I know his has been covered loosely in the past but seeing as unleaded fuel hit £1.00 a litre today (officially) it needs to be done, and I want to demystify the whole matter once and for all.
What I am interested in finding out is what is the best method of carrying out an LPG conversion to a 325i. I know there are different types of kits and different methods of doing it, but what works best and is most practical.
Finally, where can you go to get all this stuff brand new. I'm not really interested in spending the rest of my life searching for parts on ebay in hope of making a complete kit.
I'm going t do one of these soon and will take the opportunity to document it all for the zone.
Many thanks.
Oh No! Not that LPG question again..
Moderator: martauto
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Brianmoooore
- E30 Zone Team Member
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- Joined: Mon Jan 10, 2005 11:00 pm
There are two sorts of LPG system generally available today. One is a single point system, using a venturi to draw the gas in, either with or without a lambda controlled feedback system to fine tune the mixture, and the other system uses vapour injection, using a modified signal for the petrol injectors from the original ECU, to control a set of LPG injectors mounted near the petrol injectors.
The second system is much more expensive than the first, and was introduced for two main reasons: 1) To achieve tighter control of emissions and protect the cat by utilising all the feedback and correction systems built into the petrol ECU, and 2) Cars were being made with plastic inlet manifolds. The venturi LPG system fills the inlet manifold and plenum with an explosive mixture, just like old carbureted engines did, and very occasionally, under certain unusual conditions, a blowback will occur. This normally causes no damage with an alloy inlet manifold, but plastic manifolds have been known to be blown to pieces.
Since all E30 engines have alloy inlet manifolds and the ECUs have next to no feedback functions, the venturi system is quite suitable, especially when fitted with an electronic feedback system.
I have been running a 325 touring on LPG for over seven years and about 80,000 miles with no serious problems at all.
To fit an LPG system, you will need a tank with a valve assembly and a filler pint to mount on the outside of the car. Tanks can be either a cylinder type, which will fill half he boot of an E30, or a toroidal (doughnut) shape that will fit in the spare wheel well. A 630mm X 215mm 52litre tank fits perfectly into an E30 well, projecting about 10mm above floor level.
The filler connects to the tank by either an 8mm copper pipe or a flexible rubber hose, and can be fitted anywhere on the outside of the vehicle, as long as it's well clear of the exhaust. They have been cut into the bodywork, bumpers, valences, fitted behind numberplates and attached to towbars.
A 6mm copper pipe goes from the tank to a filter/solenoid valve in the engine bay, and then goes onto the reducer/vapouriser. This device reduces the pressure of the liquefied gas in the 6mm line and turns it into a vapour. This process require considerable quantities of heat, so the vapouriser is plumbed into the cooling system, usually by teeing off of the heater pipes.
The gas then goes along a larger bore rubber hose, through a stepper motor controlled valve, and into the inlet manifold via a venturi plate, which, with a flap type air meter, is normally fitted before the air meter.
A lambda sensor is fitted to the exhaust and a small ECU interprets the data from this and the throttle switch to fine tune the gas mixture via the stepper motor.
A blowback arrestor/pressure relief valve also needs to be fitted after the air flow meter to protect the flap in the meter against blowbacks.
The advantages of LPG are reduced engine wear because LPG does not need mixture enrichment when cold, and doesn't wash oil off the bores, increased oil life because of reduced contamination, reduced co2 emisions and greatly reduced other emissions, vastly increased range without refuelling if you use both fuels and, of course, half price running!
Disadvantages are: Loss of boot space or spare wheel, the weight penalty of the tank, a very slight (frankly unnoticeable) reduction in power, relative lack of refuelling stations, limited range on LPG unless you have a huge tank (MPG is only 80% of that on petrol, and tanks are only 80% filled) and a restricted choice of insurance companies.
