V8 LPG install

Jon Wildsmith

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I have just finished installing an LPG kit and thought I'd post about it. The kit I used came from Tinley Tech (http://www.tinleytech.co.uk) and is straight forward enough to fit but the information is spread across 4 documents so you need to keep swapping between them a bit. The sales blurb suggests 3 days I think for the install but that must be for an inside tank on a 4 cylinder engine! I bet I've spent 5 days on it although I haven't been keeping a count.

I went for the 110lt single hole cylinder tank. There is a 140lt tank that would also fit but it has a 5cm bigger diameter and for obvious reasons I didn't want the tank to hang down more than the 110lt. When choosing the tank I cut a 40cm circle of cardboard to hold under the back of the truck so I could get a better idea of space usage and this size combined with my 40mm body lift has good clearance and leaves plenty of room for a rear winch still:

Image0057.jpg


Getting the underslung tank in just the right spot, so it is as far forward as possible took quite a bit of work and then getting it strapped in place was a PITA that our sloping drive didn't help with. A smaller tank, torroidal or interior tank would probably take a lot less cursing to fit. When positioning the tank beware of the big plastic box that goes round the hole and make sure it won't interfere with anything when the tank is rotated to the correct angle. Also note that my exhaust has been re-routed at the back to be able to fit this tank. With a standard exhaust routing a shorter tank would be needed.

With the tank installed I started in the engine bay and did the gas injection nozzles. These are just little threaded brass fittings that you drill and tap the manifold to accept. I covered this part in another thread - viewtopic.php?f=13&t=7072 - where you see I chose to put the fittings into the back of the manifold, right opposite the petrol injectors, as close as can be to the intake valves and in a central position:

Image0086.jpg


That did mean using a full 300mm of hose to each nozzle (the max recomended in the instructions) but the alternative positions were less than ideal and I felt position was more important than hose length within reason. While the manifold is off for the gas nozzles, check if you need to add ports for the pressure sensor and also for the FlashLube feed if you're using that. On this engine there are already 2 suitable ports to tap into but it needs thinking about while the manifold is off.

Next up is finding suitable positions for the gas injector rails and mounting those. The choice is mainly made for you by the length of hose available:

Image0094.jpg


I put the ECU, vaporizer, shut off solenoid & pressure sensor where the AHC pump used to live:

Image0097.jpg


The mounting bracket I made for the ECU holds it away from the inner wing so there is somewhere to stuff surplus wire because the ECU loom is quite generous and mostly has connectors already fitted to the ends so shortening them isn't practical.

It's really then just a case of working through the install diagrams and instructions connecting all the pieces together. I plumbed the vapouriser hot water supply into the rear heater pipes:

Image0099.jpg


I opted for the pre-made injector looms and I'm glad I did. I think it was £30 extra but they just plug in rather than having to cut the OEM wiring and splice in the two ends to go to the ECU and back. Round the petrol injectors is quite a crouded space and although you might be able to fish that section of the loom out a bit it would still be a lot of work to save £30!

Once everything was connected I went to the local LPG place and put 15lt of gas in so I could do some testing. I did need to tighten a couple of connections when spraying them with soapy water revealed a slight leak and I was surprised just how tight the fittings had to be done up to seal them but I expect that's because of crushing the olive (you can power the shut off solenoids manually to let gas flow for leak testing).

Then I installed the software on my laptop and hooked it up to the Gas ECU. You have to configure the software to tell it what parts you're using and then you can run a self calibration mode that works out the basic mapping needed for you. You can then do lots of adjustments to tweak it for different RPM and loads but I've only done the initial calibration so far and I can't tell the difference between the petrol and LPG (except the LPG only cost 60p a litre :mrgreen:). I haven't run it on LPG much at all because I need it inspecting and certified before my insurance will be happy with it so I just have to wait till Tuesday's inspection now before I refine the settings.
 
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Crispin

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Nicely done Jon.

I assume the Flashlube is for the additives now removed from fuel?

How does the ECU look in terms of protection? Next time you go wading?


With the software, how does that control everything? Does it switch from gas to petrol at a certain load? Is there a gas gauge or does it switch over automatically when the gas is empty? What's your expected mileage on a 110L tank?

Questions Questions Questions :D
 

Jon Wildsmith

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Here's a more up to date picture showing the fully populated LPG corner. You can see the Flashlube ECU double sided sticky taped to the LPG ECU.

