heads

[James B]

two question, im just thinking through some possibilities

Will inlet manifold, head etc off a 1.4SR work with a 1.4SRi straight on, with no probs? cant see why it wouldnt but thought id ask to make sure

also will a 1.4 head fit on a 1.2 block, i think it looks like it will in terms of the outer casing but what about the valves clearing the pistons??

Any help would be greatly appreciated
:lol:
James

[Stuart]

the 1.4 head has square ports and the 1.4 sri head has round ones (as far as i remember)

also the 1.2 - 1.4 have the same sized valves jsut the inlet port shape is different. if you were to fit any head to your engine it should be a 1.6 gte/GSI one, failing that a 1.2 head as youd gain a few decimals on you compression ratio and thats a good thing too

[nova_rally]

How do you guys work out that there's an increased compression ratio? The specs for both engines give the same compression ratio. The only way it would be increased is if you 'fill in' some of the clear space above the piston, so unless the bottom of the head is substantially different then I dont think it will make any difference!

The 1.2 Head (and 1.3 head) have a better port design than the 1.4SR head, so that would indeed improve performance.

(My 1.4SR is now extremely quick wiith just a PEco BB2 and an Astra 1.3 (13S engine) head.)

Alan

[j1400]

CR is the chamber volume divided by the piston/bore displacement plus chamber volmue.
So the chamber volume gets small as the cc of the piston/bre deceases, like this.
Assume CR to be 10:1
1300cc engine. so 1/10= cv/(cv+325cc)
so 10cv = cv + 325cc, 9cv = 325cc so cv = 36.1
1600engine. 1/10 = cv/(cv+400)
cv = 400/9 = 44.4

If I f**k'd up my maths there let me know, but that's why.simple was to get CV is bore cc/ CR-1.

[Snowface]

i think londoner is asking if the 1.4sr head/manifold will fit on the 1.4sri block.

[j1400]

How do you guys work out that there's an increased compression ratio? Alan

Just answering the Q

[James B]

what exactly u mean the ports are different sizes, does this mean that the 1.4SR head WILL NOT WORK with the 1.4 sri bottom end? If this is the case - D'OH!! Proper butt fucking

that dont really leave me in a good position, i take it then that similarly u cant just bolt the pierburg carb onto the 1.4SRi head? only OTHER option is to get the whole sri engine and wire in the loom for the ECU, i do NOT like the sound of that in the slightest as i was anticipating getting the whoel engine transplant from 1.2 up to 1.4 in a weekend. I have found a rebuilt bottom end you see from sri and have a head off sr lurking around and if life was simple it would've been gravy. however, life sucks

I spose i could hang out for a 1.4 sr bottom end rebuilt but i dunno if i can wait that long, my engine is gonna go caput any day soon done bout 130k :(

any other help would be greatly appreciated, as i am now at a lost cause!!!

James

[Aragorn]

if your running it on carbs the 14NV head will fit the sri block fine since your using the original 14nv inletmanifold

the better option would be to aquire a 1300/1200 carb cylinder head and fit that onto your sri block

1200 might cause detonation issues cos the sri already has higher compression than the sr

so to be safe i'd suggest a 1300 carb head and a 1300 inlet manifold and bolt your pierburg onto that :)

[j1400]

Yes it will fit, but the port shapes won't match. you'r better off using a 1.3SR manifold for the carb to mount to.

[Euan]

i havea 1.3sr head, needs skimmed but only done 64,000 miles??

[rgv_stu]

as far as im aware the sri block is the same as the sr block. the pistons etc look identical from what ive seen (i had an astra mpi c14se and a 14nv next to each other comparing). i would guess the sri increased comression is either smaller head chamber or thinner head gasket.

my 2p

[Aragorn]

SRi (c14se) pistons are listed differently on the epc from the SR/SPi (14nv/c14nz) blocks which are identical

u will be able to fit your 1400 head and your carb inlet manifold to the sri block just fine

[rgv_stu]

fairy muff
well if you get the chance to compare the 2 you will see what i mean aragorn

[nova_rally]

1.4SR head (with the 1.4SR manifold) would fit fine on your 1.4SRI botttom end. You might have trouble fitting the 1.4SR Manifold to the 1.4SRI head if thats what you intend to do.

I would reccomend a 1.3 head though - my 1.4SR is now very fast! (before it was very slow)

Alan

[Snowface]

if u wanted to MPi a 1300sr would all u have to do is put the 1400 sri head on the 1300 block + loom, zorst etc. Perhaps skim the head and blok first to gain back CR. What sorta performance u looking at. 75bhp?

[nova_rally]

Plus the EFI Fuel Punp (so probably the whole fuel tank).

Alan