The second system is much more expensive than the first, and was introduced for two main reasons: 1) To achieve tighter control of emissions and protect the cat by utilising all the feedback and correction systems built into the petrol ECU, and 2) Cars were being made with plastic inlet manifolds. The venturi LPG system fills the inlet manifold and plenum with an explosive mixture, just like old carbureted engines did, and very occasionally, under certain unusual conditions, a blowback will occur. This normally causes no damage with an alloy inlet manifold, but plastic manifolds have been known to be blown to pieces.
Since all E30 engines have alloy inlet manifolds and the ECUs have next to no feedback functions, the venturi system is quite suitable, especially when fitted with an electronic feedback system.
I have been running a 325 touring on LPG for over seven years and about 80,000 miles with no serious problems at all.
To fit an LPG system, you will need a tank with a valve assembly and a filler pint to mount on the outside of the car. Tanks can be either a cylinder type, which will fill half he boot of an E30, or a toroidal (doughnut) shape that will fit in the spare wheel well. A 630mm X 215mm 52litre tank fits perfectly into an E30 well, projecting about 10mm above floor level.
The filler connects to the tank by either an 8mm copper pipe or a flexible rubber hose, and can be fitted anywhere on the outside of the vehicle, as long as it's well clear of the exhaust. They have been cut into the bodywork, bumpers, valences, fitted behind numberplates and attached to towbars.
A 6mm copper pipe goes from the tank to a filter/solenoid valve in the engine bay, and then goes onto the reducer/vapouriser. This device reduces the pressure of the liquefied gas in the 6mm line and turns it into a vapour. This process require considerable quantities of heat, so the vapouriser is plumbed into the cooling system, usually by teeing off of the heater pipes.
The gas then goes along a larger bore rubber hose, through a stepper motor controlled valve, and into the inlet manifold via a venturi plate, which, with a flap type air meter, is normally fitted before the air meter.
A lambda sensor is fitted to the exhaust and a small ECU interprets the data from this and the throttle switch to fine tune the gas mixture via the stepper motor.
A blowback arrestor/pressure relief valve also needs to be fitted after the air flow meter to protect the flap in the meter against blowbacks.
The advantages of LPG are reduced engine wear because LPG does not need mixture enrichment when cold, and doesn't wash oil off the bores, increased oil life because of reduced contamination, reduced co2 emisions and greatly reduced other emissions, vastly increased range without refuelling if you use both fuels and, of course, half price running!
Disadvantages are: Loss of boot space or spare wheel, the weight penalty of the tank, a very slight (frankly unnoticeable) reduction in power, relative lack of refuelling stations, limited range on LPG unless you have a huge tank (MPG is only 80% of that on petrol, and tanks are only 80% filled) and a restricted choice of insurance companies.
Brian
I am having an LPG conversion on my GTB as we speak. I went through a company called greenfields, if memory serves me correct.
I am having an LPG conversion on my GTB as we speak. I went through a company called greenfields, if memory serves me correct.
Toby
1987 E30 M3 S14 Turbo
1971 V12 E type Roadster
1987 E30 M3 S14 Turbo
1971 V12 E type Roadster
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HairyScreech
- Engaged to the E30 Zone
- Posts: 6265
- Joined: Sun Jan 21, 2007 11:00 pm
as im now a student im considering picking up a gas conversion for mine, wish i had had the kit off the one that was scraped near me.
says a lot when a 21 yearold motorsport student starts to think petrol has become too expensive. tyvm mr.brown.
says a lot when a 21 yearold motorsport student starts to think petrol has become too expensive. tyvm mr.brown.
2.8 development thread http://www.e30zone.net/modules.php?name ... c&t=170822
m3.3.1 m20 thread - now running, chip needed - any volunteers?
http://www.e30zone.net/modules.php?name ... =viewtopic&
m3.3.1 m20 thread - now running, chip needed - any volunteers?
http://www.e30zone.net/modules.php?name ... =viewtopic&
Thanks Brian. I was hoping you would join in.
