has any one ran a 1.2 carb on spi before

[stafford]

hi my aim is to build a fast 1.2 so i decided to us the short stroke type

up to now i got,

1.2 carb head ported,
1.3 inlet ported with a plate for an spi throtal body
spi throtal body with 1.4 spi injector
piper 270 profile cam

any idea's

[Nobby]

why bother put a 1.4 in it will be faster lol

[stafford]

i know but another thing is to prove some one wrong to. ive done a good few engine changes and builds some have worked some havent rangeing from the 1.2 to the 3.0 v6 in corsas and novas, if i wanted to go fast i'd jump in my corsa x30xe, but my usual drive arounds engine is nearly dead so il do this to save money to while im building my let for it.

[Sloth]

pointless, carb is better.

[stafford]

sorry, i never said reliability is an issue to, i did it years ago, a 1.3 sr carb on a 1.3 inlet 1.2i bottom end and 1.2 carb head, it was fast but, i want the spi.

[djbrowney]

a the port shape is differnt between inlet and the heads iirc

[stafford]

the 1.2 carb are cathedral and the 1.3 inlet is cathedral there matching

[Sloth]

the spi is crap, the carb is better in all respects

[bmw156]

lol why waste your money....

[Adam]

the spi is crap, the carb is better in all respects Pmsl
Is it bollox :thumb:


The Spi makes 45hp, carb makes 55hp

BUT the spi has most restrictive/mild cam EVER, most restrictive head and inlet ever, a CAT, and the tiniest throttle body ever lol lol
Binning the cat and fitting a standard gte cam gives you your 10bhp back. Oh and it'll start in the morning and run on its own without dicking about with a 1960's choke ;)

1.4spi and 1.4SR exactly the same. SPi has to55 cam, cat, same size tb as a 1.2!, and a single downpipe. 1.4SR makes about 10brake more with the "biggest" nova cam, a twin choke carb and twin downpipe exhaust.....

The engines are pretty much identical tbh it terms of performance when its a fair comparison.

Oh and my old 1.4spi made 86bhp on the rollers iirc, only held back from making more due to the low rev limit Spi engines have :)

[AlexW]

SPi is more reliable.

I presume the question is what else can you do? Exhaust, air filter.

[jimbob-mcgrew]

your probably set on the spi by now, but i wanted to say.. as youve allready got the 1.3 inlet, why not go for a twin choke 32/34 weber carb, it'll out perform prety much anything u can put on there bar twin carbs. might cost about £75 tho depending on your finaces. a 4-2-1 sr exhaust will accompany it nicely too :thumb: