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LPG install


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Just recently I got myself a very nice 3.5V8 RR with LPG conversion. (it also got Megasquirt and EDIS )

I have been getting on with few little jobs that needed doing - brakes, dropping windows..... still more to come but they will get done when I got more time and money

One thing that I find needs my attantion asap is the mileage I get out of her - on the combined consumption of petrol and gas I can only manage approx 154 miles from full to empty. As we travel a lot this is not practical at all :(

The LPG kit is a Landi Renzo venturi type, closed loop. It has twin tanks under the back where the petrol tank would normally be, and a four gallon wing tank for petrol. I think there night be a problem with the petrol tank as the max we can fill it up is 10 liters. The twin tanks are very small ( 30l? each) with a maximum fill of about 46ltrs from empty

I can put in 80l's worth of undersill tanks (I would prefer those as i would not loose space in the boot) or go completley mad and have a boot tank as well as the undersill ones. The original LPG kit was instaled "up north" - do you know of anybody reliable and not costing the earth in the South ? Also they will have to be aproved installers as I think it may affect my insurance.

What are you experiances with different types of LPG install? What would you recomend?

How does everyone else get on when Euro travelling in terms of adaptors/availability etc?

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As far as installations go, you can buy the bits that you need, such as tanks and pipework, and have your resident man about the lab fit them for you. The qualified installer will be required to check and approve the installation before the first fill. Often the boys who work on and service fork trucks can be helpful with regard to this. I do know a man who can help if you get stuck.

If you fit underslung tanks, be sure to fit a large bore interconnecting pipe between the tanks, or you will waste most of your life trying to fill both tanks. This is also true of the pipe from the filling adaptor to the tanks.

As far as european travel goes, I would recommend fitting a removable adaptor. This will allow you to purchase the correct adaptor for the country you are travelling to. IIRC Belgium and Holland are different to the UK and France - someone on here will know for sure at this time of year.

As I am unfamiliar with your Megasquirtsky thingy, I cannot comment on optimum setup parameters. We run 22 degrees retarded on our 3.9 EFI with Mallory coil and dizzy, plus an RPI box of tricks to advance the timing 8 degrees on petrol, and thus give a seamless transition between both fuels as you switch over.

Adrian. :)

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I know nuffink about LPG, but the problem with the petrol tank may be a blocked breather which may have caused the tank to crush as fuel is pumped out and air couldn't get in. Wip the outer wing off and have a look see, itr's only a few screws to remove.

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I know nuffink about LPG, but the problem with the petrol tank may be a blocked breather which may have caused the tank to crush as fuel is pumped out and air couldn't get in. Wip the outer wing off and have a look see, itr's only a few screws to remove.


going to investigate that one next week :)

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I have two 40 litre tanks where the petrol tank used to be and (I think) a 36 litre tank in the rear wing, so you might just be able to get bigger tanks for the same location.

I used to get up to 200 miles on gas and I guess you could hope for 100 on petrol, out of a 4.2 LSE, (that was a closed loop multipoint kit).


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It's only four bolts plus the pipes to drop the petrol tank completely (which would also let you investigate and possibly fix the knackered fuel sender).

The LPG tanks are 35l each, which gives you an actual LPG capacity (with expansion space) of 56l. If you aren't getting this much in from empty then try a different LPG station - some seem to run below standard pressure and deliver less fuel. You should be able to get at least 170 miles range on LPG. Have you let Fridge loose tuning up the Megasquirt yet? Sorting out the ignition tables will make a big difference.

As said, provided you read the regs and follow them you can modify the LPG system yourself then get it certified afterwards. I was told some time back by a garage that it cost them £25 for an LPG cert inspection, as they didn't issue their own. I presume this was sans VAT and possibly trade price.

If you fit sill tanks you will need to either relocate the air suspension tank and pump/valve block (which is what I was planning to do) or rip the air suspension out completely and fit coils (which might be saner if you need bomb proof reliability miles from the nearest diagnostic computer). A cylinder in the boot will lose you a lot of load space, and you might as well have bought a truck with a full size petrol tank. The only other alternative is an upright toroid in place of the spare wheel, although I wonder how much this will affect handling having that much weight high up.

Rogue Trooper may still have a pair of suitable sill tanks from the range rover he broke.

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