SteveG Posted May 6, 2008 Share Posted May 6, 2008 So what's recommended for LPG system for a 4.6 Thor V8 engine? From my brief look it looks like a Multipoint Sequential Gas Injection System seems best, but as I know bugger all, can I have an expert opinion please. Also why do fitting costs vary so much? Surely a certified install can't be that different that some charge £550 more. Lastly, a couple of companies that are localish to me are Tinley Tech, http://www.tinleytech.co.uk/home.html and Wains, http://www.wains-classic-rebuilds.co.uk/ Anyone have experience of either? Cheers Steve Quote Link to comment Share on other sites More sharing options...
Scotian Posted May 7, 2008 Share Posted May 7, 2008 I only had a single point system on a 2,5 petrol Landrover engine but I recomend Tinleytech as he was my supplier and was very helpful with after sales service. He even answered his phone on a sunday afternoon and talked me through a problem I was having when fitting it. Quote Link to comment Share on other sites More sharing options...
nas90 Posted May 7, 2008 Share Posted May 7, 2008 So what's recommended for LPG system for a 4.6 Thor V8 engine? From my brief look it looks like a Multipoint Sequential Gas Injection System seems best, but as I know bugger all, can I have an expert opinion please. Also why do fitting costs vary so much? Surely a certified install can't be that different that some charge £550 more. Lastly, a couple of companies that are localish to me are Tinley Tech, http://www.tinleytech.co.uk/home.html and Wains, http://www.wains-classic-rebuilds.co.uk/ Anyone have experience of either? Cheers Steve On a twin carb set-up you can have 2xsingle point injection without too many problems With the petrol injected systems using a plenum chamber a single point injection would not run correctly and that is why they will have 8xinjection into the plenum just above each cylinder. My nas has been running with the 8xinjection for 6 years without any major problems. The gas system has it's own ecu to control changeover gas to petrol and injection of gas. Quote Link to comment Share on other sites More sharing options...
SteveG Posted May 8, 2008 Author Share Posted May 8, 2008 Thanks for the replies and info. Dave, what servicing does your system need? It seems that I can fit a 95l tank in the spare wheel well which leaves the boot space intact. I'm assuming that this will give me an effective range of around 300 miles on LPG between fills, does this sound about right? On the driving we do here the RR does about 19-20mpg, so I'm assuming that it will do about about 15-16mpg on LPG (~3.5 miles per litre). What are your thoughts? Cheers Steve Quote Link to comment Share on other sites More sharing options...
Scotian Posted May 8, 2008 Share Posted May 8, 2008 I had a 55 liter tank in the back of my 90 and with the 2.5 engine only giving between 12 and 14mpg I was filling up every 115 miles. It was a real main in the neck, especially since I couldnt run it on petrol for various reasons. It made getting to Kinloss in Scotland impossible at night (had to be in the day time to reach between lpg stations that were open) Quote Link to comment Share on other sites More sharing options...
nas90 Posted May 8, 2008 Share Posted May 8, 2008 Thanks for the replies and info.Dave, what servicing does your system need? It seems that I can fit a 95l tank in the spare wheel well which leaves the boot space intact. I'm assuming that this will give me an effective range of around 300 miles on LPG between fills, does this sound about right? On the driving we do here the RR does about 19-20mpg, so I'm assuming that it will do about about 15-16mpg on LPG (~3.5 miles per litre). What are your thoughts? Cheers Steve I have a 80 litre tank on the right tub wheel box. I can fill to 80% so that is 64 litres and that on a long run will take me 170 miles, short run or towing 150 miles. The petrol tank is 55 litres and on a long run will take me 160 miles, short run or towing about 140 maybe 150 miles. So the lower calorific value of the gas gives less miles per litre. Remember my nas is an auto and plenty of ironmongery on the front to make a mockery of any wind tunnel testing I had some issues when the system was first installed and the installer re-mapped the gas ecu whilst I was driving the nas from his laptop. Since then I am ashamed to say that the gas system has received nil servicing That is apart from about every 4 months or if running erratically I clean the (very small) in line filter which is dead easy to take apart sitting on the evaporator. At the same time the stepper motor valve at the back of the plenum gets cleaned. Sometimes at road junctions when running gas the engine will stop, when this happens frequently and there are lots of junctions I just switch to petrol and my system has a switch with the contents LED's simple to operate. I am sure that this running problem is mainly down to dirty fuel since it does not always happen! Quite a few people have mentioned fuel quality and I tend to fill-up at those outlets that seem to give less problems. Hope that helps. Dave Quote Link to comment Share on other sites More sharing options...