Image0103.jpg


I put the filler in the rear face of the back bumper because I've read / heard rear facing makes it easier to pull up either side of the LPG fill point.

Image0104.jpg


Another shot of the lpg tank from down low:

Image0105.jpg


and again from bumper level. Good clearance and you could live with it hanging down another 5cm I suspect but a tank of petrol and a tank of LPG is as much range as I want so the extra capacity isn't worth it for me.

Image0106.jpg


Here you see the LPG level gauge and change over switch on the right hand side below the FlashLube sticker. To the right of the sticker is the warning led for when you get low on Flashlube. The sticker has a hole in the middle and should be over the led but it doesn't fit very well so I'll have to fiddle with that later when I've nothing better to do :roll:

Image0108.jpg


Crispin said:
I assume the Flashlube is for the additives now removed from fuel?
Yes, LPG is apparently a very 'dry' fuel.

Crispin said:
How does the ECU look in terms of protection? Next time you go wading?
Should be AOK, all the connectors are the water proof type and sealed but only time will tell. Talking to a friend with a back street garage that has seen a lot of LPG converted LR products it doesn't sound like water should ever be an issue.

Crispin said:
With the software, how does that control everything? Does it switch from gas to petrol at a certain load? Is there a gas gauge or does it switch over automatically when the gas is empty?
You only have to hook it up to the PC to configure it, after that it takes care of itself. You *can* program it to switch to petrol at high loads but I don't know if that will be needed - the couple of full throttle standing starts I did earlier suggest there's no need but I will need to live with it for a while to really understand the extent of the power loss on LPG. The medium term plan is to get a dual map piggy back ECU fitted (Unichip) and get it set up properly on a rolling road for both fuels so there really shouldn't be any difference. Normally you leave the change over switch set to LPG and once the vapouriser is warm enough it will change over to gas and stay on it till you run out when it will beep and switch back to petrol.

Crispin said:
What's your expected mileage on a 110L tank?
I can only guess / speculate at the moment. LPG tanks are only filled to 80% of their gross capacity. The remaining space is to allow for expansion if it gets hot, but you can tweak the level sensor and squeeze a bit more in if for example you're going to start useing it right away i.e. an ongoing journey. As it's effectively an aux tank I can run it dry and not have to keep some back in reserve. Fuel consumption on LPG is higher per litre because it has less energy per litre. I'm guessing that all means about 300 miles per tank of LPG at a cost of £56 at current prices.

Depending on the expected availability of LPG, I can either have cheap motoring with a tank of petrol in reserve, or normal motoring with a tank of LPG in reserve :D

If in a few years I start wanting to go long range where there's no LPG I would remove the OEM petrol tank, fit the current LPG tank in its place, put a 180ltr long ranger petrol tank under the rear and run with 180lt petrol with a tank of LPG in reserve just for emergencies.
 

Andrew Prince

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Hi Jon,
Out of curiosity - how much do you reckon a full tank of LPG plus the tank itself weighs? I presume it doesn't add significantly to your overall load so not a concern.

Jon said:
If in a few years I start wanting to go long range where there's no LPG I would remove the OEM petrol tank, fit the current LPG tank in its place, put a 180ltr long ranger petrol tank under the rear and run with 180lt petrol with a tank of LPG in reserve just for emergencies.
If there's no LPG, wouldn't it be easier just to swap the long ranger for the LPG tank and leave the OEM where it is - that way you can use both tanks for petrol :mrgreen:

Cheers,
 
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Jon Wildsmith

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A full tank of LPG plus the tank itself is probably only around 75kg and as you can see it sits quite close to the axle. I've been running about with much more than that in the way of recovery gear, tools etc to keep the spring rate under control. Now the constant load is increased they can come out except for journeys they're needed on when I'll put a bit of air in the bags :D

I was tempted to just put another petrol tank under the back or make do with jerry cans but the price of LPG is attractive when you look at the longer term costs. Ask me in say 8 years time if I think it was worth the trouble ;)

Andrew Prince said:
If there's no LPG, wouldn't it be easier just to swap the long ranger for the LPG tank and leave the OEM where it is - that way you can use both tanks for petrol :mrgreen:
A lot of the miles would still be where LPG is available though, say as you go through Europe and back, so that's a roughly 40% smaller fuel bill for that segment of the journey so I can afford to go 40% further ;)
 

Rob

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Jon is this a difficult job? All the LPG installers i have rang assured me that fitting a LPG kit is difficult to get wrong but to tune it right you need "specialist" knowledge. Would someone with little mechanical experience but ambitious (and some theoretical technical knowledge) be able to install it? I am considering this for my 2.5l 10 valve volvo 850 which only manages 29mpg. Big engine not allot of power :( . The costs of getting this done at an installer ranges from £1400 to £1750 + VAT so not keen on that route.
 

