http://www.helmarparts.com/Carburetors_s/83.htm

Anyone know if the nissan H20 or toyota 4y carb is similar to the stock datsun pattern? Its an interesting proposition for LPG setups looking not far from stock.

Here is the j15 one and a bit small at 31.75mm



Here is the big Mitsubishi 4g63 one 44.45mm!



and another big daddy for H30 Nissan at 44.45mm!



and lastly at 48mm!!!!! for side-draft (would be nice with 2)
http://www.helmarparts.com/v/vspfiles/photos/CA100-126-2.jpg

I have done something simular with mine. It's an impco 125 mixer with a impco J convertor.

Looks a neat setup is the J converter like a throttle body or did you use your carburettor baseplate as one?

I used an origional nikki base and made an adaptor to fit the mixer. The J convertor is just a 1/2 version of the daddy model. Like a B2. Although it is a basic setup it chews around 18 litres to 100km approx. Still beats the price of petrol. I am going to change the setup again soon. Same mixer etc. New manifold.

I used two of those throttle plates, ca125 mixers, twin SU manifold on a L series.
It was very difficult to get mixtures lean enough, had to run extra idle mixture shims(fitted in the air valve).
This set up even when properly dyno tuned was not as responsive, not as economical and only marginly more top end over a single CA 125 mixer...I also tested a CA 200 mixer but the 125 was better..

But gas injection made another 20KW over a CA 125 mixer on my A series..

mmm sounds like the info the guy at the dyno day for oz dat was wrong, he said was running lean, told me to richen it. Took it back for a tune to richen it and af mixtures were ok. Made it richer and drove like a bag of poo. I lean it off agin with mixture srcrew where it was(he marked it for me in case was cra) and better.

Sounds like im having the same dram mixtures as you did with the twin lpg set up. cant get lean enough

Stoich mixture for lpg is leaner than petrol. 15.7:1 for lpg, 14.7:1 for petrol. Mik. Half the reason that your engine is so hard to tune is that the carbys are too big for the stockish motor to start with. But the finer tuning has sorted it to a degree. You can't have power and economy with lpg. Trade one for the other. Unless you go turbo.

the A15 was a forklift motor too, so there are complete lpg sytems that bolt on. not sure they're suited to driving a car since the industrial A15 was rated at like 42HP.

Propane seems to run 'lean' if you want any power out of it. also propane likes higher compression that most A series motors have.

I actually have too much carburettor, it's about 60mm with a GA16 throttle body,it needed a restrictor put in the intake to get it more vacuum signal.

using omvl equipment, seemed more suited to cars than impco.

i've struggled with fuel economy ... 18l 100km is about 15 mpg, thats' about as good as i've ever gotten in the city.i've had 30 mpg+ on the highway. i look at it as lpg is 1/2 the cost of petrol, so i'm getting 30 petrol mpg even at the worst ... 20 petrol mpg city and as good as 60 petrol mpg highway.... creative accounting? not any more than a hybrid...

the short answer is a turbo... lpg likes 12.5:1 compression, economy should be much better then, if you can keep your foot out of it. debating just buying the turbo already and getting started...

yeah already new had too much carb for the A15 so L series should naturally balance that one out eventually. just trying to sort out some tuning in the interim.

Lpg responds to turbos quite well as in it's natural vapour state it blends poorly with air. When you force it to blend it propegetes a better flame front.