ggzilla Posted June 21, 2014 Report Share Posted June 21, 2014 Richer means faster. A12 carb has small venturis A14 carb has large venturis, therefore flows more air, therefore makes more power over 5000 rpm on an A12. If you need a new carburetor, a Weber 32/36 is larger still and makes more power at 6000 rpm. Quote Link to comment
ggzilla Posted June 21, 2014 Report Share Posted June 21, 2014 A14 carbs in USA are tuned from factory for 14.7:1 cruising air/fuel ratio (for catalytic convertor). However maximum power is made at a richer 12:1 approximate. The power valve enriches the A14 at full throttle but not that much. It is an economy engine. But it is easy to rejet for power. For a turbo you will need to rejet the carb to make the engine last. A12 is only slightly than A14 and is enough to run smoother. Still not rich enough for safe turbo operation. Quote Link to comment
ggzilla Posted June 21, 2014 Report Share Posted June 21, 2014 USA jetting A12 1971 Main jet 98, air jet 80. Jet/venturi ratio = 98/20 (4.9) A14 1975-1977 Main jet 95, air jet 102-104. Jet/venturi ratio = 103/23 (4.5) With smaller main jet and larger air bleed you can see how the A14 carb is much leaner. Quote Link to comment
ggzilla Posted June 21, 2014 Report Share Posted June 21, 2014 The secondary barrel jetting for Australia 1980 A12 Secondary main jet 150. Air bleed 80. Jet/venturi ratio = 150/26 (5.8) 1980 A14 Secondary main jet 150. Air bleed 60. Jet/venturi ratio = 150/27 (5.6) For this market the A14 is richer at high air flow (smaller jetting but with smaller air bleed = richer). A12 and A14 use the same power jet which works at full throttle. Quote Link to comment
datsunfreak Posted June 21, 2014 Report Share Posted June 21, 2014 A12 carb has small venturis A14 carb has large venturis, therefore flows more air, therefore makes more power over 5000 rpm on an A12. On my '75 B210 and my '80 210 we used 1200 carbs and just switched out the main jets (put the A14 jets in the A12 carb). As I recall, they had the same size venturi on all 3 carbs. And both times, throttle response and "power" got better. Of course both A14 carbs were junk, so... :rofl: Quote Link to comment
prophet1012 Posted June 21, 2014 Author Report Share Posted June 21, 2014 thanks for the detailed explanation , it is very helpful. A12 is only slightly than A14 and is enough to run smoother. Still not rich enough for safe turbo operation. the a14 i mentioned is a replacement engine until i get everything ready on the a12 (re-machining it flat, parts from abroad, fitting the turbo ect). i don't intend to turbo the a14 being that i have only one and they are SUPER rare in Malta. I got almost everything for it to run including the clutch kit i bought today. the only thing it is missing a carburetor. now if i understood you right , an a14 will run on an a12 carburetor but not to its full potential because tha carb on an a12 does not ha enough airflow to Fuel it at higher rpm than 5000rpm. I can get an a14 carb off ebay from china for about 80 euro but i don't think they are reliable. What do you recommend i should do ggzilla? with regards to the carb problem Quote Link to comment
prophet1012 Posted June 21, 2014 Author Report Share Posted June 21, 2014 On my '75 B210 and my '80 210 we used 1200 carbs and just switched out the main jets (put the A14 jets in the A12 carb). As I recall, they had the same size venturi on all 3 carbs. And both times, throttle response and "power" got better. Of course both A14 carbs were junk, so... :rofl: do you have the sizes of the a14 jets? maybe I can buy and fit such jets to tha a12 (off a b310) carb i have Quote Link to comment
datsunfreak Posted June 21, 2014 Report Share Posted June 21, 2014 do you have the sizes of the a14 jets? Nah, I'd have to pull them out and have a look. At which point I might as well mail them to you... :rofl: If you have a Nissan dealer there in Malta they may be able to sort it out for you? Quote Link to comment
ggzilla Posted June 21, 2014 Report Share Posted June 21, 2014 A12 carbs have 20/26 venturi B110 spec A14 carbs have 23/26 venturi. The bores are the same size at 26/30. Quote Link to comment
ggzilla Posted June 21, 2014 Report Share Posted June 21, 2014 The common A14 jetting is listed above. There are a million variations, see Datsun1200.com Quote Link to comment
