Duel Fuel Conversion.

[Guest BrainFluid]

Hey all

 

The only way I will be able to keep my new 1.6 as my main car I'm going to have to convert it to lpg.

 

Other than that I intend to keep the car completely standard...

 

Now this

is the best sample schematic that I could find for a 'sequential lpg' system. Its the most up to date lpg kit offering better preformance and economy.

 

I'm researching as to wether the 1.6 can handle one of these kits, ie, has everything that one needs.

 

I'm new to working on Petrols I'm more a Diesel man so exscuse my ignorance here...

 

Does the 1.6 have a lambda?

 

Any other comments/questions/advice is welcome.

 

Nate.

[littlemike 0]

I work at a Lpg conversion company and the best system that we fit is a Prinz system.

It can be connected to a Lambda for diag purposes, but generally isn't as all the gas ecu needs to be connected to to work out the correct fueling is the petrol injectors.

 

One thing that I will say is that Peugeot exhaust valves will fairly quickly work their way into the valve seats when running on Lpg and you will have to adjust the clearances to compensate, that is until you can't get a thinner shim...... I'm talking a lot of miles here, but it's worth thinking about.

 

Just looked at your diagram and that's a Prinz isn't it?!

[Guest BrainFluid]

Hello little mike! Your just the kind of fellow I hoped would bump into this post

 

I have no idea if its from a prinz system or not! Its just the best schematic I could find on a sequential system to check against.

 

With regards to the valve seats I had figured that They would all have to be hardend to run on lpg anyway?

Is it the case that a lot of folk dont bother? I think I would like to have a head prepared properly for the system in anycase.

 

Will I be able to run a sequential lpg kit in your opinion? I have heard that theese are the best as it allows you to tune the engine/lpg kit together so you retain all but just not quite the same level pf preformance as petrol, as opposed to up to 30% less preformance with the earlier kits.

 

Could you point me in the direction of any good reading material on the subject?

[jim21070 2]

Hi Nate,

 

I don't want to put a dampener on your LPG plans but why do you want to convert when a 1.6 can be a very economical little motor when well set up? It will return 40mpg on a run even being driven quite enthusiastically.

 

I would guess that the cost of an LPG conversion, which I understand must be done by an approved outfit for insurance purposes, would buy an awful lot of petrol and take you a very, very long way.

 

Unless of course you live next door to a Calor Gas Depot and have a sneaky pipeline

 

Or if the LPG conversion kit is very cheap or free.

 

Then it would make perfect sense

[littlemike 0]

You won't lose 30% of your power with an earlier type of kit. Some cars you will notice a small drop in performance, but with most cars you can't.

 

If it was me I'd use a 'normal' single point conversion. the 205 engine is simple so all you need is a simple conversion -you'll save more money that way. The mixer has to bolt onto the inlet of the airmass meter so that the flap doesn't upset the gas flow. The diameter of these mixers is around the same as the inlet to the meter so the engine won't get strangled as it were -which is where a lot of power loss can come from.

 

You could use a Prinz (or similar) system if you wish, it should run very well on a 1.6 ,but the front end kits alone cost £700 iirc and that's not fitted! A simple single point system should cost around £300 plus fitting for the lot.

 

Multipoint systems are expensive to fix when they go wrong too. The Prinz kits we've fitted so far have been fine, but some of the cheaper multipoint kits like Romano, Bigas and AEG seem to get through gas injestors fairly regularly ( they wear out!) and they're not cheap to replace. Sequential/multipoint gas kits tend to get obsolete fairly quickly too and some of them are impossible to get spares for.

 

I've not got any places that I can point you to to read up about Lpg, all I know is from doing conversions over the last seven years although I don't do many myself now (Yey!!). I quite often have to try and get the buggers running better though

Edited September 11, 2006 by littlemike

[Guest BrainFluid]

Hi Nate,

 

I don't want to put a dampener on your LPG plans but why do you want to convert when a 1.6 can be a very economical little motor when well set up? It will return 40mpg on a run even being driven quite enthusiastically.

 

Hey Jim. Okay, to cut a long sorty as short as I can I cannot see where I would get the extra fuel money from if I swop from my 205TD to the Gti1.6. The extra money would have to come out of what I save every month. So, If I save now and spend some money on a LPG conversion. I will still be able to save, and my out goings will be less...

 

Then there is the enviroment to think about. (after the money, cor its a sick world no?)

 

 

Phew. ( I am unsure as of yet if I'll be having the system put on the books or not, but I reckon what with it being gas I'll probably get it fitted proper like.)

 

You won't lose 30% of your power with an earlier type of kit. Some cars you will notice a small drop in performance, but with most cars you can't.

 

If it was me I'd use a 'normal' single point conversion.

You could use a Prinz (or similar) system if you wish, it should run very well on a 1.6 ,but the front end kits alone cost £700 iirc and that's not fitted! A simple single point system should cost around £300 plus fitting for the lot.

 

So how much would typical fittings cost for a Multi point kit and a single point kit?

 

So far your edging me over to the single point kit...Can you map the car to run at its best on LPG with single point? Should one be worried about backfiring with a Single point kit?

 

Would the Proper thing to do get the Valve seats hardened?

 

Thanks for the help so far Mike

[petert 587]

Would the Proper thing to do get the Valve seats hardened?

 

They are already hardened. That's why you can use unleaded fuel in them. You may wish to put harder ones in however. The key to LPG reliability is metallurgy - chrome stem valves (or tuffrided stainless) and bronze guides. Most vehicles have this combination now anyhow.

 

The key to maximising performance is a high CR and ignition timing. LPG requires lots of low down advance, but LESS total advance.

 

It's more important to get these points correct than worry about the mixer/converter type.

[Guest BrainFluid]

They are already hardened. That's why you can use unleaded fuel in them. You may wish to put harder ones in however. The key to LPG reliability is metallurgy - chrome stem valves (or tuffrided stainless) and bronze guides. Most vehicles have this combination now anyhow.

 

&

 

It's more important to get these points correct than worry about the mixer/converter type.

 

Going by what Mike said the seats will still suffer over time so I dont see the harm in doing so...Are the stem valves and the guides chrome and bronze on a 1.6 already?

 

&

 

This is my confusion. I had it figured that this was easyier to do with a multipoint, if that is not the case and I get some good advice that single point will do just fine I'm likely to go down that route. But I could just about get my wallet around using Multi point if that would be the very best route to go down too.

[jim21070 2]

Hey Jim. Okay, to cut a long sorty as short as I can I cannot see where I would get the extra fuel money from if I swop from my 205TD to the Gti1.6. The extra money would have to come out of what I save every month. So, If I save now and spend some money on a LPG conversion. I will still be able to save, and my out goings will be less...

 

Yes, that makes perfect sense I'm never far-sighted enough to see these things for myself

 

The more I think about it the more appeal it has. It will certianly be an unusual 1.6 and I for one will be following progress on this with interest.

[Anton green 12 1 Cars]

Nice thread Brainfluid. Ill be following this thread too as Ive often thought about converting my Mi205. I bought a CD-Rom from ebay which gives a lot of info on what is involved in the conversion. It was only a couple of quid and useful. Have a look around for info, you might not have to pay for any fitting charges if you are competent with the spanners..

 

Along the lines of this thread, how can I check on the materials in the head of my Mi engine to see if they are suited or not?

[petert 587]

The valves I have here are definitely not chromed, but that's not to say other batches aren't. Yes, they have bronze guides. Mi16's have very hard seats. i doubt you'd have a problem with them.

[rich_w 0]

Has anyone come across LPG injectors that go in place of normal petrol injectors? I've seen them mentioned but never found much more than that.

 

I was thinking of a full time LPG conversion.

