Later 164 or 75 Fuel Rails

[Fylnn]

For various reasons I am looking to convert my GTV6 over to the later style o-ring injectors.  Mainly to work better with the Haltech it has.  I tried some adapters like in the photo, to use with the existing barbed fuel rails, but the whole thing ends up sitting a bit too high and problem comes with putting the plenum chamber back on.

The best solution seems to be to use a fuel rail designed for these o-ring injectors.  I believe that when the V6 went from L-jetronic to Motronic it would have gone to o-ring injectors.  Does anyone have a photo or knowledge of what the fuel rails looked like on later engines?  I realise the mounting are different and I would have to fabricate something, but curious if this is a starting point to achieve what I want to.

[Cool Jesus]

Hey Flynn, here's the rail for the 164. Its of a 12v 3.0L Motronic system, I believe the 24V is slightly different again. Best I could do for you at the moment. I could do some other photos if needed?

[Cool Jesus]

Found a couple of clearer photos on the net. I previously mentioned there may be a difference between 12v and 24 v, I may be mistaken with that. I now believe its the air tubes that change not the injectors

Anyhow a couple more pics. I was also thinking, rather than use the barbed adaptor, can't you just tube and hose clamp the o-ring injectors minus the adaptor? I've just added the barbed version for reference (I believe its a shiny_car product  )

[Fylnn]

Thanks Cool Jesus this is exactly what I was looking for.  The later style fuel rails would be the go assuming they fit.  Question then is will they or can they made to fit on the older engine?  The barb ones now wiggle there way through the inlet trumpets.  Then there is the issue of mounting the fuel rail securely to retain it and the injectors.

But it looks like something worth studying.  I will stick my head under a 164 bonnet at some point and do some measuring. 

[Cool Jesus]

What if you got your hands on a set of later rails. Cut the injector cups off. Cut the barbs off the old rail then braze the cups onto the old rails. Your injectors are retained by that collar already, and you could then use the clips up top to hold the rail onto the injector. Considering your rallying, you could move or fabricate the two legs on the rail to be held down at one if the collar screws that hold the injector in the head.

[jazig.k]

Have you thought about making your own fuel rails? Might be a bit easier for a machinist to knock up but no reason you couldn't do it at home.

Cut copy from here http://www.driftworks.com/forum/technical/71178-top-feed-injector-setup-infor-req-black-top-sr20det.html

"I've got a 3ft length of aluminium fuel rail extrusion on the shelves in the garage.. easy to tap the ends for fittings, you can even buy a machine bit to cut the injector seats for top feed injectors.





All you'd need to do is measure the spacings on the manifold and cut the rail accordingly, then mount it up somehow."

[Fylnn]

Cool Jesus, I need to lose the overall height which the adapters add to fit it under the plenum.  I already have the top feed o-ring injectors so they would go straight in to the 164 fuel rails assuming spacings and all the rest the same. 

Jazig.k, well yes that is the other option, have to do some measuring.  Thanks for the information.

[Cool Jesus]

Yeah I think I'm following you, my post mustn't have been understood. Using the old rail replace the barbs on it with the cups off a later rail. Don't use the adapter at all. I'm assuming , and it looks like the injectors are similar in height so your not adding height, in fact with the cups I believe you'll reduce its height by at least the length if that short hose? I'll see if I can draw up a mud map of what I mean

[Fylnn]

Cool Jesus, yes I see what you mean, I had it back the front.  You can buy the caps, might look into welding options. 

[Domenic]

Flynn....

To use the 164 setup, you would need the intake manifolds off a 164, which basically they bolt up to the heads, then the intake runners bolt to that. This manifold has the ports for the 164 style injectors and also a thread to screw down the injector rail to hold the injectors in place.

The only thing you would then need to do is fabricate new intake runners, as the GTV/75 style ones will not bolt on. Basically the GTV6/75 setup the runners bolt onto the head, whereas the 164 the manifold bolts to the head and then the runners bolt to the manifold.

The benefit though of doing a 164 setup is that you can make the intake runners bigger in dia instead of spending countless hours trying to port out the standard ones (as i have) to a bigger dia for a bit more ooomph.


Hope that info helps and makes sense