Is an SR head the same as a L head?

[beavy69]

Is an SR head the same as a L head for a 1.3?

Which would be the best for porting etc?

[mikey14sr]

They're the same afaik.

[dan23]

yes mate same engine ( aslong its same cc eg 1.3L 1.3 sr same

[Adam]

1.4 SRi head is best for porting.
As its the best head to start with.

Perfect if you have a 1400 with t40s.

[beavy69]

It may be the best head to start with but I have been told that you will hit the water works much easier and the compression is rubbish compared to 1.2/3

[Adam]

What bottom end are you using? 1300?

[beavy69]

yep

[Stuart]

1400 sri head, skim it. wont need much in the way or porting either...

[Geth]

How can I identify if I have a head is 1.4SR or 1.4SRi?

[Stuart]

sr head has "square " inlet ports, sri head has round inlet ports and possibly an EGR hole inbetween 2 and 3

[beavy69]

can sri take carbs though, i though was just injection?

and are you sure that is better than a ported 1.3/2?

[Stuart]

with a 1.6gte/gsi inlet manifold you can fit T40's nicely...

its got bigger valves too so tahts a "freebee" in that case. benji gained 10bhpish by simply swapping a 1.4sr head for a 1.4sri head... now you might pay/spend loads of time for that or even less than that from a 1.3 head.

[Adam]

Only problem is everyone uses them now, so people pretty much charge what they want to sell one,Lol.

Probably best going to a scrappy and ripping one off a higher spec 1.4 mk3 astra(LS,Si etc)

[beavy69]

Would my 4 into 1 manifold fit a 1.4 Head?

Stu how do you fit t40s with a 1.6 manifold. Its just I have some Mikuni bike carbs. I was going to fit em with silicone hoses to a cut nova manifold and lip the steps of the tubes. But what do I do about the water? Could I just bypass the manifold or does it really need cooling?

[Stuart]

i ahve no idea WTF those carbs are. basically your into a "uniquie" project and because of that your having to work things out yourself ;) but im sure you could get a 1.4 mpi inlet, chop it down and do the same lipping to that


all small block 8V exhaust manifolds fit all the heads... its just the system matings that are different. (bar the 1.0 and 1.2 push rod engines)

[mikey14sr]

But what do I do about the water? Could I just bypass the manifold or does it really need cooling?

On a T40 manifold the coolant coming from the head just goes into a little box-shaped hole, a water hose goes from this straight to the heater matrix.

[Snowface]

Would my 4 into 1 manifold fit a 1.4 Head?



yes. exhaust ports are the same shape and in the same place on all nova OHC's.

[beavy69]

Thanks for your help everyone.

I was going to cut the pipes of a standard manifold (i've got a 1.4 spi knocking around, are mpi ones a bigger bore?) leaving the water channel undernieth intact. Then I was going to weld a 5mm thick alu plate and cut the holes in it to bold the carbs on that way. But thats alot of flukin about and I don't have a tig welder yet lol I guess I could leave a bit of the entering water channel poking out to pipe the water to the heater matrix like Mike said. But I can't remember where it normally goes after the manifold. then I could remove the rest of the water channel giving me room to attach silicone hoses for the carbs.

Stu, Mikuniks are apparently a popular grass track addition. Mine are a side draft bank of four 43mm carbs found on 1100cc Kawasaki bikes. I am currently playing email tennis with Mikuni distributors of Eng to determine a couple of things. Mainly will I need an electric fuel pump and if so what controls how much fuel it shoves in? (an air flow meter?)

[beavy69]

oh yeah forgot; will my 1.3 cam and housing go on a 1.4sri head with the normal bolts ok?

[mikey14sr]

yes, but you want to be using at least a 1.4 carb camshaft to make all the other work worth it.

[beavy69]

so I could just stick that bp 285 that you got in my cam housing and run it on the sri head?

[mikey14sr]

yep

[Adam]

what controls how much fuel it shoves in? (an air flow meter?)
Thats what a carb does, puts fuel into the air flow.

You could use an electric fuel pump with a pressure regulator to get it down to carb pressure.

[beavy69]

Yeah but carbs have their own resovior of fuel that is topped up by the fuel pump. In normal small engine novas like mine there is a mechanical pump powered, and thus flow rate mediated, by the speed of the engine. But with more fuel going in with bigger carbs I don't think a standard mechanical pump will supply enough will it?

In which case, as an electric pump is not driven and thus controlled by the engine, what determines how much fuel it needs to pump?

[mikey14sr]

I think it's the speed of the pump motor or a limiting valve built in to it, for example, a facet red top is regulated to 6-8psi, at a flow rate of 45us gallons per hour.

[Adam]

Yeah but carbs have their own resovior of fuel that is topped up by the fuel pump. In normal small engine novas like mine there is a mechanical pump powered, and thus flow rate mediated, by the speed of the engine. But with more fuel going in with bigger carbs I don't think a standard mechanical pump will supply enough will it?

In which case, as an electric pump is not driven and thus controlled by the engine, what determines how much fuel it needs to pump?
Ye, the electric pump supplies a constant amount, and the regulator then alters the amount to the engine as required.

A standard nova mechanical pump can run twin carbs fine afaik, using a pressure regulator.

[beavy69]

does anyone know how much I need to get the 1.4SRi head skimmed by if i'm putting it on a 1.3 block?

[beavy69]

So does the regulator just go on the hose between the pump and the carbs?

do they need a power sorce or are they simply a valve?

cheers

[Snowface]

the standard mechanical fuel pump found on Pierburg equipped Nova's is more than adequate for the job. in fact its too adequate at 6-8psi.

If your running Weber or Dellort then you need precisley 3.5 and 3psi respectivley. Much more than this and you will be flooding the float chambers and start washing the bore's (which ain't good).

Mpi and Spi pumps are waay to powerful. if your going for an electric pump then make sure its low pressure and is regulated to the amount stated above.

The mechanical pump in tandem with a regulator (e.g. fuel king) is absolutley fine though.

[beavy69]

Does it matter is I use an SRi head from a spi or mpi?

and if I used the SRi inlet manifold to fit carbs could I just plug the injector holes?

[Stuart]

the sri is ONLY mpi.. the spi head will be nearly the same as a 1.4 carb head anyway.

yes plug the inj holes.

[Adam]

If your having trouble finding a sri head, remember mk3 astra 1.4 cesaro, GLS etc had them fitted, as well as early Corsa SRi's.

Yep, the SPI is identical to the 1400Sr head, and is crap.

[beavy69]

crap compared to what a 2L? what would you put on a 1.3 block then? Wot do you mean?

[Stuart]

the 1400SR, 1200spi and 1400spi heads are really restrictive compared to the 1.2 carb, 1.3 carb and 1.4/1.6 mpi heads.

[beavy69]

Could I use a GTE head?

Would I need a 1.6 cam and housing?

Would my 4 into 1 manifold fit?

cheers for your persistence and patience lads!