ggzilla Posted June 21, 2014 Report Share Posted June 21, 2014 the a14 i mentioned is a replacement engine until i get everything ready on the a12 ... if i understood you right , an a14 will run on an a12 carburetor but not to its full potential because tha carb on an a12 does not ha enough airflow to Fuel it at higher rpm than 5000rpm. I can get an a14 carb off ebay from china for about 80 euro but i don't think they are reliable. What do you recommend i should do ggzilla? with regards to the carb problem I would use the A12 carb unmodified - it will run very well. Its temporary, and how often do you rev over 5000 rpm? Quote Link to comment
datsunfreak Posted June 21, 2014 Report Share Posted June 21, 2014 I would use the A12 carb unmodified - it will run very well. Its temporary, and how often do you rev over 5000 rpm? What he said. Quote Link to comment
ggzilla Posted June 21, 2014 Report Share Posted June 21, 2014 And at 5000 rpm it will still make more power than the A12 at 6000 rpm. Quote Link to comment
prophet1012 Posted June 21, 2014 Author Report Share Posted June 21, 2014 Very very very often, we use it (the red sunny not the silver) to "drift" in our race track, with welded diffs and skinny tires. But until i get the a12 turbo sorted i will take it easy, afterall i want the a14 to last. I don't need to rev it hard to get is sideways since the a14 is more powerfull than a12, andso far i managed to keep up (and often be better) then some of my lads with toyota ke70 with 4k engines 1 Quote Link to comment
prophet1012 Posted June 21, 2014 Author Report Share Posted June 21, 2014 I hope i don't lose your respect guys since i mentioned drifiting and such haha Quote Link to comment
ggzilla Posted June 21, 2014 Report Share Posted June 21, 2014 Turn in your Ratsun membership card lol Quote Link to comment
datsunfreak Posted June 22, 2014 Report Share Posted June 22, 2014 I hope i don't lose your respect guys since i mentioned drifiting and such haha That's why my car has an A15, a welded diff, and skinny tires... :rofl: Quote Link to comment
prophet1012 Posted June 22, 2014 Author Report Share Posted June 22, 2014 Nahhhhhhhhhhhhh too valuable xD thanks for the help guys, much appriatiated. I will fit the a12 carb and look for a14 jets. I will inform you datsun freak if i the nissan dealership does not import them for me. Btw if you have an a14 carb for sale i am more than willing to buy one Quote Link to comment
ggzilla Posted June 22, 2014 Report Share Posted June 22, 2014 Use the A12 jets in the 1980s A12 carburetor. It will have the correct air-fuel ratio for the A12 or A14 Datsunfreak was using a 1971-1973 carburetor which is significantly different. Quote Link to comment
prophet1012 Posted June 22, 2014 Author Report Share Posted June 22, 2014 Use the A12 jets in the 1980s A12 carburetor. It will have the correct air-fuel ratio for the A12 or A14Datsunfreak was using a 1971-1973 carburetor which is significantly different. that means use your stock a12 carb from the 1980s b310 right? Thanks Quote Link to comment
prophet1012 Posted June 22, 2014 Author Report Share Posted June 22, 2014 Hi lads if i must ask. Does the starter motor of an a12 fit on an a14? because while checking the parts i have i noticed i did,nt have a starter motor for the a14 Quote Link to comment
datsunfreak Posted June 22, 2014 Report Share Posted June 22, 2014 Should work just fine. Quote Link to comment
ggzilla Posted June 22, 2014 Report Share Posted June 22, 2014 They are exactly the same. * Same starter is used by A14 and A12 * 1971 starter is not as reliable as 1982 A12 starter. * Automatic starter is stronger but slower. Can be used on manual transmissions. Good for high compression engines Quote Link to comment
prophet1012 Posted June 23, 2014 Author Report Share Posted June 23, 2014 thanks lad, then i think it is set. I only need to start the engine up before i install it in the sunny (since it came off a voilet) and finally i will have an a14 xD i hope the termostat housing is the same (it should be as i measured them) on both a12 and a14 as i don't have one with the a14. Also i need a tempreture sensor but they are easy to find i suppose Quote Link to comment
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