LPG system type?

[Felix]

Hi guys, while I sorta know how my LPG system works, I would like to know what type of system it is as I want to change my carb and I will need a new mixer to suit.

My gas system has a converter which takes vacuum from the air box, and one gas line out to the 'power valve' which splits into two lines which go to the mixer. The mixer just looks like two flat tubes which stick out into the air stream on top of the carb- not like a venturi mixer. I have tried googling all sorts of terms but can't figure out what type of system this is, and where to get a new mixer to suit.

I have a prime button if that makes any difference...And the only word on the converter i can see is reggio emilia?

Thanks!

[slug_burner]

have a look for it here

This is where I got a first hit

[bee utey]

Hi guys, while I sorta know how my LPG system works, I would like to know what type of system it is as I want to change my carb and I will need a new mixer to suit.

My gas system has a converter which takes vacuum from the air box, and one gas line out to the 'power valve' which splits into two lines which go to the mixer. The mixer just looks like two flat tubes which stick out into the air stream on top of the carb- not like a venturi mixer. I have tried googling all sorts of terms but can't figure out what type of system this is, and where to get a new mixer to suit.

I have a prime button if that makes any difference...And the only word on the converter i can see is reggio emilia?

Thanks!

You are running a complex converter and AMOS brand simple mixers. These mixers are effectively a venturi mixer, just look a bit different. The diagnostic is where the idle mixture control is. It will be on the converter. If you said what carby you are planning on (probably Holley?) I could advise a mixer suitable. If it is a Holley, a New Gen style mixer is most appropriate. They pop up on ebay regularly under a number of aliases (e.g. "gas hat") depending on the seller's ignorance.

[Felix]

Thanks guys! Yep I'm planning on running a holley 350- I was looking at those new gen (by sprintgas??) mixers when they pop up on ebay but wasn't sure if they were suitable. Can they be fitted into an enclosed filter housing? Just so I can run a snorkle....

Thanks!

[bee utey]

Thanks guys! Yep I'm planning on running a holley 350- I was looking at those new gen (by sprintgas??) mixers when they pop up on ebay but wasn't sure if they were suitable. Can they be fitted into an enclosed filter housing? Just so I can run a snorkle....

Thanks!

New Gen mixers were made by at least 3 different companies. Cutting up a steel carby style air cleaner and fitting it over the new gen is a fairly simple job, but you may be struggling for height unless you have a body lift. An old Holden V8 air cleaner may be most suited but they are getting hard to find these days.

Personally I don't like the new gen unless used with a large open chrome air cleaner. There are other ways, such as the adaption I made for a 2 door 3.5 last year:



The RRC air cleaner is easier to service and keep dust-leak free.

[Felix]

Ok, so I could use a normal venturi style mixer also? I already have an old holden style air cleaner on the top of mine at the moment, with the aforementioned AMOS mixer glued into it.

I was thinking of running either a RRC airbox like the one in the picture or a K&N cone type thing (which is very similar) and just a venturi ring but wasn't sure if it would work?

FYI I have a 2" body lift so I don't think clearance is a problem here. Also I'm not scared of chopping my bonnet up if I need extra height (I need extra ventilation anyway).

Why would you not use the new gen with an enclosed filter? Are they not efficient when enclosed?

[bee utey]

Ok, so I could use a normal venturi style mixer also? I already have an old holden style air cleaner on the top of mine at the moment, with the aforementioned AMOS mixer glued into it.

I was thinking of running either a RRC airbox like the one in the picture or a K&N cone type thing (which is very similar) and just a venturi ring but wasn't sure if it would work?

FYI I have a 2" body lift so I don't think clearance is a problem here. Also I'm not scared of chopping my bonnet up if I need extra height (I need extra ventilation anyway).

Why would you not use the new gen with an enclosed filter? Are they not efficient when enclosed?

The function of any simple mixer is to create a vacuum in the gas hose proportional to the air flowing through it. It's shape is unimportant, but the size/effect is. You can fit the amos or a venturi shaped mixer to a custom holley top adaptor.

Mentioning K&N in LR circles won't win you many friends. They aren't fabled for their dust prevention, especially when over loaded or dried out.

The new gen desgn is not very efficient, period. I modify it for somewhat better results. Their main claim to fame is their ability to lift up the inefficient mixer plate with a vacuum lift for petrol. This is needed on Holleys as they hate restriction from the air intake. As far as the big chrome air filter is concerned, that is what little boys demand so they get it. Then they can have petrol performance unchanged for the days at the drag races (or traffic lights). I won't fit a new gen to a straight gas setup, there is always something more efficient.

[Felix]

Oh ok, yeah the only reason why i mentioned the k&n was the fact that they do sell an air filter enclosure like the landy one.. but I agree on the filtration properties!

In your opinion, what would be the best option for me? Its a 4.4 p76 engine with a 350 holley and a snorkle. I'm not looking for huge horsepower, I just need a replacement for my current setup!

You've been really helpful!

[bee utey]

Oh ok, yeah the only reason why i mentioned the k&n was the fact that they do sell an air filter enclosure like the landy one.. but I agree on the filtration properties!

In your opinion, what would be the best option for me? Its a 4.4 p76 engine with a 350 holley and a snorkle. I'm not looking for huge horsepower, I just need a replacement for my current setup!

You've been really helpful!

I suggest you fab up or find an adaptor that gives you a 76mm (3 inch) steel inlet pipe, fit up a venturi mixer of 40 to 43mm bore size, add an early RRC 3.5EFI air cleaner and adapt the snorkel up to it.

Look on ebay for a while, your 6 cylinder holden/ford efi mixers are quite common and would do nicely.

By the way you need a balance hose from the air cleaner inlet to the converter. It means the breeze across your snorkel head won't cause mixture variations. You may already have one, you metioned something about a hose and "vacuum" which would likely be it. My picture below shows one from the inlet side of the air cleaner.

[Felix]

Ah yes, balance hose thats what it would be! I was wondering what that hose did.

Ok, that sounds like a plan then. Thank you for your help, I'm a 4th year apprentice and do you think I can find someone to teach me info on LPG? Sucks!

Cheers!