There has been alot of discussion on various threads about LPG and the conversion, not to mention the difference between the LPG compatible heads and the non LPG compatible heads.
So for those who have just recently joined us here is some of what we already know. If your head has 3 drill holes in it above the O2 sensor at the front, then congratulations MMAL state your car or to be more specific, your motor, is LPG compatible. If you have only one, like myself, then sorry, MMAL state yours is not compatible.
Exhaustive inquiries with MMAL have failed to establish what the differences between the 2 are.
What we do know is that the inlet valves and all the valves seats on both are exactly the same. The exhaust valves however are different. The VRX series 1 runs part MD373855 and the SX runs part MN163902. Again there is no one within the confines of MMAL or any dealers that I have spoken to that can tell me the difference between the 2 valves. Technical support from MMAL appears non existant!
The other issue that has been raised by one tech was that the bearings (both head and mains etc) may have to be different to accommodate the LPG as it has different corrosive qualities about it. I have never heard this before myself and am going to see if there are any differences in the bearings and will update appropriately.
Has anyone heard of different bearings for LPG? Sounds like BS to me personally as so many cars run LPG on standard bearings. Out to you for your tech input.

the only difference neede for lpg is hardend valves and valve seats. if you dont have these you can get a oilier dripper kit to lubricate the valves. comodores run non hardened valves and valves seats and dont have issues for a long time. fords are the same and go forever.

One last time 380matey....

If you run a full tank of petrol every 5th tank or so, then your engine will last forever, same as a VN Commodore or XSD falcan.

If you get the approved sequent 56 kit from Mitsi it uses a tank every month and a bit anyway.

It starts on petrol until coolant gets to 36 degrees C...(the time of max wear when engine is expanding temperature wise)
It also sequentially switches cylinders to petrol above about 4300 rpm for a variety of reasons.


You are going around in circles now...just do it.

One last time 380matey....

If you run a full tank of petrol every 5th tank or so, then your engine will last forever, same as a VN Commodore or XSD falcan.

If you get the approved sequent 56 kit from Mitsi it uses a tank every month and a bit anyway.

It starts on petrol until coolant gets to 36 degrees C...(the time of max wear when engine is expanding temperature wise)
It also sequentially switches cylinders to petrol above about 4300 rpm for a variety of reasons.


You are going around in circles now...just do it.

Again I appreciate what you are saying but ultimately it is my decision and all consequences and responsibility fall back on me. As such I am not satisfied acting on the information that has been supplied so far to install LPG. There are some questions that remain unanswered and they, IMO, are very important. As noone has put on LPG to a single hole head to my knowledge I am going to make sure that I am not the dumb bunny that goes ahead and stuffs his engine because of lack of information and that is why I am asking these questions, not for the sake of rabbiting on.

Well I just had a long chat with Steve from IMPCO who reckons he wouldn't put it on a non LPG head as it is just an unknown. He hasn't heard of anyone fitting a kit to a non LPG head either. Again the problem is that we don't know what the valves are that fitted to the non LPG heads and as such don't know how they are going to respond to LPG. Maybe someone else who is more game and has more disposable income than I would like to be the guinea pig. At this stage though, unless we can get more info off MMAL (not bloody likely I say!!) I wont be fitting it.
PS he reckons the drip feed hasn't proven itself to do anything.

Most of the LPG Magna's round here run on Mitsubishi non-LPG heads, as there is a dedicated 6g74 LPG head, usually found on the advance series. But I can understand your reluctance.
I've found Impco to be a bunch of to**ers myself. I would chat to installers instead.

Or you could source some LPG heads, it will pay for itself if you own it long enough.

The 6G74 heads from the advance models and dedicated gas engines use an M7 head and have LPG stamped on the head alongside where the engine lifting lug bolts on. Other 6G74's use an M2 head. Be interested in finding out if the 6G75's have M7 cast on the head as well as the 3 dimples / drill holes

Cheers

Are the heads on the series 3 the same as the 380s if so the valves may correspond as well. Anyone know?

Matey why dont you drop a message to our new sponsors they may be more helpful than MMAL and its all about LPG

Matey why dont you drop a message to our new sponsors they may be more helpful than MMAL and its all about LPG

Thanks Mecha, I didnt notice the new sponsors!

Just wondering if anyone would know if different LPG pumps would pump different amounts into a tank to get it to 80% capacity before it cuts out. (or is it the tank??). But if the LPG pumps varied, it would make it more difficult to get a more accurate economy figure, even if 2-3 litres..

I realise temperature may make some difference also.