[Guest BrainFluid]

Ill be following this thread too as Ive often thought about converting my Mi205. I bought a CD-Rom from ebay which gives a lot of info on what is involved in the conversion. It was only a couple of quid and useful. Have a look around for info, you might not have to pay for any fitting charges if you are competent with the spanners..

 

Along the lines of this thread, how can I check on the materials in the head of my Mi engine to see if they are suited or not?

 

Any chance of a copy of that cd if it's not copyrighted? there are places witch will certifiyyour own work if it passes thier tests for around £90. And it looks like pretert has the answer...

 

The valves I have here are definitely not chromed, but that's not to say other batches aren't. Yes, they have bronze guides. Mi16's have very hard seats. i doubt you'd have a problem with them.

 

Mind you, if the valves are replaced you might as well do the guides too no?

 

 

Has anyone come across LPG injectors that go in place of normal petrol injectors? I've seen them mentioned but never found much more than that.

 

I was thinking of a full time LPG conversion.

 

I 'think' that the multi point kits come with seperate injectors for the gas that are in addition too your petrol ones. For an always 'burning gas' kit I dont know.

 

I'm pretty keen on going for a single point kit now. We might as well find out it that works okay on a 1.6 first seen as its the cheapest method!

 

If I had a Mi16 though I would go for the multipoint though. I have a feeling that It would be worth it just because of the extra electronic tinkering capabilities.

Edited September 14, 2006 by BrainFluid

[feb 47]

Very interesting post Brainfluid. I was just reading in www.greenfuel.org.uk about it and if you do a lot of miles the savings are considerate. I guess this will be run solely on LPG not dual fuel?

[Anton green 12 1 Cars]

Any chance of a copy of that cd if it's not copyrighted?

Its copywritten. Everyone has asked me for copies too!!

[Guest BrainFluid]

Very interesting post Brainfluid. I was just reading in www.greenfuel.org.uk about it and if you do a lot of miles the savings are considerate. I guess this will be run solely on LPG not dual fuel?

 

I had'nt even thought about it!

 

I'm quessing that I needs to do more research.

 

Still waiting for Mike to answer my questions, lol, he must have got a bit lost since this post was move to Misc/Tech from the Xu Mods section..

 

An Only Lpg Kit would be the Dogs Bollocks though would'nt it? I've had it mentioned that with this multi point conversion is higly tinkerable and you get great preformance/economy with this.

 

Like I mentioned though I'm now tempted by a single point kit being the cheapest opiton, but we will have to see. I'm saving for the kit as of now and I DID fancy a multipoint kit to begin with....

[littlemike 0]

So how much would typical fittings cost for a Multi point kit and a single point kit?

 

So far your edging me over to the single point kit...Can you map the car to run at its best on LPG with single point? Should one be worried about backfiring with a Single point kit?

 

Would the Proper thing to do get the Valve seats hardened?

 

Thanks for the help so far Mike

 

Not sure on prices really, I don't have anything to do with that! Single point kits are £800 -£1000 fitted at a guess whereas multipoints would be more like £1400 upwards.

 

Places will sell kits to the public though and I'd say for three or four hundred pounds you'd easily get everything you need to do your own single point conversion. There's not much to them. The tank and valves will cost the most.

 

With single point kits there's not anything to map as such. All you do is set up the Lpg mixture so that everything runs correctly. Basic kits are fully mechanical (well no pc connection), more advanced kits connect to a pc so that you can set rpm changeover speeds and Lpg stepper motor settings.

 

Single point kits can backfire inside the inlet manifold if the ignition system's not 100% and it can blow air pipes open and destroy airboxes, but most of the time it's fine Just make sure plugs, leads and the dizzy caps ok. I ran a a couple of cav sri's that used motronic and jetronic systems very much like the 205's with air meters for several years with no problems at all using single point kits.

 

Has anyone come across LPG injectors that go in place of normal petrol injectors? I've seen them mentioned but never found much more than that.

 

I was thinking of a full time LPG conversion.

