2.9 Fuel Injector Rail

[TMRnoV]

Hi All

On my 89 S2 the fuel injector rail is a pressed steel item, I would like to change it for the later cast alloy item that is sandwiched between the plenum and the inlet manifold, I have sourced a rail but I'm not sure what the thread is on the fuel inlet, a 3/8 BSP fitting does fit but so does an NPTF fitting.

The difference between the two is only 1 thread per inch and 3 hundredths of an inch in OD.

Would really like to use the correct fitting so does any one have a definitive answer (or a proper fitting as supplied by Mr Ford)

Tim

[phillpot]

TMRnoV said:

I have sourced a rail but I'm not sure what the thread is on the fuel inlet, a 3/8 BSP fitting does fit but so does an NPTF fitting.

Certainly not definative answer but I used BSPP fitting when I changed mine.

Did you get the different fuel pressure reg with the rail?

[TMRnoV]

Hmmm never heard of BSPP, what's the difference ?

Thanks for the reply

[TMRnoV]

Google, British Standard Parallel Pipe, Didn't know that existed, ah well you live and learn, thanks again Phillpot

[phillpot]

BSPT = tapered thread

[TMRnoV]

phillpot said:

BSPT = tapered thread

Yup, found that as well, and yes I did get the fuel regulator with the rail, just no fitting, having a search now.

Cheers

Tim

[sighck]

It's a different plenum as well, the plenum for the alloy fuel rail is lower (compensate for the different height of the fuel rails)

[TMRnoV]

sighck said:

It's a different plenum as well, the plenum for the alloy fuel rail is lower (compensate for the different height of the fuel rails)

Hi Hasse

Yes I was thinking about that when I decided to make the change, I decided (wrongly) that Ford would just use a longer bolt (would that work. I see no reason why not) luckily I bought the correct plenum (completely by accident) so that when I offered up the plenum, the fuel rail and the inlet manifold my original bolts are the correct length.

Just dumb luck on that one.

Tim

[phillpot]

A taller plenum could bring it very close to the bonnet ?

(depending on how much your engine mountings have sagged!)

[sighck]

Hi Tim,

It's not that simple just to use longer bolts, the distance from the valve up to the end of the neck has an impact on the performance. I'm not that good that I can say what will happen if you increase the distance with 10mm, I only know that it has an impact.

/Hasse