The V8 Owners Forum -

could the injection system be got rid of completely ie: ditch the fuel pump / ecu / airflow meter ..basicly just have the plenum / and an LPG mixer
and even blank off the holes where the injector go ?

for a while now i have not used petrol even to start the engine on ..

could then get rid of all the electrics associated with the fueling as the ignition on the old flappper is completly seperate

what do you recon ?

i did think about a carb manifold , but at least with the injection one you already have a throttle body and butterfly built in

no more restriction on the LPG side and no back fire problem either

i've just been outside ....

jammed the airflow meter open , unplugged the airflow meter and resistor pack , pulled the fuse to the ECU , put a wire from the coil + to the LPG solonoid valve and it ran sweet as a nut ...
started instantly

well the only dram back i can see is running out of gas ... as you can't ...
but i tend to fill or at least add some when it gets down to the last green light on the gauge , the other night i did run it with the red light on and it went for 12 miles and didn't run out
any other draw backs ...guys ???

Could it be that there was still pressurised fuel in the rail?

Did you run it for a while and then tried re-starting to see if it still works?

not at all mate , i ran it up to temperature then reset the LPG mixture on the vaporiser ....

it really dosn't need petrol to run ...

as they say no time like the present :

made a inline mixer out of the flat plate one i have and 2 flapper airflow meter ends bolted together



and fitted and running a treat



and no poxy airflow meter ...

i'm out on the bike tonight , but i'll take it for a drive tomorrow and test , it feels a lot crisper with that flappy thing in the way

Keith.

That sounds ingenious, you'll have us all running on LPG, look forward to you next report. Any problems tuning a high output engine and maintaining a correct Air/Fuel ratio under all conditions?

Kevin.

Hi Kevin , i use a lambada ( lol ) controlled fuel valve on mine and it seemed to work ok before , i just need to change the base settings , i have got one of those gunson thingys and that sets it up ok to start with and the control thingy does the rest ...
i'm not sure how high performance vehicles would run on gas , but when ever you switch over to LPG you disable the petrol control anyway with the mixer acting just like a very basic carb
well it do's on mine , once the LPG is switched on the ECU & PETROL PUMP / are turned off , i think thats how most of them are done sometimes the petrol pump is left running but thats not a good idea because if you happen to run out of petrol and use LPG to get home you will burn out the petrol pump as it will be running dry ...

got the petrol out today and those new 35 year old pistons are looking all nice and clean now
so they will going in over the weekend hopfully , then i'll see how it runs on 10.5:1 then decide wether i remove the rest of the EFI system
should be better on a higher compression

got any old manifolds lying about Kevin ??

bodger wrote:Hi Kevin , i use a lambada ( lol ) controlled fuel valve on mine and it seemed to work ok before , i just need to change the base settings , i have got one of those gunson thingys and that sets it up ok to start with and the control thingy does the rest ...
i'm not sure how high performance vehicles would run on gas , but when ever you switch over to LPG you disable the petrol control anyway with the mixer acting just like a very basic carb
well it do's on mine , once the LPG is switched on the ECU & PETROL PUMP / are turned off , i think thats how most of them are done sometimes the petrol pump is left running but thats not a good idea because if you happen to run out of petrol and use LPG to get home you will burn out the petrol pump as it will be running dry ...

got the petrol out today and those new 35 year old pistons are looking all nice and clean now
so they will going in over the weekend hopfully , then i'll see how it runs on 10.5:1 then decide wether i remove the rest of the EFI system
should be better on a higher compression

got any old manifolds lying about Kevin ??

I have a 6 litre Ford big block in the hot rod I'm building, and as they reputedly have climate/wallet devastating fuel consumption I was idling away at the though of sticking 'gas on that. Any websites you know of that have more details on building an LPG system, evaporators and such? I'm not too keen to spend £1000 plus on a pro LPG system, on a car that'll do a mere few thousand miles a year.

Hi Paul ... it really is so easy to fit LPG especially on ann older engine like yours or mine

have a rumage on ebay , all you really need is a tank/vaporier/carb change over switch/ pipe and a filler
with your type of engine they do either a complete replacement LPG carb ... and you don;'t use petrol at all or a mixer ring that sits on top of your existing carb to be able to use both

most of all don't be put off but people saying it difficult ..it's NOT in fact it's oh so simple

Read this Paul ?
http://www.uk-hotrods.co.uk/v2/garage_s ... /page1.php

bodger wrote:Hi Paul ... it really is so easy to fit LPG especially on ann older engine like yours or mine

have a rumage on ebay , all you really need is a tank/vaporier/carb change over switch/ pipe and a filler
with your type of engine they do either a complete replacement LPG carb ... and you don;'t use petrol at all or a mixer ring that sits on top of your existing carb to be able to use both

most of all don't be put off but people saying it difficult ..it's NOT in fact it's oh so simple

Sounds fairly basic. I'll look into it all a bit more when the car is somewhere near ready for the road. Cheers.

JSF55 wrote:Read this Paul ?
http://www.uk-hotrods.co.uk/v2/garage_s ... /page1.php

I have now mate. I spoke to Holmsey at Billing, he reckons he never uses petrol any more, just the gas.

that carb thingy is exactly what i mean ...
a very interesting site

your at a good stage there Paul to be able to tuck a couple of tanks away in the chassis ??

i only use LPG too , can't remember the last time i switched over to petrol
i was going to get rid of petrol completely but i use mine when it's really cold and i might need to warm it on petrol on a frosty morning or the vaporiser could freeze , did it to me once before so i might play safe
if your only planning on using the car on warm days and not in the winter you could easily forget the petrol side of things altogether ...
and leave even more room for LPG tanks

i'm not sure where abouts you are Paul , but if your in the london area there is a place at biggin hill who did a safety certifcate for only £50 ...you wil need one for your insurance

took the van out for a spin today and it ran fine ...

a lot smoother than with airflow meter in the way ....

You can run LPG only - I do just that in my Landie.

Chris.

What a great idea!

thankyou Chris ( did you get the package ?)

i have now removed all the electrics from the EFI part , and airflow meter too
just running the plenum as a throttle body ...i discovered yesterday i had to leave the extra air valve in place but not wired
( it uses manifold heat to move the valve too )
to make it run properly as it feeds air to the tickover screw on the plenum
it seems to run just fine