 

Multipoint Lpg injection systems use their own injectors for the Lpg. The petrol injectors remain untouched.

When you start the engine these systems normally start on petrol and then only switch to Lpg after a preset time delay or engine coolant temperature is reached.

 

Singlepoint kits can also work like this or sometimes they start on petrol and then switch to lpg once you rev the engine over a preset rpm (start engine, blip throttle over 1500rpm (for example) and then it switches over).

They can however also be started direct on Lpg depending on settings or on the switch type you have installed if running a non pc connection system.

 

 

Still waiting for Mike to answer my questions, lol, he must have got a bit lost since this post was move to Misc/Tech from the Xu Mods section..

 

An Only Lpg Kit would be the Dogs Bollocks though would'nt it? I've had it mentioned that with this multi point conversion is higly tinkerable and you get great preformance/economy with this.

 

Like I mentioned though I'm now tempted by a single point kit being the cheapest opiton, but we will have to see. I'm saving for the kit as of now and I DID fancy a multipoint kit to begin with....

 

Lol yeah I can never find threads once they get moved. I think they should duplicate the threads for a while and put a note saying moved to.......

 

Multipoint kits do have a lot to play with on them, but mainly just so you can get the very latest cars running ok on Lpg, not so much for gaining performance or economy (although you can a little). These kits are needed on the newest of cars because their petrol ecu's are so clever and monitor emmisions and sensor voltages so closely that if you don't use a very well sorted Lpg ecu too they will realise something's not quite right and they will throw a fault light up You have to fool the petrol ecu into thinking it has control and that nothing has changed.

 

Old pugs aren't very clever so will hapily run with a singlepoint kit!

Edited September 15, 2006 by littlemike

[Guest BrainFluid]

Thanks for the reply Mike!

 

Places will sell kits to the public though and I'd say for three or four hundred pounds you'd easily get everything you need to do your own single point conversion. There's not much to them. The tank and valves will cost the most.

 

So are you saying that I should buy the Kit and Fit it myself for aroung £400?

 

I take it that then I can have a registered Thrid Party Certify the work that has been done?

[pugrallye 0]

lol heres the strange thing.. to work on an lpg kit you have to be corgi registered. (accodrding to car manufctuers)

If you using and kind of lambda probe exprect lpg conversions to eat them, its one of those things due to heat generated through high octane fuel

Edited September 15, 2006 by pugrallye

[littlemike 0]

lol heres the strange thing.. to work on an lpg kit you have to be corgi registered. (accodrding to car manufctuers)

If you using and kind of lambda probe exprect lpg conversions to eat them, its one of those things due to heat generated through high octane fuel

 

 

 

With Lpg conversions you don't have to be Corgi registered, that's for household Lpg. Most insurance companies however will want you to get the car checked over by an approved conversion centre and obtain a certifiacte of conformity.

 

Llamba probes don't seem to die any more often than normal , maybe some are due to Lpg though? Not sure on that

 

Thanks for the reply Mike!

So are you saying that I should buy the Kit and Fit it myself for aroung £400?

 

If you're up to the job?!!

 

If not get a conversion place to do it for you. I wonder what size tank would fit in or under a 205?

 

Where would you want the tank anyway? In the boot or where the spare wheel is?

Edited September 15, 2006 by littlemike

[Guest BrainFluid]

If you're up to the job?!!

 

If not get a conversion place to do it for you. I wonder what size tank would fit in or under a 205?

 

Where would you want the tank anyway? In the boot or where the spare wheel is?

 

Well with a plumber, an aircraft mechanic and myself on team I would think so

 

As for the tank...Exactly! I just dont know. At first thought a spare wheel tank sounds good, but then I would need to put the real spare in the boot. Also I think it would be better to keep the tank and its fittings clean and safer.

 

That or keep a perfect sized tank in the boot. Could I use two small ones on either side inside the boot, weight distribution advise anyone?

 

Or Am I just talking out of my proverbial?