"spi sucks fit a carb"

[Adam]

Looking good.
Does that astra 1600inlet mate straight up with the 1200head?
And does the cav TB just have the same sensors as the 1200, the TPS etc all work fine on the 1200 ECU?

Be interesting if something similar could be done on the 1400spi astra engine.

[Aragorn]

yep all this can be applied to astra engine as the 1400 shares nearly all its parts with the 1200

the 1600spi inlet mates streight upto the head with no problems

ive got a 1400spi im rebuilding for my GF's astra and a few of these mods will be being applied to that also, i wont be decatting it to start with as its an L-Plate and needs and MOT but ive got an SR cam and im gonna get the 1.8tb and 1.6inlet for that too

after that a 1.6mpi manifold and downpipe, decat bypass thingy and perhaps a aftermarket exhaust system

[getlost29]

have u tryd to see if any of the spi manifolds will line up with the 1.2 carbed head, or have u though about using the sri head and 1.6 or 1.8 spi manifolds if they line up

[Aragorn]

i have

spi manifolds are miles away from both the carbed and mpi heads ports are higher and off to one side

with the spi manifold bolted to a carb head u'd prolly be able to put your finger in the port

im gonna look at making an adaptor flange for a carb manifold and maybe even mod it to fit a mpi head although that involves adding metal to the carb manifold i recon the bigger valves on the mpi heads will help things

the other option is a 1.6spi head, it has the same 38mm inlet and 31mm exhuast valves as the mpi heads but obviously has the square ports, i dunno wether the larger valves and sqare ports will be better than the 1.2 valves and better ports

anyone know which causes more of a restriction?

[Adam]

yep all this can be applied to astra engine as the 1400 shares nearly all its parts with the 1200

the 1600spi inlet mates streight upto the head with no problems

ive got a 1400spi im rebuilding for my GF's astra and a few of these mods will be being applied to that also, i wont be decatting it to start with as its an L-Plate and needs and MOT but ive got an SR cam and im gonna get the 1.8tb and 1.6inlet for that too

after that a 1.6mpi manifold and downpipe, decat bypass thingy and perhaps a aftermarket exhaust system

Be interesting to see what improvements there is then.
Does the Sr cam fit into the cam carrier, as its got the extra lobe for the mechanical fuel pump.

If i keep mine long enough, and there is a performance improvement, may try them mods on my 1400spi, its on a Jplate, so Cat and MOT is no problem for mine.
The thing letting down the 1400spi is the shit cam, and crap head, just like the 1200spi.

Does the 1.6mpi manifold/downpipe have a larger bore size than the 1400spi one?

[Aragorn]

its a 4-2-1 design like the nova sr instead of the 4-1 u have now so should flow a bit better

the nova 1.4sr made 72hp and the 1400spi made 60hp, with the sr cam and no cat u should be approaching the 72hp again

as for the head, 1.3 and 1.4 sr only had 2hp between them

the 100cc capacity increase should have given a 6hp increase so that shows the restrictiveness

[Adam]

its a 4-2-1 design like the nova sr instead of the 4-1 u have now so should flow a bit better

the nova 1.4sr made 72hp and the 1400spi made 60hp, with the sr cam and no cat u should be approaching the 72hp again

as for the head, 1.3 and 1.4 sr only had 2hp between them

the 100cc capacity increase should have given a 6hp increase so that shows the restrictiveness

Ahhh.
So the Sr cam fits fine inside the spi cam carrier?

[Aragorn]

yup mines installed in a nova GTE carrier but they are identical to the spi one

[Adam]

yup mines installed in a nova GTE carrier but they are identical to the spi one

Cool.
Looks like i am heading to a scrappy then.

:+: