to be 100% honest a12s dont go ,youd be better off buying an a15 for a little more than an a12 and then give it a rebuild shave the head ,cam and a dgav weber as mentioned before ,will go heaps better as its already more displacement ,and has the head youd want if you were to build an a12

its up to you realy but ive had both a hot a12 and now an a15 and the a15 #OOPS#s allll over the a12 ,it sounded cool but thats about it ,unless you spend heaps on them they dont go

cheaper to just go for an a14 or a15 and it will be cheaper in the long run for the same power

ps bige is awesome for parts A+ for service ,highly recommend using him ,realy knows a series motors inside and out!

thanks heaps 1200ute.

Bige, Im on the Gold Coast, Could you please send me PM with what parts you offer? Thanks, Zak

where are you located, i do rebuild kits. cheers

didnt i go over this earlier?
Your local mechanic should be able to source all if not most of the parts needed for your engine, pistons, gaskets, bearings, spark plugs, leads etc...
Repco/Bursons have your general consumables such as oil filter, air filter, fuel filter, radiator coolant, fan belts, oil etc.
Pretty sure ACL does pistons/gaskets/bearings too.
Otherwise contact Auto surplus as they will have the bits you need if notbe able to source them... everything inc. oil pumps, water pumps, from top to bottom...
Otherwise if you're after specific second hand parts from here, put up a wanted post in the classifieds.

Thanks a lot guys, im an apprentice fitter and turner so i can do the measuring with telexcopic gauges and mics. If any of you have the parts or know anyone/where that has them that i can buy them from it would be greatly appreciated. Thanks again.

Well said^^^ that was sorta what I was trying to get at...
Also if you can't build the engine yourself a mechanic should be able to build the bottom end for aroundte 250 dollar mark....

I'd use the Weber 32/36 and a moderate cam with dual valve springs. If your current bores are terrible worn then go with what ever size flat tops you can find cheaply, if the bore are fine then just re-ring it. As far as the cylinder head goes you can clean up the ports, on a stock head the valve seat actually protrudes into the port about 1mm, just getting the seat flush with the port wall will increase flow a lot.

So basically if you don't need to bore the block don't, regrind the cam to a moderate spec (260 duration .375 lift), 32/36 weber, Header/extractors and larger diameter exhaust. Now as has been mentioned this will get you about 80-85HP range which is what an A14 puts out. If you can build the engine yourself than that's a plus. Also if you can find the bits used off this site or Ebay etc. then that will help as well. Even as cheap as I find stuff on the used parts market I would expect to be into the motor for $400-500.


Tom

Oh I thought thought the H89 head was a lot higher comp, or is it a lot higher than the h75 head? O_o

H89 is same compression ratio as stock A12 head, so don't waste your time there.

H89: 29-31cc
A12: 27-29cc

However, H89 makes superior power above 3000 RPM. It is highly recommended unless you don't like to rev the engine in daily use.

Yes, flat-top pistons are the best way to gain higher compression.

To make the most HP, don't worry about Compression Ratio, but instead fit larger pistons. Regular oversize pistons (0.5 mm) will gain no noticable power. A14 pistons are 3mm larger diameter, and will deliver far more power than Compression Ratio change.

Otherwise, simply put new rings in the A12 and enjoy. Most blocks do not require any machining of bores unless you are fitting larger pistons.

You'd be surprised how hard an a12 can go!
Your best bet is to drop into a/few local mechanics and have a chat about what recommendations as they will be able to guide you the best, especially price wise...
My mechanic starts at $80. i already know before i go there it will cost me 80 dollars before he looks at it.
ACL pistons are pretty generic...
I would use all your standard rods, crank flywheel etc. It all depends how much money you wanna spend. More money means a better a12.
I would recommend having the block bored and honed, a nice set of flat tops, have the crank, rods and pistons all balanced.
Have the flywheel machined and lightened a little.
Then you can do some head work, this is all good and well but it costs money! I spent a good grand having all my machining done which included everything being balanced, had the head shaved and also had the bottom end assembled.
you can have a standard cam reground to be a little bit more lumpy but id keep it mild, as a cam tha picks up at 5-7 grand would be terrible to drive on the streets...

A much cheaper alternative is to wait a little and hunt down a cheapish a14/15... an a14 has been known to rock up from time to time for between 450 and 600 dollars... Simple conversion if you have a late model cross member. Or modifying the engine mounts isn't too hard but from memory modding engine mounts will cause an engineers cert. but dont quote me.
If you ask around for brands put a few other maybe more specific posts up to the part you're looking for on here and the gurus should be able to help as im still learning... if anything compared to some of these guys i look like nothing! haha

When it comes time to buying gasket and what not go to Auto surplus in Mitcham
http://www.autosurplus.com.au/
Let them know Eddy from here sent you. They will sort you out.
They should pretty much be able to get you anything...
Otherwise you can contact member Bige, he builds a series race engines and will be able to answer any and all of your questions much better than me!!!
One thing to keep in mind, none of this is a cheap exercise always remember that!