Jon Wildsmith

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IMO it's not technicaly difficult Rob, just a bit time consuming and some of it might be a PITA depending on where you put the tank. For example I've forgotten to mention that the kit I used comes with 8mm copper pipe and it can be a right PITA to get it into the shape and place you need it! If I did it again I would trial fit the tank and then remove it again while I ran the pipes because it would be a lot easier without the tank in the way. I think I did read somewhere online that there is a flexible plastic pipe alternative you can use which is much easier to manipulate. On your 2.5l engine I think you'd only have a 6mm pipe from the tank to the engine bay anyway and only 8mm for the filler pipe.

Keep in mind I only have a single install experience to make these statements from. Setting it up - mine goes well on the self learnt settings and the adjustments you can make in the software are not rocket science - compare some numbers between running on gas vs running on petrol and adjust. Might take you longer than someone with more experience but as it's your car I wouldn't mind betting (a small amount only :lol: ) you will take the time to get it set up better than A.N. Other .

The older kits were probably much harder to set up and of course the pro installers have jobs to protect.

I'm luck that a) there is an LPG tank place about 1 mile from here and b) it's at a LPG fitters who will inspect and certify the install for me so I don't even have to go back to Tinley Tech for that.

The couple of things I phoned Tinley Tech to check up on they were very helpful.
 

Chris

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Well why not? Need isn't the prime driver here. No one NEEDED to go up Everest did they? You don't need a rear winch on your throbbing monster, but the fact that you can if you feel like it is just the spirit that we all need. I may fit side winches. Hah, now that's thinking outside the box. Or padded cell, whichever.

Chris
 

Chris

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What is the general availability of autogas nowadays? It's put me off buying an LPG conversion 80 to be fair. Not sure that I could get gas where I go. Hard enough getting derv! I am also nervous of buying one with a dodgy install.

C
 

Jon Wildsmith

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Battered and Blue said:
What is the general availability of autogas nowadays? It's put me off buying an LPG conversion 80 to be fair. Not sure that I could get gas where I go. Hard enough getting derv! I am also nervous of buying one with a dodgy install.
It seems like availability is quite good but I expect it will vary a lot from area to area. As well as the normal forecourts there are a lot of small suppliers that just have LPG, like the one near to me. Places like Countrywide stores you can get an account and a key to use their tanks and there are probably others, got to learn about all this still.

Time will tell what the real answer is and it will nearly always be a bit more trouble to get a tank of LPG vs derv but at the moment it's £0.60 vs £1.21 by us and it's actually easier for me to get LPG than petrol as there's less queing and it's closer.
 

Dark Dude

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Gordon Bennett Jon! You are a wealth of information. I've been driving LPG for almost four years and quite frankly I wish I'd switched sooner. Currently I run on a single point Emmergas LPG system which had been installed before I brought the vehicle (ie: my current mode of transportation, a MkII LWB Vauxhall Frontera 2.2 Petrol ). Apart from changing the vaporiser, my system has been easy to maintain and 100% reliable. There are though things to watch out for.

1. If you're going to do the install yourself and you later intend to sell on the car, make sure that the install has been properly checked and cleared by a trained LPG installer and the install issued with a LPG certificate. I wouldn't buy a LPG car without one. PERIOD!
2. The cars cooling system is the LPG's weakest link. At the every least you should invest in a new radiator just to be safe and sound. IMHO: All piping should be replaced with new as well as the water pump.
3. What you loose in mileage in the summer, you will gain back in mileage in the winter. Currently on a run, in the summer I can squeeze out 190 miles before I run out of LPG juice as opposed to 220 miles in the winter. It's the ONLY time I pray for cold winter nights and even colder winter days.

As for the Flashlube petrol additive you've included along with your LPG install, I've NEVER heard of it before and I've never used it. Personally I'm planning to go with a PRINNS multipoint system as soon as I get my 100 and get it fitted by a expert but thanks for the pointers anyway.

John

The Dark Dude.
 

Dark Dude

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Update:

An viable alternative to fitting a Flashlube system is to just run on petrol once in a while (during a run) in order to grease the wheels of industry. It's worked for me.

John

The Dark Dude.
 
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