LPG conversion

[stradlater]

Firstly, "Imperial Welch Plugs"? I assume you mean a welch plug you could purchase from a repco or somewhere?

And what's stag?

[timbosaurus]

With a dedicated injection system, LPG is a great option. I want to do some work in the future with this and see if the real world benifits live up to the theoretical ones.

In my opinion:

-LPG has a higher octane rating, which means you could theoretically run a forced induction high-comp motor and benifit from the responsiveness that comes with that.

-If you inject the liquid close enough to the valves (preferably right behind the inlet valve) the vaporising cools the inlet air, effectively working as an intercooler. I cant quantify HOW much cooling this provides... i dont think it would replace an intercooler... but i'm interested to find out.

-LPG also doesn't wash the oil of the cylinder bores as much as petrol does, this adds to longetivity of the engine.

-LPG is cheaper

-The concept that a litre of LPG wont get you anywhere as far as a litre of petrol comes from the non-optimised mixer days, where the engine had to run on both fuels. If you run a higher comp and/or forced induction engine optimised for LPG only (to suit the higher octane) you will get very close to, if not the same, litres/distance as a petrol setup

Add to this the benifit of being able to control management maps like EFI engines and you will start to realise why i want to play around with near-direct LPG injection.

Time will tell!

Timbo

[stradlater]

Sounds like a plan you have there boss..

I have it upon very reliable info that there is an uprated type of converter that is far more responsive than the typical 'modified B2' converters...

May be no need, other than the mapping option, to go for LPGFI

[Grega]

strad. holden v8 welch plugs if memory serves
stag is the red gooey shit you put on welch plugs before you tap em back in the block. stag jointing compound

timbosaurus. not much cooling benefit from LPG if injected as a vapour matey. if injected as a liquid though, very different story...

[mrshin]

When plugging injector holes in the past, I've just used pieces of aluminium from the scrap metal place, chewed down to sized on the lathe and pressed in. I guess having a lathe helps;-)

[timbosaurus]

timbosaurus. not much cooling benefit from LPG if injected as a vapour matey. if injected as a liquid though, very different story...

That's what i was getting at mate

i mustn't have made myself clear

So you have any idea HOW much cooling it provides? Is it comparable to running meth?

Cheers
Timbo

[Grega]

all good

i don't to be honest. when my celica is sorted with the turbo i'll pop a thermocouple in my LPG low pressure supply hose and see what temp it is. would be good to know hey

comparable to meth? no idea..

[timbosaurus]

are you injecting liquid or gas?

[Grega]

neither. GRA

i *may* look at vapour injection. see what shinny can get injectors for

[timbosaurus]

Gotcha... i'll keep looking towards liquid injection.

[takai]

Out of curiosity, if one was to go dual fuel, then would it make more sense to run say 5% petrol in with the gas, mainly to keep the injectors lubricated? From my understanding the gas will easily increase the burn of the fuel too.

Oh yeah, and while im on the topic i was looking at an interesting gas addon to diesel cars. Basically they use a smaller cylinder and only add in about 10% of the fuel to increase fuel atomisation and burn. Anyone else looked at that style? I reckon if i end up getting a Surf ill go down that option too.

[wagonist]

I've heard of the diesel/LPG before overseas, but never here.

I'd be wanting someone experienced in that area before I let them loose on the Caldina engine.
Though the thought of not getting the wooden spoon at a dyno day appeals

[schnitzel]

Diesel/Lpg has been here for years in commercial applications. I used to run Diesel Generators on trains in the mid 1980's. That is LPG powered diesel lombardini Generators. Used to use 2 45 Kg bottles every 16 hours.

Have also seen them used in stationary situations.

Regards

[wagonist]

That's still a little different to a small engined fwd import.
Most people are worried by the fact it doesn't look like anything here, let alone be powered by an engine that isn't widespread here either.
Besides, apart from a tank that sits in the spare wheel well, I don't want to loss any carrying space apart, I already carry a full size spare up in the back because the spare wheel well only fits a space saver.

[stradlater]

you may lose the dyno days, but on the flip side you could probably tow everyone home when they break down! :-)