Running on Gas

[ballamc]

I am converting my morris to run on LPG and have purchased a kit. All has been straight forward and only thing left to do is to insert the gas pipe into the carburetta. The injector (if I can call it that) is simply a screw in fitting which the supply pipe connects to.

The instructions are vague to non existant on where to drill the carb to insert the gas pipe and I wondered if anyone can advise where is best? I spoke to the supplier who is very helpful but he does not know about morris minors. He advised putting the injector after the butterfly valve ie between the butterfly valve and the flange where it bolts to the inlet manifold.

Also anyone who has done this might have valuable advice or tips on the gas install in general, please share them here.
Thank you Charlie

[faversham999]

I had gas you just connect it to the airfilter with a safety valve in the air filter for incase of back fire dont want to blow the air filter up

[Alec]

Hello Ballamc,

how big is the injector? Could you drill and tap the insulator between the carburettor and the inlet manifold. That way it could be replaced at some time in the future if you take the gas kit off?

Alec

[MarkyB]

after the butterfly valve

Is clear enough, into the insulator sounds like a good idea.
Piping gas into the air filter sounds dodgy to me.

Where did you get the kit and how much was it?

[faversham999]

Thats how mine worked The petrol was swiched off automatically then the gas came on electronically
still using the throttle to make the car go on gas instead of petrol

[bmcecosse]

You do realise the LPGas can ONLY be installed by an approved fitter - and you must get a certificate of compliance - which only they can supply. You must tell DVLA and your Insurance co - both will want to see that certificate I suspect. It all sounds very vague to me - how on earth is the volume of gas controlled if it's after the butterfly ? Are you sure this kit is not intended for use on a car with fuel injection and an ECU?

[moggyminor16]

On my Rangerover we had to fit a bracket (like a spacer ) were the gas pipe fitted on to the out side to the carb just before the air filter . then fit teh air filter on the end like it was fitted before to the carb . it can not go before the carb needs to go after teh carb so that when you switch to lpg it will go in the same way like with petrol .
i will check for some photos or speak to these people they did mine on the rangerover http://www.tinleytech.co.uk/index.html

[ballamc]

Thanks to all who replied, I will try tapping the insulator, it should fit. That way if it doesn't work there then I can easily change it.

As to person who thinks this sounds dodgy, you can purchase a kit and install it yourself (for about £350 including a big tank). There is another £60 for the inspection and test. The certificate is sent off to DVLA and then the V5 is changed to reflect the dual fuel engine. I believe the diffuser will suply more gas depending on how hard the engine is running. As it is inspected they can set the system up so the engine runs efficiently. I have also been told it is statistically safer than petrol.

I have photographs of the install and I will submit it to MMOC mag with details of the reduced running costs to see if they think it's worth publishing. I should be up and running on gas in a few weeks time as there other jobs to do!

Thanks again. Cheers charlie

[mike.perry]

I bet there is not much space left in the boot

[GeorgeHurst]

I have been in discussion with a local LPG fitter about fitting LPG to my Morris, and he said that if it is a carborated car then a mixer is inserted between the air filter and the carb - before the butterfly - that way the throttle controls how much gas is introduced into the carb. There are no injectors. You manually switch from petrol to LPG from inside the car, which stops the fuel pump and allows the LPG system to release gas into the carb.

I imagine with injectors you need an ECU to tell it when and how much gas to inject. I can't see how the throttle would be able to control the amount of gas injected if it is injecting after the butterfly, unless of course the kit has some kind of ECU.

[grumpydad]

Hi
we have 4 car all running on lpg
all with carbs
one of them is Austin A35
you can put the gas in either side of the butterfly
but if you use a pipe called a spud
the gas will not mix with the incoming air very well
you should use a mixer ring
the most inpornt thing is the vaprisor
this works like a divers deamand valve
you only get gas when you suck on the gas pipe
that go to the carb
I can post some pictures if you like
but not befor the middle of next week

[MarkyB]

Pictures always go down well

Some idea of running costs would be nice too.

[GeorgeHurst]

I don't know about running costs on a Moggy, but my Dad used to drive to work in a V8 landy on LPG as it was cheaper than his petrol BMW saloon! So I'm thinking in a Moggy it will be cheap as chips! Can't wait to get mine converted

[Alec]

Hello George,

the important thing is the time it takes to recoup the outlay?

Are there not some issues with valve seat wear with LPG, worse than unleaded petrol?

Alec

[GeorgeHurst]

Hi Alec,

Yes good point, the installation I am looking to fit is going to cost me £300, and with an average fuel spend of £30 a week I think it works out at something like 6 months to make the money back off the capital outlay. So I'd day certainly within a year if the installation is a bit more expensive and the Morris is driven daily/regularly.

I'm not aware of valve seat wear, but that certainly makes sense. I should imagine though that if one has unleaded seats then it would be fine, though one is supposed to be able to run without unleaded seats on unleaded anyway I think.

The fitter did mention that if the car was run on LPG most fo the time the carb would eventually stop working with fuel, he didn't eleaborate, but I presume the jet would somehow become clogged or something like that. He said though that the carb could be cleaned to restore it's fuel function, so I don't think it's a case of lasting damage. The system I propose to fit starts and stops on LPG so as long as one keeps a full tank of gas they is little need to switch to petrol

[Alec]

Hello George,

valve seat erosion is exacerbated if the engine is driven hard, but with inserts it should be OK.

I don't know why the carburettor would be a problem, although I can see that it could be a problem with other types of carburettors with very small drillings blocking with varnish. I assume you disable the S.U. pump when on gas?
It probably is worth running on petrol for a short time at regular intervals to keep the system functional though?

Alec

[GeorgeHurst]

Yes I'm not sure of the exact details of the setup as I haven't seen it in the flesh but when you switch to gas the fuel pump is disabled and then the gas mixer comes into play (between the air filter and carb).

Yeah, I was thinking that I would probably run for a short time on petrol at a regular interval to 'flush out' any of the problem that gas might cause. However, he said it would only be the carb that would be affected so even if it did stop working on petrol it wouldn't be a huge drama to whip the carb off and clean it up.

[rayofleamington]

As to person who thinks this sounds dodgy, you can purchase a kit and install it yourself (for about £350 including a big tank).

AFAIK even though the kit is available, the installer needs to be certified if it's done legally. Getting certified isn't hard as I know someone who did it, and he's a prat.

as for running gas on a Minor - i know 2 people who have done it and both had regular headgasket failures - I'd be interested to know if this was coincidence or common with a minor.

I'm doing 600 miles a week commuting, but with 55mpg on diesel and needing my Estate boot space when not commuting, I'm sticking with my Diesel estate. if I needed more miles to the £ I'd probably buy a Yaris diesel getting 70+mpg.

[MarkyB]

Switching off the petrol pump is going to leave the carb full of fuel which is enough to get the car a short distance.
Interested to know how the engine will run when getting petrol and gas.

I've got a feeling that it may be recommended to start on Petrol then switch to gas but I may have dreamed that bit .

[GeorgeHurst]

Yeah you're right there Mark, often is the case. However I think because it is carburated system and not injected you can just start and stop on gas.