1.2 engine tuning

[Cle]

Right i have a 1.2 block in me shed so thinking about building it back up for something to do, now before anyone says get a bigger engine im building this block up not any other, so im thinking maybe rebore engine to maybe a 1350 now i can get this done cheap as i use to work in and engine rebuilding place, then putting a 1.3 crank in it getting it reground, im mainly wondering what head is best to put on this ie 1.6 or 1.4sri etc ? so i can get the head then start fafing with it it'll be getting skimmed then ill port and polish it with new valves and maybe email kent cams and purchase fancy springs and lifters, then lariy cam, Also im planning keeping it injection so will it be better to add a 1.6 inlet and throttle bodie aswell ?

Cheers
Cle

[vaughanmc]

1400 SRi head is the one you want I think...With the big valves etc :)

Surely you'll be putting it multi point ?

[Cle]

If its and sri head which is best then ill need to mpi it then as the ports for a spi inlet will be different to a mpi inlet

[vaughanmc]

Ahh right :) I've been told the SRi head is the one to go for like

After that...I'm lost lol

[Damo]

Ahh right :) I've been told the SRi head is the one to go for like

After that...I'm lost lol

Correct the sri head has bigger valves as standard and has round inlet ports too.

[Cle]

so could i use the sri head and keep it spi ??

[Damo]

You could cle but you'll have to shape the spi's inlet ports to match the mpi head check out adams wip he did this and saw good gains too

[Cle]

hmm so maybe best to just go with the mpi then, then that opens new doors ie maybe custom inlet ? with sri injectors and bigger throttle bodie ?

[Damo]

hmm so maybe best to just go with the mpi then, then that opens new doors ie maybe custom inlet ? with sri injectors and bigger throttle bodie ?

Mpi is the way forward mate dead easy to wire up and bigger hp gains if your going for power the 1.6mpi throttle body has a larger inlet bore but the injectors from the 1.4 will be fine the standard inlet is also very good just concentrate on the headwork port polish etc......

[Cle]

Is the 1.6 ie gte or gsi throttle bodie bigger than the 1.4sri one ?

[Damo]

Is the 1.6 ie gte or gsi throttle bodie bigger than the 1.4sri one ?

It the c16se one cle thats the bigger one mate.

[TeddyThom]

I have a 1.2... Got some good ideas here, just to chuck in some of my own, would a 1300 cam shaft and a 1400 head be alright to use? Would I need the 1400 pistons etc?? Just want to make sure before buying it and making a complete fool out of myself lol

[Damo]

I have a 1.2... Got some good ideas here, just to chuck in some of my own, would a 1300 cam shaft and a 1400 head be alright to use? Would I need the 1400 pistons etc?? Just want to make sure before buying it and making a complete fool out of myself lol

Everything will fit mate but i would have thought it will be low on compression the 1.4 pistons will fit but ud have to get the block bored out easier to just stick a 1.4 straight in.

[TeddyThom]

Everything will fit mate but i would have thought it will be low on compression the 1.4 pistons will fit but ud have to get the block bored out easier to just stick a 1.4 straight in.

Sorry for the hijack Cle lol

So without boring out the block, what pistons etc would you recommend?

[mowgli]

you have to bore the block to fit anything other than std pistons.

[TeddyThom]

you have to bore the block to fit anything other than std pistons.

Standard as in 1200 pistons?? But won't I get piston slap with a 1400 head and 1200 pistons??

[Damo]

Standard as in 1200 pistons?? But won't I get piston slap with a 1400 head and 1200 pistons??

No because your making the combustion chamber bigger thus giving a lower compression ratio.

[TeddyThom]

No because your making the combustion chamber bigger thus giving a lower compression ratio.

So nice for turbo conversion. lol. That will be a long while away... Ah well cheers guys appreciated :thumb:

[mowgli]

Standard as in 1200 pistons?? But won't I get piston slap with a 1400 head and 1200 pistons??

piston slap happens in the sides of the bores when they are worn....

the stock pistons don't protrude above the block face, so they won't hit the head. but a 1400 head has a larger chamber than a 1200 carb head, so it would lower compression.

and attempt at increasing cc of an engine either by boring or stroking, will need work on the bores, cos if you increase the stroke, the original wear patterns & coking on the bores will be of less of a stroke than the new stroke, so the first turnover will damage the rings.