Ideal 'classic' car contender for singlepoint conversion ideas?

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Budgetbond
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Ideal 'classic' car contender for singlepoint conversion ideas?

#1 Post by Budgetbond » Sun Aug 23, 2020 5:03 pm

As the subject title suggests, just a general point for discussion, I realise there may be some advantages to fitting singlepoint systems on older cars.

Anybody got any good suggestions or ideas of what older/classic cars would make an ideal contender for a singlepoint conversion?

What would make people's ideal preference?
(And why?)
Feel free to offload your bucket lists!!

Gilbertd
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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#2 Post by Gilbertd » Sun Aug 23, 2020 7:17 pm

Any older BMW, Mercedes, Volvo, Saab, Range Rover, etc, basically anything with a metal inlet manifold and hard valve seats. Preferably something with fuel injection (but not mechanical) and, ideally, electronic ignition rather than a distributor.
96 Saab 900XS, AEB Leo, sold
93 Range Rover 4.2LSE, Lovato LovEco, sold
97 Range Rover 4.0SE, multipoint, sold
98 Ex-Police Range Rover 4.0, AEB Leo, daily motor
96 Range Rover 4.6HSE Ascot, AEB Leo, my spare


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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#3 Post by LPGC » Sun Aug 23, 2020 10:18 pm

An unusual angle of approach...

I see Gilbert's points but would say regards the list of makes/engine/fuel delivery types general advice would be to fit a sequential system over a mixer system where possible. The main advantage of a mixer system is that it allows engines that have anything other than electronic fuel injection to be converted. The 'standalone fuel system adding extra reliability' aspect is usually considered an also ran (any advantages usually more than outweighed by the advantages of a sequential system) compared to a mixer system's main advantage.

It depends on what you call a 'Classic', to some this could be a 20 year old car, to some it means a lot older, old enough not to have to pay road tax and then maybe older still. Old cars are more likely to run a carb than any form of fuel injection except for a few early adopters (usually top end cars and then usually more likely Bosch K Jetronic mechanical injection before electronic injection). If you go back to old enough cars a mixer system would be the obvious choice.
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Budgetbond
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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#4 Post by Budgetbond » Mon Aug 24, 2020 4:57 am

Thanks all good points, I'm thinking hypothetically out of the box really for good older collectable candidates.

I remember having a mk1 6 series and was considering at the time whether to get it converted, I think that had a mechanical motronic system, I also remember the electrics on it were a mare it frequently wouldnt turn over to start and the common 'fix' was to go under the bonnet and bridge two 'pins' on like an early obd socket with a paperclip and it would instantly fire up then return back to the drivers seat, apart from that bit of embarrassment it was a great car that I luv'd.

I suppose Im thinking what 'classic' cars would an lpg conversion really be an asset and add value, usability or desirability too.

I can see that on Range Rovers it could be almost a 'must-have' perhaps.

I suppose it boils down to advantages of an lpg car and pro's and con's of a sequential and mixer systems, and which would suit.

Am I right in thinking that with mixer systems you can start on lpg from cold and it wouldnt matter whether the petrol system was working or even whether you could dispense with the petrol tank if required,I could see on older cars, maybe ones that consume quite a bit of petrol, or do quite a few miles, it would be really handy if a vehicle had emissions issues or had fuel injectors or carburettors that were notoriously 'unreliable', I remember my dad having a Triumph 2.5 PI that was forever breaking down!!

Are mixer systems as harsh on some of the electrical components?

And I know its probably quite obvious but why not mechanical fuel injection and the requirement for electronic ignition?

Anyway its just a general discussion if anyone cares to chip in.

So am thinking that if you could find a really desirable classic, iconic looking car with a larger engine and maybe luxurious too, with a v rusty hard to replace petrol tank and a good space for an lpg one instead, with a notoriously unreliable petrol injection or carb system you could disregard that struggles on emissions at mot time anyway, and an already rusted petrol filler pipe to boot, would make a really great ideal candidate for a conversion!!

So, am thinking, what other things or cars would make peoples ideal 'bucket-list' conversions?

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#5 Post by Gilbertd » Mon Aug 24, 2020 10:13 am

By converting a 'Classic' car you are going to remove value rather than add it as people tend to want their Classics to be original. Admittedly, you'll make something with a larger engine cheap to run, but won't add value. For some cars there are small petrol tanks available so you remove the original large petrol tank, fit an LPG tank and a small, 4-5 gallon, petrol tank so you have a reserve for the day you run out of LPG.

My reasoning for sticking with a mixer system is that it is a stand alone fuel system. So if the petrol system packed up for whatever reason I can still run on LPG and vice versa. Yes, they will start and run on LPG from cold, mine switches over on falling revs at 1,100 rpm, so I start the car, blip the throttle and it changes over as the revs drop and runs on petrol for no more that a second or so. Ordinarily the only part of the petrol system that is used by a mixer system is the TPS and lambda sensor. I run a separate lambda sensor purely to drive the LPG system (so have two, the petrol one and an LPG one in the RH downpipe). Not sure what you mean by systems being harsh on the electrical components. LPG needs a better spark than petrol so if the plugs are worn it will put more strain on the coils but you shouldn't be running around on worn out plugs anyway.

