LPG

glen

Member
Has anyone fitted LPG to their V8S? If so what is the cost. Is it best to have it fitted? Also what upgrades are there for the ignition system?

Regards

Glen :)
 
I have LPG on my rover v8 powered Landrover - (I am lurking whilst looking out for my first P6). It is my daily driver and does 60 miles everyday and has done so for the last 4 or 5 years, LPG keeps the oil much cleaner and saves you piles of money too!

The 90 used to have SU's but is now injected, the principle is the same in both instances. Basically liquid gas is fed from the tank to the vapouriser unit (in the engine bay), from here lpg in gas form goes forward to mixer ring/s that feed lpg into the air intake.

On the SU's there was a mixer ring on each, on the injection I now have a single ring on the plenum throat.

I fitted the kit myself, its all common sense stuff and the hardest bit is getting the tank mounted securely. Kit cost me about £500 - but this was 4 or 5 years ago now. Needless to say it has paid for itself many times over. Later I added a closed loop control that requires you to weld a bung in the exhaust for a lambda sensor, and this gives you much better economy.

I would recommend contacting "Tinley tech" as they are very helpful, and do all manner of kits/parts etc. They will be able to advise best setup for tank etc, check out their website - I have no connection other than being a happy customer.
 
Quagmire said:
I have LPG on my rover v8 powered Landrover - (I am lurking whilst looking out for my first P6). It is my daily driver and does 60 miles everyday and has done so for the last 4 or 5 years, LPG keeps the oil much cleaner and saves you piles of money too!

The 90 used to have SU's but is now injected, the principle is the same in both instances. Basically liquid gas is fed from the tank to the vapouriser unit (in the engine bay), from here lpg in gas form goes forward to mixer ring/s that feed lpg into the air intake.

On the SU's there was a mixer ring on each, on the injection I now have a single ring on the plenum throat.

I fitted the kit myself, its all common sense stuff and the hardest bit is getting the tank mounted securely. Kit cost me about £500 - but this was 4 or 5 years ago now. Needless to say it has paid for itself many times over. Later I added a closed loop control that requires you to weld a bung in the exhaust for a lambda sensor, and this gives you much better economy.

I would recommend contacting "Tinley tech" as they are very helpful, and do all manner of kits/parts etc. They will be able to advise best setup for tank etc, check out their website - I have no connection other than being a happy customer.

I realise it was some years back, but you got it certified even though it was fitted by yourself?
 
One of my aims is to get a tinley lpg kit for sus running on my car. Looks around 600 for the full closed loop setup. When I talked to them they advised that dual fuel is unnecessary as the v8 loves lpg and starts on it happily. Just advance the dizzy for gas and leave it there!
 
rockdemon said:
One of my aims is to get a tinley lpg kit for sus running on my car. Looks around 600 for the full closed loop setup. When I talked to them they advised that dual fuel is unnecessary as the v8 loves lpg and starts on it happily. Just advance the dizzy for gas and leave it there!

Isn't the whole point of starting on petrol that petrol creates less heat than LPG when ignited? If your valves etc. heat up very quickly they become brittle so they must be hardened before starting on LPG is wise? Switching from petrol to LPG is a nightmare though, is doesn't run on both so you're waiting to empty the float chamber(s) if you have a seperate cut off for the electrical fuel pump, and when you switch the LPG on to soon it will create a whole lot of misfires when mixed with petrol. Main problem is that you can't have a good ignition advance setting for pertrol and LPG! LPG does run much cleaner.

There a special carburettors for LPG Rover V8's. I saw this about a year ago, don't remember the make though. Will look into it.
 
The point of starting on petrol is that LPG does not vapourise well unless heated (by warm coolant flowing through the vapouriser). Some cars heat up quickly enough to allow you to start on LPG but some take longer to warm and therefore you face the risk of the vapouriser freezing up and the car cutting out. Running Rover 800s I could almost always start on LPG or at least switch to petrol after just a few hundred yards of driving.

Some LPG systems have ECUs which can be programmed to cut the fuel slightly before allowing the LPG to start flowing - this allows the carburettor to drain and reduces the overlap period where both fuels are being supplied. That said, it does take a couple of seconds for the LP to flow through the vapouriser and into the mixer/inlet manifold which helps reduce the overlap time.