SteveG Posted May 9, 2008 Author Share Posted May 9, 2008 Hi Dave Thanks for the response. I wan't aware about the 80% fill, I assumed a 95l tank would hold near to 95l Also wasn't aware of differing quality of LPG, so I'll keep that in mind when trying out local garages. Thanks Steve Quote Link to comment Share on other sites More sharing options...
nas90 Posted May 9, 2008 Share Posted May 9, 2008 Hi DaveThanks for the response. I wan't aware about the 80% fill, I assumed a 95l tank would hold near to 95l Also wasn't aware of differing quality of LPG, so I'll keep that in mind when trying out local garages. Thanks Steve Steve, yes the 80% rule is across the board any make of tank. RR and Disco's may have 2 smaller tanks each side of the chassis but you lose off-road capability. The tank being inside the nas tub is still nice and clean, stick it underneath the vehicle and you have potential corrosion problems. Dave Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted May 9, 2008 Share Posted May 9, 2008 Steve, yes the 80% rule is across the board any make of tank. The tanks are sealed pressure vessels so need expansion space, or else things will get exciting on hot days... When my dad was working out in Baku the local bottled propane suppliers thought they were doing them a favour if they over filled the cylinders. On one occasion the end blew out of a large cylinder on one of the ships, punching the cylinder through the steel deck above and launching it into the sky... About 15mpg (I could manage 18 on a long cruising run) was what I got from the Range Rover on LPG. Make sure your ignition is in tip top condition or it'll run badly and give you lousy economy - LPG is harder to ignite than petrol so it's more sensitive to a weak spark. Quote Link to comment Share on other sites More sharing options...
Drakes Posted May 12, 2008 Share Posted May 12, 2008 I have run a 4.6HSE for 60000 miles on a multipoint system and you can not tell the difference when running. It has the 95 litre tank in the floor and I normally get 230-250 from it and the trip computer shows 18mpg so that what it thinks it is doing on petrol just to allow you to compare your normal fuel consumption with mine. My system is an AG and was fitted by a company called Gastech in Huntingdon, not the cheapest but really good workmanship and customer service. Servicing is just a filter change and check over everty 12000. Quote Link to comment Share on other sites More sharing options...
SteveG Posted May 12, 2008 Author Share Posted May 12, 2008 Thanks for the info everyone. Thanks for the comparable info Drakes, so it looks like yours is doing about 15-16mpg on LPG and 18mpg on petrol. So I should see about 16-17 on LPG given our driving around here. I saw Gastech, but they've moved from Huntingdon to somewhere in Essex. Also their fiitted price is £2300 compared to £1750 for Wains Classic Rebuilds. Wains seem to have a good reputation and they insist on changing out the leads and plugs for new> You hav eto pay for these, but they include free fitting of them in the price. It seems a no brainer to put LPG on as at current prices it will pay for itself within a year. Cheers Steve Quote Link to comment Share on other sites More sharing options...
gav- Posted May 12, 2008 Share Posted May 12, 2008 i have just brought a p38 95 4.6 with lpg, and its a great car, but i am only able to put in 40l of lpg in the 90l tank. i am not sure why as i havent investigated. but have obviously the pressure is effected by the temp of both the gas and the tank. v8david has the same issue. on 40l i achieved 160 of motorway driving - 18mpg. Its an OMVL system which was supplied by go.lpg.co.uk. I brought it fitted. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted May 12, 2008 Share Posted May 12, 2008 How do you know it is empty before re-filling? You're not relying on the guage are you? These are notoriously unreliable so just keep going till you run out, then try re-filling. If the problem persists then the 80% valve needs replacing, a job you ought to get a LPG fitter to do IMHO. Quote Link to comment Share on other sites More sharing options...
gav- Posted May 12, 2008 Share Posted May 12, 2008 yeah i have been relying on the guage, ill run to empty next time and then see. cheers for the advice Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted May 12, 2008 Share Posted May 12, 2008 yeah i have been relying on the guage, ill run to empty next time and then see. cheers for the advice As Bowie69 says, LPG fuel guages are so unreliable most people ignore them and use their trip counter to work out range. No idea why no one has felt it worthwhile developing a decent fuel gauge system for LPG tanks Quote Link to comment Share on other sites More sharing options...
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