What carb and diff do you have too!

I'm asking because running LPG kills a bit of my mileage, and i'm wondering what the best can be.
i'm up to 16ish now around town with 700 feet between stop lights and a drag race at every green... people here drive craazy!

Around town numbers mostly, I can get 33mpg at 75mph and still get disappointing #'s in town.

Currently I know my issue with running lean has to do with the amount of hot water my vaporizer is getting, otherwise it wouldn't be perfect lambda all over town and then get lean after a bit of highway driving, then run rich after sitting running for a bit to build up heat, then go back to lambda again.

Whee! modifying everything is so exciting!

other fun things, moving intake a bit to prevent the 90 degree bend from bouncing and making things stuff up. It seems too, that having too short an intake can be trouble too, i have a cone filter on the vapor mixer and a 90degree bend intercooler hose to the throttle body. I think one of those k&n cold air filter pods would fix that right up... never seen one... they're pretty cool.. k&n apollo

[img]http://knfilters.com/search/product.aspx?Prod=RC-5052AS[/img]
...hmmm why don't the built in image tags work?
yeah... best around town mileages, reasonable #'s over multiple tanks of fuel.

So far my best MPG is 49 at 65 mph. Absolutly stock A14, five speed, h150 3.70
Nothing aftermarket, yet. but I have screwed with the carb, timing and perfect valve adjustment. too bad it's only about 28 around town.

dont forget if its premium youll get more

If you run unleaded do you have to get the seats changed in the head, Or will they take unleaded due to the fact they were designed for leaded...??

There was, is and will be many debates around the unleaded vs leaded issue. Many people say that they haven't really seen a detrimental effect on older engines, even ones with cast iron seats. I can only say that I see a lot of old cars fill up with unleaded, and not many that has issues.

But back to your question, only right at the inception of the A series engines, I think they used some kind of bronze compound seat(some of the older members might be able to enlighten us with some more info here), from there on they started using steel. So unless you have a very, very old one, you don't have to worry, it'll be fine with unleaded. And no, if you would have had problems, it would have been because it was designed for leaded, and not unleaded.

The reason you might experience problems, is that the lead, other than lift the octane rating, creates a softer landing when the valves close on the seats, and for the rings on their lands. This stops the lot from wearing away at a fast rate, should they be made from softer compounds. In theory at least that is.

Anyway, if you run it with LPG, there is no cushioning effect whatsoever. Which is also why I doubt that running your older car with unleaded would have to much of an effect on it's lifespan...

Driving 65 is too hard, i get up over 80 on the freeway here just to keep up.

I'm using new everything.

Datsun made many A15's for forklifts that run propane, so that's not even an issue.

LPG also doesn't wash the oil off the cylinder bores or get the oil dirty nearly as fast.

b210sleeper you inspired me about 12 months ago to do some heavy research into lpg and the datsun and it is going to happen within the next 4 weeks due to my petrol and needle issues with my su's and the inavilability of reasonable priced parts.

Im going twin su lpg set up and just strugling to find a tank that will fir the b110 sedan between the rear wheel arches. approx 800mm

This would give me a lpg tank of 36lt useable gas, might be able to fit a 47lt tank with a bit of massaging for the required crlerance by law.

36lt tank would give me a rang of approx 200kms, 46lt approx 300 to 350km. Way better than my efforts on petrol.

it takes approx 1.2 to 1.4 times the ammount of lpg to the quivelent of petrol to make the same power/ fuel economy compared to petrol. eg 1 lt of petrol burnt would be 1.2 to 1.4 lt gas.

Im planning on setting it all up then skimming the head later on for more compression to take advantage of 110 to 114 octane equivelent here in aus for lpg.

my only regret is not getting a bigger tank.

I cut out the spare tire area above the gas tank and built a nice frame bolted between the rails, so upgrading is fairly easy.


Mine is 30 lt or something like that, and in town 100 miles between gas is a bit too often.

I'm tempted to switch to a propane injection system, that will help the mileage a little.

propane power needs a turbo to work best.

The higher octane is nice! Pass everyone on long grades when their ignition starts retarding. High altitude seemed to be less of a problem with propane too.

My best is about 19.02km/l or 55mpg cruisin at 100km/h, i average about 49mpg or 17.2km/l at 115-118km/h (true speed not indicated) running on 98RON with A12, 5 speed O/D and 3.7 H165, 185/60R13 tyres, in a 1200 ute.

mmm 100miles = 160km around town... not too bad compared to a rich running petrol a15 with su's getting about 220km from 35lt petrol