Fuel injected engines are often easier to do as you can cut the fuel instantaneously
 
Certification - thats a question that always throws up a big debate. There is no legal requirement to get your LPG install certified, however your insurance company will probably insist that you have it certified. Tinley (or any other kit supplier) will be able to advise you further. The Tinley instructions were good and clear with instructions on how far pipes must be from moving parts, suspension etc and how often pipework needs to be p-clipped etc.

The actual reason for starting on petrol is twofold:

- The LPG vapouriser does not vaporise the gas well when its stone cold, you end up with rich running until things warm up. Not a problem as you get no bore wash etc with LPG, but it won't run so well and will waste some gas until things get heated up.

-The vapouriser gets cold. I once measured mine with an infrafred thermometer gun thing and it got to -18 degrees C or something from a stone cold start on gas. It was quickly furred over with frost!The problem with this is that the vap unit can freeze solid which does it no good and it can also freeze the coolant pipes.

In general if your antifreeze is up to scratch the second problem will not be an issue- I have only had mine freeze on me twice and then it conks out. It was -7 or something at the time. This was a couple of years ago when we had that crazy snow. I switched back to Petrol. :shock: In general I now play it safe and start on petrol if the temp outside is around freezing or below. In summer I forget all about using unleaded.

Switching between fuels with carbs can be a pain, but nothing you cant get used to. Switch off petrol when you are cruising and can safely lose a bit of speed without surprising anyone, when it hiccups lift off the throttle and switch on the gas. Reapply throttle! :D When going the other way just switch on the petrol, when it bogs from being massively rich switch off the gas feed - simples!

Since I have been running EFI the switchover is seamless from LPG to Petrol, and the other way is almost seamless although not quite, I still lift off to stop any risk of a lean backfire during the switchover.

Heres a pic of my engine after it had done some 4.5 years of 65mile a day commuting - pretty clean eh?

IMG_20120714_113327.jpg
 
that is pretty awesome.

Quagmire, (giggety) when you were running on carbs, how did you cope with the dizzy timing change?

Cheers,

Rich
 
When I was still using the dizzy all I did was advance it a little and go for a drive on petrol up a big steep hill near me. I kept on advancing until I was getting pinking under load and then backed it off a little.

The best thing I ever did prior to efi was to fit distributorless igniton. Megajolt (MJ) really changed the vehicle and now as my MJ unit is spare (megasquirt now fitted and running both fuel and spark) I will be fitting it asap to any p6 I end up purchasing. Having two different spark maps really helps, as does the use of the Ford EDIS coil packs. Much bigger sparks than anything you get from a dizzy.
 
Megajolt is really interesting.. would also be cool to get a copy of one of the prototype briko injection systems made and power it with megasquirt.
 
Hi
I am about to have MJ filled to the Duchess. She has been running on lpg through a BLOS for 5 years. What is the best ignition setting for lpg and the best for petrol please?

Thanks
Keith
 
Thanks. I have checked RPI website, but it so full of extraneous stuff it is hard to sort wheat from chaff! It will be OK for lpg I think , but what is reckoned to be the best ignition timing for petrol?
Thanks, Keith
 
Ignition timing on Megajolt isn't a single figure, it's a map. If you are having it fitted, the person fitting it should have a base map to start with.

Richard
 
The megajolt installation is now complete and the two ignition maps have been programmed in. On petrol the engine is a dream so smooth and powerful. On lpg the situation is less good. I think I need to tune the vapourizer and the BLOS unit carefully but the engine is still silky and powerful. I will put up images of the two maps very soon. Very pleased with the outcome.
 
These are the two maps.lpg map Rover V8.jpg petrol map Rover V8.jpg
The first is for lpg and the second for petrol. I think the lpg does not give enough advance, so I will be looking to tweek it somewhat in the future when I can work out the effects.
 
My map shows the actual pressure in the left hand column, in kpa. What does yours use?

Richard
 
It'll be MAP or throttle position, Megajolt uses MAP like MS, but the tables are the other way up, with high load at the bottom.
 
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