Thread: LPG into 3.9

Simon

If you are using the MAS and ECU from the Disco you need to fit the LPG mixer before the MAS.

Yes the LPG mixer is a standard part that fits on the MAS between the intake flange and the MAS body. I have one around somewhere but may have to use it on my SIIB/Disco1 hybrid.

Remember you also have to move any crankcase breather to the air-filter side of the LPG mixer. This is to prevent an explosion in the event of crankcase flame bypassing the flame trap.

Diana

BTW: You should try to have the coolant lines as low as possible so you avoid a coolant air lock in LPG converter lines. Yours look a little high and possibly the highest point in the system, avoid this if you can (I couldn't, because there's too much junk under the hood of my RRc).

Thanks for this Diana, some really good points there - I hadn't even considered the breather!

Just to clarify, it would setup as Plenum, LPG, PCV, MAS and then the airfilter.

Slunnie you want an impco 200 or 225 mixer, both inline mixers 200 is a 90 deg L shape and the 225 has inline inlet/outlets - both will work with the converter you already have.

And re mount the converter so the primer button on top is horizontal , i had mine high up on the inner guard in my rangie and never had any airlock problems mounted that way.

Originally Posted by loanrangie

Slunnie you want an impco 200 or 225 mixer, both inline mixers 200 is a 90 deg L shape and the 225 has inline inlet/outlets - both will work with the converter you already have.

And re mount the converter so the primer button on top is horizontal , i had mine high up on the inner guard in my rangie and never had any airlock problems mounted that way.

Like this -

Thank this Loanrangie, the Impco 225 looks like its probably the part that I'm after so that it exits similar to Stirlsilvers - and will also allow me to manage fitting an airfilter box and snorkel. I'll hunt one down. Thanks for the tip also re the converter - now I know what that button is.

I just popped the bonnet on my 3.9 and it still has the breather fitted to the MAF and the mixer on the plenum.Slunnie I bought buy accident resistance plugs which are the wrong ones and mine has never run better,I also wound in the base idle screw,the small one on the converter till it sounded right then set the mixture by ear as well.You no doubt now this but I've had four LPG vehicles and the electrics must be top notch,I replace everything once a year and set the mixture so she runs good and glue the two screws and she's runs very well,no hunting idle,no rough idle she's all good. Pat

Thanks for this Pat, actually I know very little about LPG - it's not something that I've thought much about. It just seems to me to be an incredibly simple setup that doesn't even alter mixtures depending on what the engine is doing.... anyway, they seem to work.

Thats the reason for the big price differences.Yours is the fixed rate system so there is no adjustment for engine load-revs.You will have to set the tune to suit the driving you do,generally running slightly rich at idle works better with that system as they lean out under load otherwise.My series three had the same set-up and I had an in cab timing advance kit so I could run 6 degrees on petrol and 16 on gas. Pat