Some questions heads/cam/manifold

[SuperNova!]

Hi guys after getting just overtaken by a MG zr120 I want to carry out the following mods to make sure I never get overtaken by one again but have a few questions:

If I fit a 14sri head and fabricate the manifold for a single carb into fitting will I see much gains and is it easy to do?

Also I will be putting a fast road cam in the sri head while its apart but will the sri head accept a cam to run a manual fuel pump if not what head is better than the 16sv one?

What is rough estimate in power gains with a weber 32/34 tuned in, sri head, and fast road cam?

Thanks

:thumb:

[Adam]

Cam lives in the cam housing, not the head. ;)
So just fit your 16sv cam housing to the new head.

Think you would be better with a GTE/GSI head, as its a 1600 engine.
Probably see 15 ish bhp with a round port head, cam, and weber 32/34.

For the inlet, you would have to modify the ports on a 1300SR inlet, using chemical metal, sanded/filed until it matches the round inlet ports the of the head.

[alistairolsen]

use a standard sri head, and then get a cam and cam box with mech fuel pump from an sr (14nv engine) this is the most aggressive camshaft in the range.

For an inlet you will struggle as vauxhall never made one, so My solution was to get one off a 1.3 sr with cathedral shaped ports and fill the widened bottom of th tracts with chemical metal so the inlet tract was round all the way thu., thenmatch the ports to the head.

I chose to run spi rather than a carb, so i have and adaptor plate, then an 1800 cav throttle body, 1400 injector and ecu.

I made 82bhp on the rr last week, up from a std power of 60. That was with the cam timing out by a notch and fuelling with an afr of beyond 9:1 (the guage on the rr went no further). it feels aLOT more perky now, pretty close to 90 IMO.

EDIT: must type faster, or stop telling Ad how to do things :-P

[SuperNova!]

I was going to use the 14sri cam housing while I was at it because when I got my head skimmed 2 weeks ago I got new headbolts and they were the female star bolt thingys well, if you get offered them refuse they dont spead the pressure of the headbolt enough over the cam housing and they dont have washers, because they are too thin at the top one has cracked my cam housing at one end, luckily for me it isnt leaking at the moment!

Cheers matey but does anyone know anything about the manifold fabrication?

Thanks

:thumb:

[alistairolsen]

dont bother making one, theres no point, and youre meant to reuse the washers, if youve fitted them without I suspect they will be hard against the bottom of the hole destroying your block, but hey ho

[SuperNova!]

I am going to get a manifold to play with then, All because of that stupid mg!!!! :mad:


lol

[SuperNova!]

I didnt have any washers on my thicker headbolts and its been going for ages! lol lol lol

[alistairolsen]

manifolds easy. its got round tubes and about 2 inches from the end the floor drops and opens out to a square bottom edge. Just grind this so its rough and fill it up with chemical metal so its the same size round hole all the way thru. Use a dies grinder to finish it off.

[valverguy]

Mg 120 zr is not going to be passable without conciderable work assuming your car is an SR?

[SuperNova!]

They have 115 bhp and weigh 1030kgs,

He only just about done me I have 1600sv engine with some slight mods, rolling road tuned to run on optimax, 4 branch manifold and full system, k&n,

When I was on the rolling road it made 96bhp and 106ft/lbs torque while the engine was burning 3 litres of oil per tank of petrol before I rebuilt it,

I think with some more mods ill have a very good chance
:thumb:

[SuperNova!]

alistairolsen, thanks for the manifold help mate I know where to start now :thumb: