SRi head on an NV/NZ block

[Aragorn]

ok ive had a little discussion with the boy over at mig about this and dont seem to be getting anywhere

i want to fit a GTE injection system to my C14NZ engine

at first i was gonna use a 1200/1300 head and hope this would do the trick but the folks over at mig dont seem to think it will

some reccomend an SRi head but they dont know how it will affect compression, the GTE head drops it and some say the SRi head is identical to the GTE - but then wouldnt the SRi be running 8.5:1 compression?

so basically i wanna know

1) most importantly will the port mismatch between the 1300 head and the 1600 inlet cause and major issues

2) will an SRi head fit a SR/SPi block without majorly altering the compression ratio

[Aragorn]

http://www.migweb.co.uk/forums/showthread.php?s=&threadid=60802

thats the MiG post

[mikeoxford]

1) most importantly will the port mismatch between the 1300 head and the 1600 inlet cause and major issues

AFAIK ANY port mismatch is bad and will hinder performance.........

[mikeoxford]

2) will an SRi head fit a SR/SPi block without majorly altering the compression ratio

which Sri head are you planning to use????????? it depends on engine capacity i would of thought TBO what the dome shapes in the heads are like........... :?: :?

[Aragorn]

ive calculated it all out and it seems the SRi head HAS to be different since to get the same compression ratio u need a smaller area in side the head for the 1400

ive also calculated that skimming 0.35mm or 15thou off a GTE head should give approx the same compression ratio as the SRi head does

and if all goes well - i'll get the GTE head and inlet off a friend :P and get it skimmed down :D

[Ben (lurk75)]

my heads still spinning from when we were chatting earlier!

[MC]

If you put a 1.4 SRi head on any 1.4 block, it will basically be a 1.4 SRi. ALl of them have the same block. The 1.4sri has a smaller chamber in the head to bring the compression up to 10:1.

Be careful when using a 1.6 setup. Don't think its as straight forward as you think. At least you know the 1.4sri ECU is setup for that capacity.

The 1.3 head will deffo be different. You'll get away with it as the head side is bigger than the manifold side, but its not ideal.

MC

[rgv_stu]

what about pistons?

i thought they were different on the mpi lump ??

the nv pistons have quite a big bowl in them. which if they were flatter like the 1200 pistons compression would be up.

what are the 1600 pistons like??

[MC]

It's negligable.

CP is running a 16V head on an old NZ (1.4SR) bottom end. He has had some skimming, but compression is about 11:1. I'd say it ran 10:1 before skimming.

MC

[Aragorn]

well my idea is to get the whole top end off a GTE and run that

ive been told i need to tweak the AFM and possibly fuel pressure to sort the fuelling

the GTE head will need about 0.35mm or 15thou skimmed off it to bring the compression up from 8.8 to about 10

what u think?

will i need to change anything else?? will it run with the original fuel pump and lines?

[locky]

I'd say the lines would be ok!
It may be worth changing the pump, coz the demand for fuel will be increased, but it runs off the impulses, so, the standard pump you have shouldnt be a prob UNLESS it pumps out at a higher pressure then it'd be worth changing!
Just out of theory that is!

[blaiz]

ooo, im interestd coz iv gota 1.4i (singlepoint) and woz avin similar thoughts..!

is it realy that simple, i cud just swap my head 4 a SRi multipoint injected head and all wud b gd??

is that the only difrence between them , just the heads??

wud i also av 2 change the ECU+ distributer??

ne fin else??

cheerz!

[Aragorn]

as i said up there u'd need the whole top end from a GTE

ie: Head (which would need skimmed by 15thou), cam box and cam, dizzy, inlet manifold with injectors, ECU and wiring loom

u could use an SRi head instead but u'd still need everything else from the GTE and the only advantage would be that u wouldnt need to get it skimmed as much

u'd then need to tweak the AFM spring rate which i assume fools the ECU into thinking there is less air flowing and hence delivers less fuel so the 1400 doesnt over fuel

add to this an SR or GTE ehxaust manifold, downpipe and center section and you should be sorted

u'd have an engine thats putting out at least SRi power if not more and if your lucky u could get the parts cheap

ie find a nackered GTE lump and whup the top end off it as long as the top end is all in good condition

[Ben (lurk75)]

ie find a nackered GTE lump and whup the top end off it as long as the top end is all in good condition

good condi*ion lump for ?100 eas*

[MC]

Why do you need the GTE stuff, the SRi stuff is equally as good.

If you get the sri head, it won't need skimming at all.



If you are interested, I have an entire GTE top end, head the lot. The inlet manifold has been polished too.

MC

[Aragorn]

i need/want the GTE stuff because its easier to connect up (no integrated wiring loom) and seems to be more readily available than the SRi stuff

the head will need a light skim anyway to ensure its flat so its not gonna take much more for the shop to take it down by 0.35mm

how much are u wanting for the top end?

i assume u have all the loom and ECU with all the sensors too??

[MC]

Between CP and I, I'm pretty sure we have it all.

MC

[MC]

Make me an offer.

[Aragorn]

i sent ya a pm