Corsa on carb fuelled

[johnny27]

Hi there, hope its okay to talk about corsa's here, as i will be using my nova eng and parts on it. I have a nova 1.2 C12NZ engine spare. Its got some mods done to it, ast2 cam, 1.2 carb worked head, webber 32/34 twin choke carb and 4 branch and so on. I found this little engine to by quite nippy along with my 4.18fd F10 box, anyhow i want to transfer all to my 1.2 corsa 8v, the only problem i can imagine would be at MOT time when i would need to refit the cat converter and get the carb tunned for the emmisions, can ne 1 else think of anything other problems i would run into when doing the conversion? I have experience with doing this same conversion to a spi nova, so i know about things like disconnecting the electeric fuel pump in the tank and that. I expect that i would have to use my nova carb igintion system also. Also whats the score on MOT day when they c a carbed car using a cat, will they have a prob with that? Any help appericated

[Riggy]

a carbed car cant use a cat

you wont need the cat if it passes the emissions test


wait for jack to come on and link you to the MOT testers manual lol

[Adam]

A c12nz wont pass emissions without a cat.
And cars with a carb dont run a cat, so if it has a carb fitted it can't pass emissions for cat rules.

[johnny27]

Thanks, so what option do i have, do i use the 12S block that runs with a carb and change the log book for the 12s nova engine. Or if i use the 12NZ with a carb, would i have to switch the fueling over to injection every MOT time, which is more has hassle than its worth. Any advice on what i should do?
Incase your wondering why i want to use a carbed corsa is that, i want to do away with the orginal SPi (no power) so my other tuned engine with a carb would be a big improvment (no rocket ship though) I can't put a 1.4MPi in because of insurance reasons and the 1.2 16v would'nt be worth the hassle. Cheers

[Adam]

If you use a c12nz block, then it will need to pass a CAT rules emissions test at MOT.
So you would need a cat fitted, which you cant do with a carb.

You could fit a 1200 carb block, with your weber etc top end, and that should pass MOT.

But tbh i wouldn't bother fitting a 1200 carb engine into a corsa, carbs aren't worth the hassle.

Just use a c12nz on standard spi(which is not crap) you could then fit a decent exhaust and manifold, and re-fit the cat for MOT.
Look at the technical guide at the top of this forum, that tells you how to get the most from your SPI engine.

You could maybe try the AST2 cam in the c12nz engine? I dont know what it would run like, but it should increase power.

[johnny27]

Was thinking about the AST2, but i imagine there would be little difference as i think the Spi would not give enough fuel for the lift, would i be rite in saying that? the ecu would need remapped 4 proper power, but i don't think you can chip or remap the c12nz ecu, what do you think

[Adam]

It should make a difference, as the increased lift would bring in more air, which the ecu would add more fuel.
It would certainly be better than the std 1.2spi cam, but i aint got a clue how the engine would run with that cam fitted.
You could just fit it and see what its like.

The cam should have both a pin type drive, and a slot drive. So it should work in any engine.

[johnny27]

Thanks guys 4 the advice. I imagine the ast2 on the spi would be very lump i think the cam is a 285, but maybe worth a try, is it possible to adjust the idle speed on the spi? as i imagine it would need to be set to tick over higher as the cam was wild lumpy even running with my setup 32/34 webber

[Adam]

No, you cant adjust the idle speed on a 12nz, as the ECU controls it.

[johnny27]

Thanks. Had a look on your white Nova specs, with the mods you've done on you 1.2i how does if feel compared to std? Do you change the cat bck for mot? Cheers
btw lovely nova real minter

[Adam]

Thanks. Had a look on your white Nova specs, with the mods you've done on you 1.2i how does if feel compared to std? Do you change the cat bck for mot? Cheers
btw lovely nova real minter
Mines a lot better than standard 1.2i, and should be around 60ish bhp now.
I haven't got my MOT till November this year, but i will have to swap my entire exhaust and manifold for my old exhaust for the MOT :roll: lol