I have managed to get my xxy 1500 running and the only work i did was putting oversize pistons and gapless piston rings. With that said how would u extract more power before cylinder head porting and major mods, so how can you tweak a 1500 motor?

Realistically speaking you can get about 100bhp(ish) from the engine using a cam change, exhaust and induction mods.

The cylinder head is the key to the performance though - a properly gas-flowed head with bigger inlet valves coupled with the other parts would give closer to 130bhp at the wheels (about 150bhp at the flywheel) but the original carburettor is completely inadequate for that. You'd probably need to look at a serious overbore and longer stroke to achieve that too.

Without forced induction the biggest (proven) power figure for tuning was approximately 190bhp at the flywheel by Dallara but that had just about everything done to it, including a custom 16v head and fuel injection. It would have been totally undriveable on the road too.

Best bet for non-serious modifications would be a proper exhaust manifold, electronic ignition and a re-jet of the carburettor. Getting hold of a decent camshaft could prove pretty entertaining as the cam is already pretty aggressive.

Thanks jimbro you are a guru at these things, if I get my local engineering firm to make a custom inlet manifold to accomodate twin datr 32mm carbs will that boost performance or it will be a big waste? Also wat exhaust sizes do i need to make a performance exhaust. again will an electronic distributor from a fiat uno pacer 1400 do on the 1500 motor?

Wouldn't bother with twin datr's - these are progressive systems built as much for economy as performance, if you want performance you need to look at dcoe's or dcnf's. I'm not saying it can't be done but for all the hard work involved there are better choices.

The exhausts are available from CSC - like this: http://www.eurosport-uk.net/shop/in...ducts_id=268&zenid=fikt5d9gidnsm6un34fk1g5gs5

The later electronic ignition systems (like the one you mention) are near enough a direct swap-in although the length of the distributor shaft can be a problem. It won't give a significant level of performance but it will make the engine noticeably smoother

Thanx jimbro will look into a csc exhaust system i heard alot about it, thanx a million and im goin to opt for the other carbs like the dcnfs

Not sure how much use it will be to you specifically but the easiest source of DCNFs was to get them from an old (pre-EFI) MG Maestro. They were pretty much ready to go in an X1/9 and you just needed a suitable aircleaner and a manifold. I think these cars might be even rarer than X1/9s though, definitely so outside of the UK.

Many years ago I had a maintenance guide that listed all the models fitted with them but the book is long gone sadly and I've never been able to get another, new copies go for over £100 these days!

If you aren't afraid of spending some money you could just opt to use a set of weber compatible (such as Weber Alpha or Jenvey http://www.jenvey.co.uk/home/twin-t...style/jenvey-dynamics/tc-body-40mm-dcnf-tc40i) throttle bodies and switch to fuel injection. The downside is the need to replace your entire fuel system except for the fuel tank. On the upside it would solve your electronic ignition problem at the same time.

I have a set of ex-Hayabusa throttle bodies on my Seicento controlled by a DTA management system. The throttles were near-enough free, the rest of the hardware was a few £100 but the cost of getting it mapped was easily the biggest portion of the cost and it still isn't finished.

What do Alfa Romeos Sud, Sprint and 33s use as carburetors? Alfa boxers are still plentiful around here, particularly the 33.
Merry Christmas

Hi,
You might find some useful information in the last post i put on the TIPO thread. Im using The 1.3 fiat 128 engine for rallying which is a very similar almost identical engine to what you are using. and im keeping it very simple. No fuel injection or electronic ignition and i hope to get 125+bhp. You will pick up racing bits for these engines here : fiat128.de and simepowerfiat in croata.
scott

simepowerfiat have a bit of a clearance sale going on at the moment if you're interested.