Ok so i have an extensive text book(the bible) for lpg conversions called the mechanics of lp gas for internal combustion engines. This is the book from the Sydney institute of technology and is the text book supplied to train Lpg gas fitters. In this book it states to mount the converter/vaporizer away from the exhaust manifold unless a heat shield is used. Now my query is, with the Falcons most if not all the converters ive seen have been mounted near the exhaust manifold, now this isn't a problem as they have a heat shield, But, are they also placed there to help the converter heat up earlier rather than just reallying on the heat from the coolant?

or

Are they just mounted there because of the extra room available?

Whats your thoughts.

Also, is there anything stopping me from putting the rear hose from the tappet cover into the balance line hole on the mixer to prevent gas from going into the engine? Probably should mention its an impco 200.

I think its cause of space. In my EF I just put a gas system in and I wasnt keen on having hoses running back and forth over the exhaust. I pulled out the air box and put a pod filter on. I know its not getting cold as air in, but it suited my purposes so I could throw the converter in there, and hopefully blow the pod filter off in a backfire. Sick of trying to fix cracked air boxes on my EB. I dont think the heat from the exhaust would hurt it, its got plenty of air flowing through there and coolant running through it

If I understand the balance line question correctly, you should put that hose into the up stream side of the intake air tubing. My EB had a spot for it on the mixer just up stream from where the gas holes were. Havnt checked what the EF has yet, the installer fitted the mixer. Your trying to avoid gas going into the crakcase in the event of a backfire?

Well you know how the engine "breaths" some times it will draw air as well as blow bye. So if you have the crank case vent in between the mixer and the intake the engine could suck in gas and if its ignited BOOM! inside the block. i figured the balance line is before the mixer (ever so slightly) so i could plum it into there. But yeah i didn't think of the back fire issue.

The rocker cover rear hose needs clean air - so anywhere 'downstream' of the mixer is fine, usually to a fitting on the airbox upper lid. The pcv will suck air through the cover, so a gas charge in there constantly would be a big risk in case you do get a backfire - if the PCV is plastic, it will most likely shatter, if these pieces get into the chain, cam sprocket - absolute disaster. Seen it first hand - not pretty.
With BBM engines, the converter usually sits near the RHS suspension tower, log manifold near the LHS suspension tower. AFAIK, space and bonnet clearance are the main factors.
The converter should sit in a position just like the front wheel (if that makes sense) - large hose to the mixer at the bottom - mainly to reduce comtaminants in the gas staying in the converter. Other reason is this positioning reduces inertia (braking/acceleration) on the converter diaphragm.

Cheers guys. So there is a risk of gas entering the engine if the rear rocker cover hose is connected to the balance line on the mixer. bugger, i thought that was a good place for it. Ive got the converter mounted where the washer bottle used to be. I now have a new washer bottle on the drivers side near the brake booster. I mounted the mixer in the 90deg part of the inlet from the airbox to the throttle body. I just wanted the least restriction possible and the shortest vapour line i can get for good respounce. Ill do a build thread when i get the time with some hp results.

What car is this on - I'm picturing the XR6 ??
You can still pick up a fresh air spot on the induction tubing - just needs to be between mixer and airbox.

Yeah mate on the XR6. Ive got a few barbed fittings some where, i might tap one into the intake near the air box.