Just wondering if anyone would know if different LPG pumps would pump different amounts into a tank to get it to 80% capacity before it cuts out. (or is it the tank??). But if the LPG pumps varied, it would make it more difficult to get a more accurate economy figure, even if 2-3 litres..

I realise temperature may make some difference also.

The automatic fuel limiter is pressure based.

My understanding is that it is responsible for what you ask.

The automatic fuel limiter is pressure based.

My understanding is that it is responsible for what you ask.

Thanks Blackstar.
Yes but i have a gut feeling that different pumps could get different amounts into a tank from empty. I could be wrong i know..
Could the speed of a pump trick the AFL a little? Like filling a tank on petrol slowly, i can get a bit extra in a tank but could it be a similar situation with an LPG pump that pumps slowly compared to one that pumps faster?

Experience between Shell and BP pump, Shell tend to pump slightly more LPG than BP, usually 2-3L more. So maybe the pump does dictate the amount of LPG cutoff.

Anythings possible...even a pump saying its given you more litres than the tank holds....LOL

Anythings possible...even a pump saying its given you more litres than the tank holds....LOL
Another variable... bugger..:doubt:

What's your avg FC on LPG?

I'm getting around 17L/100km LPG on avg 28km/hr, seem pretty thirsty to me. On petrol, i'm getting around 14-15L/100km.

What's your avg FC on LPG?

I'm getting around 17L/100km LPG on avg 28km/hr, seem pretty thirsty to me. On petrol, i'm getting around 14-15L/100km.


Both your figures seem pretty thirsty to me.

Which LPG kit are you running?


(Of course if you are sitting in traffic most of the time then your fuel consumption figures are meaningless)

What's your avg FC on LPG?

I'm getting around 17L/100km LPG on avg 28km/hr, seem pretty thirsty to me. On petrol, i'm getting around 14-15L/100km.
First fill up was 12.27L/100km
405km for 49.72L
Avg Speed 53.5kph

Both your figures seem pretty thirsty to me.

Which LPG kit are you running?


(Of course if you are sitting in traffic most of the time then your fuel consumption figures are meaningless)

I'm using Tartarini injection kit, probably because of the stop and go traffic condition here, my consumption is so bad. Avg speed are around 28-30km/hr max.

I'm using Tartarini injection kit, probably because of the stop and go traffic condition here, my consumption is so bad. Avg speed are around 28-30km/hr max.


That's not the Mitsi approved kit.....so dunno what your economy should be as a baseline.


I notice that you can buy the software kit to program it yourself though, i would definitely get this if i owned your LPG kit...

http://cgi.ebay.co.uk/Tartarini-Lpg-Autogas-System-Programming-Interface-Kit%3E_W0QQitemZ370268743014QQcmdZViewItemQQimsxq2 0091002?IMSfp=TL091002169002r36454

Thanks for the tips, but I'm afraid it might be too advance for me and i screw up the tuning as this system had been dyno tune for max low end torque & power.

I just did a experiment, trip computer for petrol at avg 43.7km/hr get me 12.5L/100km. Is this figure around the ballpark? Normally LPG are 1-2L/100km higher.

I just did a experiment, trip computer for petrol at avg 43.7km/hr get me 12.5L/100km. Is this figure around the ballpark? Normally LPG are 1-2L/100km higher.

LPG and unleaded with the mitsi kit should be pretty close...well it is for me....:cool:

Just wondering if anyone would know if different LPG pumps would pump different amounts into a tank to get it to 80% capacity before it cuts out. (or is it the tank??). But if the LPG pumps varied, it would make it more difficult to get a more accurate economy figure, even if 2-3 litres..

I realise temperature may make some difference also.

Found this.... UK web site..

*Filling notes

Filling an LPG tank is no more difficult than filling your petrol tank, but there are some differences that you need to be aware of -

LPG will change its size (density) when ambient pressure and temperature changes. In brief, you will get much less LPG into a tank on a hot day with low ambient pressure than you will on a cold day with high ambient pressure.

On top of that, there is the actual content (and therefore pressure) of the filling pump's tank to consider, if that is nearly empty then you cannot fill your tank as you would from a full filler tank and pump.

To compound things further, different filling pumps have different cut off pressures and will stop at different fill amounts. Also make absolutely sure that the car is standing on level ground - If it is leaning on a slope it will either not fill properly or overfill, both are undesirable.

Filling with LPG is not as rigid as filling with petrol. You will not get the same amount of LPG in your tank on different days, or by using different pumps. You will soon get used to fill amounts varying by a few litres from fill to fill.