I had my A12GX rebuilt from a small one man show in Brissy.
The list is as follows,first o/s pistons and rings ,bearings,cam grind, full head overhaul,new welch plugs,timing chain and tensioner,gasket kit,oil pump stripped and checked also engine was stripped by him and hot dipped to clean fully assembled and all this for under a grand.
shop around and you will save yourself some dollars.
Ade

I would love to fit the A12GX engine in now, but I have this dream of 100-120 rear wheel horsepower in a little 1200 coupe being so fun! but to get 100-120rwhp I need it to rev to around 8000rpm and to do that I am going to need some stronger double valve springs and a suitable cam, twin dellorto carbs tuned right, and some extensive head work for power and unleaded fuel use. And while the engine is out I will replace the water pump, oil pump, timing cover, sprokets chain and pulleys with nice shiny new ones for better reliability. I was also thinking of the high energy electronic ignition that datrats sell for $466 plus $66 for adjusting plate. The car only cost me $500 from a work mate so I guess I can aford to have a bit of fun with the engine. Also with fuel going up and up it's probably the cheapest fun to be had out there

i reckon dats-hot's on the money .... if it's had a recent rebuild drop it in and see what it'll do twin 40's as 40's (not choked and jetted right) will be way big !!!

standard performance on a A12gx is pretty impressive and with the factory hitachi's you cant go wrong

drop it in the engine bay, enjoy it, save your money while you work out where you'd like it to perform better than give it a performance upgrade

that make's it 6 cents now .... this is getting costly

ha,
kinda makes me feel not so bad about the little bit of rust in my ute.

Here's an idea, why not install it as is & enjoy it for a little while. The GX is a good, well sorted engine that runs strong & was pre tuned by the factory with the correct sized carbs, correct distributor curve and so on. You will be surprised just how well they run. If you are unhappy with the performance, well, thats the time to mess with it.

If it aint broke, well, you know the rest of it.

I went and picked up the engine today for $750.
The engine has had a rebuild before it was sold to the previous owner 2 years ago, since then it has been sitting in his shed under a plastic tarp and has been manualy turned over every month in an attempt to keep the internals coated with a film of oil.
The engine and head are fitted with new welch and coolant plugs, new gaskets for the intake and GX twin exit exhaust manifold. The intake manifold, air filter housing and twin hitachi SU type carbs are very clean and in original condition. I didn't buy the mikuni carbs because I was having huge dramas finding a spare parts shop for them, instead I am buying a pair of Dellorto DLHA 40 carbs for $270 and I will need to buy a manifold to suit them and the GX oval port A series head, so if anybody has one for sale, I'm your bloke! also if any body would like to buy the twin hitachi SU carbs, manifold and air filter housing, you know where to find them!

cheers for the advise I am really keen to start my first ever engine build up since I have only been spoilt by ridding fast japanese bikes which need nothing done to them! it will be great if I can build a neat 1200 engine and have good power from it as long as I don't lose the plot and go crazy with race parts! only 2 more sleeps whoooopeeee!

$847 sounds pretty reasonable for all those bits ??!!
been thru my papers to suss out what my engine build cost .... parts and balancing/machining alone was over $1200 and then labour on top .... plus clutch and extractors and exhaust .... 'nother $500'ish .... electronic dizzy and twin 40's $1100+ .... could keep going and going ... and i started with an already modified engine .......

i think you're heading in the right direction but i gather you're not too up to scratch on the A series engines (no offence ) as a first engine build up i'd probably go along these lines - basic bottom end rebuild, new timing gear, bearings, quality rings.
head, give it a good clean, have the original double valve springs tested, open up the exhaust and inlet to match the gasket, inlet manifold(twin hitachi's) and orig cast exhaust manifold(if it's the 4-2, 2-1) too, have it decked and the combustion chambers cleaned up and go a slightly milder cam (i run a 30/66 and she's got a good kick in her and drivable anywhere, and around 100hp at the wheels) get the points dizzy regraphed to suit the cam so you can get the most out of the spark.

would be a reasonably cheap start and i don't think you'd be disappointed with the results

.....just another 2c's

I am spewing I can't find a smokey A series engine because I have just done an estimate on what it will cost me to fully rebuild the A12GX engine all up with full bottom end (except crank) will cost me $300, competition valve springs will cost $75, full gasket kit is $83, new oil pump is $99.30, new timing chain and timing chain tensioner is $41.30, new water pump is $59.45, press bent 4-2-1 extractors are $178.20 (+$100 for mandrel bent) and I am not sure what the cam will cost me (either a 49/71 profile or a 54/70 profile) all up minus the camshaft it will set me back about $847 plus postage, and with the engine starting at $750 the price is creeping up a bit. I know the A12GX head has a swirl shape intake port so I don't think I should touch the intake ports but the exhaust ports can be ported out to match the extractors and the combustion chamber opened up a bit, the block could use a hone and decking too. Ahhhhh well at least she will be a reliable fun bus to run around in!

g'day .... just thought i'd throw in m 2cents worth as i've spent the money on an A12 and can vouch for their go this is what i started with ......
full balance - pistons, rods, pulleys, crank, lightened and balanced flywheel, GX kidney chamber head fully rebuilt with new valves, double springs and guides, ports and clean up, 9.8:1 compression, clives cams grind 82 (0.050" lift) with twin hitachi (su) carbs trumpets and sox and 4-1 extractors with a single free flow muffler (not even a chrome tip)

scince then i've upgraded to electronic dizzy(bluebird) high output coil and quality leads, twin 40mm webers(30mm chokes).
i've recently had it on the dyno and its putting out around 100hp at 6000rpm, revs out to 8500 without a drama and still has pull, and completely drivable on the street in traffic and on the freeways. all up i reckon i've spent near on $4000 give or take a couple hundred and i'm real happy with what i've got

i've also had a similar A14 and the biggest thing i can say the difference was is wheel spin .... A14'd spin thru 2nd and chirp 3'rd no probs and had a little more pull - A12 doesn't come close but seems to run better thru the entire rev range

either way you go i don't think you'll be disappointed .... good luck