Mechanical injections adds it's own problems as there is this great big plate sitting in the intake airflow that is moved by the incoming air and adjusts the fuel metering. You need to work out a way of holding it open when running on LPG. Carbs present their own problems unless you start on LPG and never let the float bowl fill otherwise you will be dual fuelling, at least until the float bowl is empty. Requirement for electronic ignition is my own preference, distributors are an invitation for a misfire, the one thing you do not want on a singlepoint. Particularly these days where replacement parts are almost certainly pattern parts. A good example being the rotor arms on the Classic Range Rover, if you've got an old one no matter how worn it will still work more reliably than a brand new pattern one. It may not work better but it will still work whereas the new ones have a habit of the insulation breaking down and failing with no warning at all.

Older Jags convert well too but if you find a car with a rusted out fuel tank, chances are the rest of the car will be in the same state. But if it's iconic and luxurious you are after, Jag XJ6 or Rolls Royce Silver Shadow would be on the list too.
96 Saab 900XS, AEB Leo, sold
93 Range Rover 4.2LSE, Lovato LovEco, sold
97 Range Rover 4.0SE, multipoint, sold
98 Ex-Police Range Rover 4.0, AEB Leo, daily motor
96 Range Rover 4.6HSE Ascot, AEB Leo, my spare


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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#6 Post by Budgetbond » Mon Aug 24, 2020 12:49 pm

Cheers Richard some v interesting and illuminating points there.

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#7 Post by Budgetbond » Mon Aug 24, 2020 12:52 pm

Im just trying to expand the repertoire + scope of lpg systems thats all.

Here's a couple of slightly lateral suggestions, feel free to add!!

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#8 Post by Budgetbond » Mon Aug 24, 2020 1:02 pm

http://www.yorkshirebears.co.uk/wp-cont ... Large.jpgt

With great location for an lpg tank!!

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#9 Post by Budgetbond » Mon Aug 24, 2020 1:10 pm

https://drivetribe.com/p/my-restored-19 ... Irx6L-4A2g

An lpg tank would also have necessitated the need for the police to place a flag in the boot to improve handling!!

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#10 Post by Budgetbond » Mon Aug 24, 2020 1:38 pm

https://www.thesun.co.uk/motors/3815578 ... n-project/

I've just started fishing again since I was a kid and nowadays people use remote control boats etc, I'd just luv to roll up in one of these, dyou think an lpg tank instead of a lifebuoy would reduce the risk of getting stranded through a rusty petrol tank and also add some needed beneficial buoyancy or ballast!!
Last edited by Budgetbond on Mon Aug 24, 2020 2:22 pm, edited 2 times in total.

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#11 Post by Budgetbond » Mon Aug 24, 2020 1:50 pm

https://www.landroverexpedition.com/pla ... xpedition/

And obviously the venerable land rover, can placement of the lpg tank in place of the spare wheel on the bonnet or roof have other additional benefits or even be allowed or have drawbacks!!

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#12 Post by Budgetbond » Mon Aug 24, 2020 1:56 pm

Anyway, sorry Im going on with myself, I know with my own car, as long as it lasts, is one of those cars that people say "its got to be lowered" mainly for cosmetics, but its never really bothered me to do it, but with the addition of my lpg tank its now just given me the perfect ride height now ironically!!

Feel free for anyone to chip in with their alternatives!!

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#13 Post by Pinger » Sun Aug 30, 2020 1:53 pm

Budgetbond wrote:
Mon Aug 24, 2020 4:57 am

Am I right in thinking that with mixer systems you can start on lpg from cold and it wouldnt matter whether the petrol system was working or even whether you could dispense with the petrol tank if required,I could see on older cars, maybe ones that consume quite a bit of petrol, or do quite a few miles, it would be really handy if a vehicle had emissions issues or had fuel injectors or carburettors that were notoriously 'unreliable', I remember my dad having a Triumph 2.5 PI that was forever breaking down!!
I'm to some extent where you are looking in that I'm running a 21 year old V8 truck on LPG with a single point system. It came from the factory with electronic (but with a distributor) ignition and electronic fuel injection. Thus, it has a reliable and punchy ignition system (with sophisticated knock control) and all the necessary sensors for a closed loop single point mixer system (eg, TPS, O2 sensor, CPS) which on a vehicle much earlier than this may not be present. Given the debate here is between closed loop single point mixer and sequential injection systems - this is the bare minimum necessary to go beyond open loop systems. Retro fitting that lot will be an onerous task.

Re the 'classic' element - the 1990s is a good era to choose from. Sophisticated enough as outlined above but pre-dating emissions kit laden cars which introduced reliability issues. Pick something you'd enjoy driving before it becomes collectable and if it does rise to sought after status, you can always convert it back to original as LPG kit is all bolt-on bolt-off for the main part.

