Hi everybody this is my first post and I am proud to say I recently bought a 1971 1200 coupe with 86,000 miles on the clock. The car is a great commuter and a solid performer considering it will chirp 3rd gear if I try hard enough!
But now I have been bitten by the dat rat and been looking for some more power! I have found a 1200GX power plant fitted with twin factory carbs for sale for $950 o.n.o. I am going to buy it and begin work on it next month. I was thinking of a wade cam for peak power between 3000RPM and 7500RPM, twin 40mm webers, 2 1/2 inch extractor system, rebuilt bottom end with 60thou oversized forged pistons, some more porting on the exhaust ports and a standard 10.1:1 compresion ratio maybe more if the head or block deck need a shave to clean them up what do you all think of my plan? and how much power would I end up with? place your bets people the spanners are about to twirl

Oh brother, where art thou?

I am in Bunbury western australia or should I assume I am wasting my money with a a12gx build up?

If you crave big horsepower, then it is a waste of money.

Buy an A15 and do the same work to that,it might even work out cheaper as you will be able to get the A15 for much less than $950, and it will definately give a bit more poke than the A12.

A15 would be the best & cheapest way to go as sidedraught said.
But if you want to go with A12 theres nothing wrong with that either. If you build it properly you should get about 120HP.
A15 about 150HP. My A14 make about 140HP & thats been up for sale. 120HP may not sound much but its heaps of fun if you no how to use it. When you get the head done dont hold back get as much as you can out of it it would probabaly cost you about a grand to 1500 for somthing decent. Cast pistons are great but if you are running them on the street hyperutectics would be better as they take less heat to warm up on start up & they are cheaper so you can put the money you save in to the head or somthing.
Mark

update! I just got off the phone to the guy who is selling the A12GX engine and he will drop the price to $750 if I get up there this weekend. I will get up and buy it on Saturday then start the rebuild soon after. Now, should I get hypeuretic A14 pistons, wade cam with anti pump-up lifters, yella terra roller rockers, 36/32 webbers, mikkuni's b310 distributor jeeeeze I could go on for ever but any sugestions and tips will be very appreciated

Theres only 1 (i think) person known to date on this site that has used dual downdraught 32/36's. The manifold was an extensive exercise as was the throttle linkages (as they are on opposite sides) better just to go with sidedraught's - webers, dollertos, mikuini's, solex's etc.....

Is it a genuine A12GX? if not $750 for an A12 is wayyy over priced! And does it have the carby's, manifold (inlet & exhaust) ??

as someones signature on here (cant remember who soory ) 'speed costs money, how fast do you want to go?'

Dave

the engine is a genuine low KM (about 120,000km) and comes with factory everything such as B210 distributor, twin hitachi carbs, factory twin carb manifold, twin outlet exhaust manifold, all accesories like 12V coil, water pump, fuel pump, alternator and errr just about anything thats bolted to the engine. So what would the desired set of webbers be? I see on Ebay there is a pair of 40mm Mikunni carbs and manifold for $700 I think it's a bit rich though? and A guy in newcastle is selling a pair of 40mm dellorto carbs too I am guessing these will fit the A12GX intake manifold with perhaps an adapter plate?

Quote:
Do you know the diference between Hypoutectic and Hyperutectic pistons? The a14 piston is 76mm while the a12 is 73mm.
Finding anti pump up lifters may be a problem too as the Datsun lifter is solid, not hydraulic, and i wonder what advantage does the B310 distributor have over other models since they are pretty much the same.
Two downdraught carbs may be a bit much and you have to wonder why this is not a popular swap, or why no one makes a manifold for this conversion.

My first and strongest suggestion to you is to find someone who knows something about Datsun engines before you do something you regret, or do a lot of learning fast. Like others have said on this site, get a workshop manual.

EDIT I just read your last post. If you want the engine, then buy it as they are a lot of fun in stock trim and it might be a good idea to run it like this for a little while untill you learn something about engines in general and Datsuns in particular. It will save you some grief and money.