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Balance pipe for LPG
Posted: Mon Feb 11, 2008 9:02 pm
by mattsluxtruck
I have tried a search on here and come up with 6000 results! After an hour of sifting thru posts I cannot find what I am after.
I have a Maverick with LPG and a snorkel. It has been fitted with an EFI Windsor with matching air box.It has a Renzo Landi convertor which I think came off the ark. It would be 1990 vintage.
Basically I am having the well know stalling problems on slow down ect due to a lack of a balance pipe between the air box and convertor.
What I need to know is where abouts on the convertor to connect the balance pipe too. There is a open port on the rear of the convertor , which appears to have a diaphram behind it. This port is threaded. Does the balance pipe fit in here?
The only other port I can see is below the sensitivity adjustment screw. It is blocked off with a allan headed bung.
Any assisitance on where to connect the pipe to is appreciated. I know it has to connect to the airbox facing the inward flow of air.
Cheers Matt
Posted: Mon Feb 11, 2008 9:18 pm
by PGS 4WD
Yes that is where you fit the balance line, the other end to the air filter assembly, or someplace that is subjected to the pressure generated by the snorkel, the gas gets blown out of the mixer without a reference, its like the petrol carby bowl vent. Make the line a decent size like 1/2 inch or it may cause a flat spot on radid throttle movement and get it retuned on a dyno as the balance line typically leans out the mixture.
Joel
Posted: Mon Feb 11, 2008 9:19 pm
by PGS 4WD
Yes that is where you fit the balance line, the other end to the air filter assembly, or someplace that is subjected to the pressure generated by the snorkel, the gas gets blown out of the mixer without a reference, its like the petrol carby bowl vent. Make the line a decent size like 1/2 inch or it may cause a flat spot on radid throttle movement and get it retuned on a dyno as the balance line typically leans out the mixture.
Joel
Posted: Tue Feb 12, 2008 6:23 pm
by coxy321
Ditto. Also, the bigger the balance pipe the better (within reason of course).
Coxy
Posted: Tue Feb 12, 2008 7:58 pm
by love ke70
minimum half inch balance line from all ive heard.
but then you ahve to clamp it down like hell on the barb that goes into the convertor...so i dunno lol
i never thought you needed the balance pipe on naturally aspirated motors?
i only ran one on my rolla coz it was running stupid amounts of boost

Posted: Tue Feb 12, 2008 8:06 pm
by PGS 4WD
You still need one N/A with a snorkel or the car will lean out at cruise and stall when slowing due to the pressure difference created by the snorkel
Joel
Posted: Tue Feb 12, 2008 8:08 pm
by love ke70
as in vacuum in manifold with shut throttle but pressurised (mildly) intake from "ram air" effect in the snorkel?
interesting, thanks for the info

Posted: Tue Feb 12, 2008 8:24 pm
by PGS 4WD
Yep thats it, as the mixer is before the throttle it is subject to the pressure and literally blows the converter closed back down the vapour line causing a lean stall when slowing to corners and stopping.
Joel
Posted: Wed Feb 13, 2008 1:48 pm
by mattsluxtruck
That is exactly the problem I am having. I am off to get the bits to put the line in this arvo.
I found that it would run out of puff at around 90km/h on the highway. I reversed the snorkel head and I can now get it to 110 before it gets a big dead spot.
From what I am reading of your Joel it appears my lack of a balance pipe could have a lot to do with this too.
Fingers crossed!
Posted: Wed Feb 13, 2008 3:26 pm
by mattsluxtruck
Well I fitted it all up. Maybe some signs of success but more of failure.
Im hoping it is just the case that it needs a retune now. I put the fitting in the airbox right next to the outlet to the motor. When it is running I can feel a very slight vacuum there. Connect the line to the convertor and the truck runs like shit. It coughs and farts when accelerating and just has no grunt at all. But it does seem to have stopped stalling coming up to corners.
Had to disconnect it and live with the stalling so I can drive the truck.
Will get it retuned. I will hook the pipe back up when I get to the gas place.
Any other ideas I should look at first?
Posted: Wed Feb 13, 2008 5:00 pm
by coxy321
You're definately putting it on the snorkle side side of the intake, and the other end into the right port??
love ke70, next time you're heading for a drive down the freeway, grab a kitchen funnel and take it with you. When your doing you 110km/h (prefferably as a passenger!!), stick the funnel into your mouth, wind the window down, and poke your head out. You'll end up looking like the michelin man. (this is just an example - dont do it. Really.)
You should be able to buy several different size barbed fittings to screw into your converter. The biggest issue i had was getting one with the correct thread in my small town. Also - check the INSIDE hole size. Several of the ones i looked at looked big on the outside, but only had very small internal holes.
Coxy
Posted: Wed Feb 13, 2008 6:33 pm
by mattsluxtruck
I have the fitting on the throttle body side of the air filter. Should I have it on the snorkel side of the air filter?
Posted: Wed Feb 13, 2008 6:52 pm
by simcoe
pics please
i'l be getting a snorkle soon and want to do it correctly
thanks
Posted: Wed Feb 13, 2008 7:28 pm
by mattsluxtruck
simcoe wrote:pics please
i'l be getting a snorkle soon and want to do it correctly
thanks
I gotta find out if Im doing it correctly first!
Also mine will be totally different to yours so I dont know if it will help you any.
Posted: Wed Feb 13, 2008 7:41 pm
by simcoe
sorry i meant some general pics of what it should look on a troll with a snorkle..
in comparason though doesnt the balance pipe go between the airbox and breather pipe on the gas mixer on any car with lpg!?