Stu, the simple fact is that most people would be afraid to do a DIY install themselves. In all honesty I think that DIY gas work of any kind is usually a bad idea, however if the job is simplified and explained then a lot more people would realise the pitfalls and benefits and know their limitations. All I aim to do is demystify the whole thing for myself and everyone else! Those who feel confident to do it themselves will then have a much better understanding of it.
LPG if treated badly will bite you, it is naturally very seeking and will leak wherever it can if not shown the correct respect. Jointing methods and pipe routing, as well as other factors need to be carefully considered. I am CORGI registered for LPG, but nothing to do with vehicle LPG unfortunately, although I have great knowledge of the LPGA who certify LPG installers of all kinds including vehicle installers.
So that leaves the question of parts. Where is the best place to buy from or are all installers importing their kits directly from Italy? There must be an importer or distibutor in this country that we can buy from direct.
Stu, the simple fact is that most people would be afraid to do a DIY install themselves. In all honesty I think that DIY gas work of any kind is usually a bad idea, however if the job is simplified and explained then a lot more people would realise the pitfalls and benefits and know their limitations. All I aim to do is demystify the whole thing for myself and everyone else! Those who feel confident to do it themselves will then have a much better understanding of it.
LPG if treated badly will bite you, it is naturally very seeking and will leak wherever it can if not shown the correct respect. Jointing methods and pipe routing, as well as other factors need to be carefully considered. I am CORGI registered for LPG, but nothing to do with vehicle LPG unfortunately, although I have great knowledge of the LPGA who certify LPG installers of all kinds including vehicle installers.
So that leaves the question of parts. Where is the best place to buy from or are all installers importing their kits directly from Italy? There must be an importer or distibutor in this country that we can buy from direct.
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StuBeeDoo
- Engaged to the E30 Zone
- Posts: 6756
- Joined: Sat Feb 05, 2005 11:00 pm
- Location: Up My Own Arse
I got mine from http://www.gordonfinlay-lpgconversions.co.uk/ Gordon was very helpful, patient and supportive.old_skool_2002 wrote:So that leaves the question of parts. Where is the best place to buy from ? There must be an importer or distibutor in this country that we can buy from direct.
This is why I no longer drive an E30......
StuBeeDoo wrote:I got mine from http://www.gordonfinlay-lpgconversions.co.uk/ Gordon was very helpful, patient and supportive.old_skool_2002 wrote:So that leaves the question of parts. Where is the best place to buy from ? There must be an importer or distibutor in this country that we can buy from direct.
Nice one, there's a place for me to start then - Cheers Disco Stu
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klu99apm
- E30 Zone Newbie
- Posts: 134
- Joined: Sat Mar 05, 2005 11:00 pm
- Location: Rutland / Derbyshire
I bought my kit from this firm a couple of years (and 30,000 miles) ago. They seem to have outcourced the LPG side to another firm recently (I think another family member) whose website is currently down but it was working earlier in the week so I assume its a temporary glitch.
Navitron
Otherwise other people I know have used this firm:
Tinley Tech
HTH - Andrew
Navitron
Otherwise other people I know have used this firm:
Tinley Tech
HTH - Andrew
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Brianmoooore
- E30 Zone Team Member
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- Joined: Mon Jan 10, 2005 11:00 pm
Only other place I know of that deals with DIY, is WTV-UK ( www.lpg-kits.com )
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Brianmoooore
- E30 Zone Team Member
- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
Ideally you'd want to use a vapour injection kit for these, especially the S50, but there is someone who produced a special combined mixer and blow back arrestor to enable a venturi system to be used with the M50.tbmw wrote:how hard/easy would this be to get to work on an s/m50?
am considering this swap in the future and wouldnt mind trying ot run on lpg
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Brianmoooore
- E30 Zone Team Member
- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
Fitting an LPG set up to a car generally isn't at all difficult, and can be done it a few easy stages without having the car off the road for more than a few hours at a time.
LPG is a much more suitable fuel for internal combustion engines than petrol.
LPG is a much more suitable fuel for internal combustion engines than petrol.