here the air going in. go on keep going, now it all depends on how you want to do this, I took a feed off one of the lpg solenoids back to the battery positive, seen as they are all wired together that meanse a positive feed to the positive connection on one of the solenoids will open them all, may I suggest you put a 5 amp inline fuse inline with this jump lead because if something aint wired right then that wire may decide to overheat,melt catchfire fry your good work. grab some leak detector spray (fairy liquid and water in a spray bottle) and spray all your joints looking for bubbles , you'll hear a hissing as the air comes out the vaporiser into the rubber LPG pipe and into the carbs but this in normal. it's everywhere else that you dont want to hear the hissing or bubbling! check tank connections with leak spray
http://www.voltzwagon.co.uk/dusty/lp...onnections.JPG

and the exhaust probe and everywhere you have put a fitting, at this point you will realise that you haven't put nearly enough pressure in the tank with your foot pump to check all these cause the hissing stopped 5 minutes ago so back to the pump , go on go for 150 pumps this time!

so you got no leaks and you are ready to test out your new switch

start the van , a little red petrol light will be on the switch, it should start as normal because you haven't done anything apart from cut the fuel pipe and put a solenoid in it, if it doesnt start then get someone to turn the ignition on and off and see if the petrol solenoid is clicking open and shut as they do it (if not then check your wiring)

so it's running on petrol (and costing you a fortune) press the control button and all the lights go off. This means petrol is cut off and gas, so how come it's still running? because you have to run the float bowls down because they are full of petrol still, this, at idle takes about three minutes at idle on mine but you are supposed to do this while moving so wouldn't take that long. give it a rev and as the engine starts to die, press the control button again, and the orange gas light lights up with a reading of how much gas is in the new tank. NOTHING! as the engine dies to a halt and you here all the lpg solenoids shut off because the engine isn't running. thats good!
Now this is a bit of a bitch cause you now have no gas or any petrol in your float bowls so it aint gonna start easy (but worth it to test the system) click the switch oncemore to get the red petrol light back on and turn it over till it starts, Hope you charged that battery!
When it's going it's time for the most nerve racking outing of your life and thats to the nearest LPG filling station Oh my god!

Last edited by RianScott; 26-09-2009 at 09:31 AM..
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Old 21-09-2009, 02:22 PM   #7
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Last edited by grzesiek; 25-10-2011 at 09:09 AM..
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Old 21-09-2009, 03:36 PM   #8
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Oh just before you go to the lpg station, VERY IMPORTANT!!! open all the solenoids with our little jump lead and let ALL the air out the tank otherwise you won't ever get a full fill and will cause running problems!!!! then remove the jumplead so they are all closed!

Try to look like you know what you are doing even when you havent got a clue! otherwise it un nerves the forecourt staff, read up on how the pumps operate because there are different ones and you really don't want to look too much of an idiot (though there are usually instructions on the pump)

fill it up ! I had the boot open, the engine bay, kept stopping and listening and squirting with the leak detector spray, (I don't think all the people around were too happy with my actions but they hadn't got to drive home in it!)

Fill it till it slows right down, it should read 20% less than your total tank size, mine read 57 litres on a 70 litre tank

Go home and repeat the running on petrol and then emptieng the float bowls and then switch to gas, you might have to do this a few ttimes to bleed the system and get all the air out the pipes but mine fired pretty well straight away, once its idleing, SWITCH IT OFF, GET THE LEAK DETECTOR SPRAY, SPRAY ALL JOINTS AGAIN WITH SOLENOIDS POWERED AND CHECK FOR BUBBLES, THE HIGH PRESSURE OF LPG SHOWED A SMALL LEAK ON THE EXHAUST PROB THAT NEEDED NIPPING UP A BIT TIGHTER THAT THE FOOT PUMP METHOD DID NOT SO CHECK IT ALL AGAIN!

Well thats a fitting end to todays posts, maybe I'll talk you through the tunning later if many are interested though I'm still mastering that! BUT DO TAKE IT TO BE CERTIFIED FOR THAT PIECE OF MIND, THE EXPERTS WILL CHECK IT ALL OVER AND SAY IT'S SAFE AS LONG AS YOU HAVE FOLLOWED THE REGS AND FOR 35 IT AINT WORTH NOT HAVING IT DONE! (and for insurance purposes!)
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Old 21-09-2009, 03:59 PM   #9
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good job on lpg fit .how did the probe work did the gas go all the way into the exhaust .have you got any pics of probe before fitting all the best daz
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Old 21-09-2009, 04:07 PM   #10
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Last edited by grzesiek; 25-10-2011 at 09:09 AM..
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