To your question above - yes they will start on LPG but with considerable cranking and inlet backfire risk. Much better to start on petrol and as GilbertD outlined, change immediately to LPG. When my petrol pump was playing up I sorely missed that capability.

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#14 Post by Brian_H » Sun Aug 30, 2020 6:14 pm

If you want to see something that only runs on gas, this thread is worth a read, though make sure you have a spare hour when you go for it.
viewtopic.php?f=33&t=13792

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#15 Post by Budgetbond » Sun Aug 30, 2020 8:40 pm

Jeez Bri cheers am gonna embark on that hour-long epic!! And thanks for your points pinjer, I was just trying to think of ways to get a win-win Lpg conversion-wise, ie. Find a desirable but thirsty classic to run cheaper on Lpg also with inherent common or age related problems you could almost disregard or dispense with at the sametime by fitting the lpg kit in the process.
And yeah it's a bit of a shame in this country that converted cars don't attract as much of a premium or demand as it should, maybe hopefully it could change.
I've got my eye on a converted car on eBay at mo but they don't seem to be too numerous at mo.

I suppose you could maybe get some value out of importing/exporting but then there's the rhd/lhd issue.

I do actually mainly town/urban driving so switching to lpg asap would be a bonus, I've got my coolant/engine heating up pretty much as quick as poss, but what sort of minimum switchover values do people use all year round on sequential is 25C and 1 1/2 minutes too soon?

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#16 Post by Gilbertd » Sun Aug 30, 2020 10:50 pm

Sounds a bit low to me, at 25C the engine will still be running a cold start strategy so the mixture will still be too rich. That's why coolant plumbing is important to get the reducer up to temperature as quickly as possible. The only real age related problems you get are on cars fitted with carbs when they start to wear, injection systems just work, so finding something that you can improve by fitting LPG is going to be difficult.

Imports from Japan and South Africa is where you want to be looking as they drive on the correct side of the road. Either that or import American Classics......
96 Saab 900XS, AEB Leo, sold
93 Range Rover 4.2LSE, Lovato LovEco, sold
97 Range Rover 4.0SE, multipoint, sold
98 Ex-Police Range Rover 4.0, AEB Leo, daily motor
96 Range Rover 4.6HSE Ascot, AEB Leo, my spare


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Mouse
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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#17 Post by Mouse » Mon Aug 31, 2020 12:25 am

Well, darned if I'm not stuck right in the middle of all this.

I have a thread here that I started about 10 months ago on a classic BMW. Big 3.5 l straight 6 engine, with electronic ingition that is ecu controlled.

Tbh, I've dragged my heels on the conversion, but not always by my design. Anyway, a closed loop mixer system is the advice I got here for my classic.

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#18 Post by Gilbertd » Mon Aug 31, 2020 9:52 am

I suggested them in my first reply, earlier BMWs convert very nicely. He's looking at it from the opposite way to how most look at it. Most have a car and want to know what system is best suited to it whereas he wants to install a singlepoint and is looking for the ideal car to install it on.
96 Saab 900XS, AEB Leo, sold
93 Range Rover 4.2LSE, Lovato LovEco, sold
97 Range Rover 4.0SE, multipoint, sold
98 Ex-Police Range Rover 4.0, AEB Leo, daily motor
96 Range Rover 4.6HSE Ascot, AEB Leo, my spare


Proud member of the YCHJCYA2PDTHFH club.

Mouse
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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#19 Post by Mouse » Mon Aug 31, 2020 4:10 pm

Ahh, I misread it as any classic car and missed the single point part.

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Re: Ideal 'classic' car contender for singlepoint conversion ideas?

#20 Post by Budgetbond » Tue Sep 01, 2020 12:39 am

Well I was just jumping the gun a bit in thinking what 'classic' cars would an lpg conversion give a new lease of life too or really increase modern day usability in, whether high mileage usage or not. (Was thinking older stuff initially)
It's a bit hypothetical really cos I've not quite got my first sequential kit working yet!!

But you never know there might come a day when any petrol IC engine just has to be able to run Lpg if you want to actually drive it much as opposed to just show and shine it.I

Yeah a nice older Bmw sounds like one of the best options what Beemer have you got Mouse I used to have the 635Csi and considered getting it converted before I unfortunately had to sell due to practicalities.

A Saab sounds quite interesting.

A Merc 190 would probably make a good long term bet but I bet even the price of those have increased quite a lot.

Dyou remember single point fuel injection, I recall as a kid my uncle getting a new Fiat Regata that had single point F.I dohc 100bhp and did 0-60 in less than 10 seconds and thought at the time wow!!
I assume with single point fi and carb engines you get no real efficiency losses having a mixer system.

I'm curious to what I've read/seen about timing advance processors are these for use on sequential kits or otherwise?

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