Canada1

What is required to machine the MFI injector boss on the MFI injector rail to accept a Bosch EV1 type injector?

I have the MFI xr3i fuel injector rail (bolts between head and mfi intake manifold)

I am sure this modification has been done to use an mfi intake for efi conversion.
How deep do I machine for efi injectors? Anyone have a picture of a modifies mfi injector rail?

I want to build a custom intake manifold using this fuel rail. I will weld on new
manifold tubing and a custom plenum.

Hope someone can chime in.

Cheers

Daveysaff

iTrader: (9)

I've just done my MFi sandwich plate to take Bosch 83's so I can run an MFi XR3i inlet?
Took the MFi injector holes out to 13mm and the injectors sit in nicely, just have to file a little off the runners to get them to stay in!
I'm using an EFi Fuel rail too, but with the locating tabs moved round and lugs welded onto the runners.


just re-read that and it sounds confusing I'll put a pic up eh?

nigel b

the injector holes need to be 14mm with i think a 15 degree lead on the bottom
be careful doing it as it is a compound angle
its not hard to do if you can use a mill and have access to a adjustable angle plate

XR2

Just check out my thread, there are some pictures of the sandwich plate. I use the MFI plate, RS1600i inlet and an XR3i EFI rail.

A friend of mine drilled the holes to fit the injectors for me, so don't ask me questions about how to drill them

Canada1

Thank you all!
I think I know what to do to fit efi injectors.

I looked through your thread XR2, fantastic car build.
I love those RSi valve covers. I want one.

muz

I drilled mine out myself and had no problems. I drilled them in stages to fit the shape of the injector making sure the 'O' ring sealed well then had some tabs weled on to hold the fuel rail. I can't remember the sizes though.













The one thing I did notice though is the alloy they are made out of is very poor. My new manifold has steel injector 'sleeves' made which are pressed into the sandwich plate, which I don't have pictures of at the moment.

DazC

iTrader: (1)

Muz,

Those fuel rail brackets WILL crack off when you start using the car due to vibrations. I've used that method before and had the thin ally brackets break leaving your fuel rail to float around and pop off the injectors dumping fuel everywhere. You'll need something like 4mm ally and get it welded on properly. I advise STRONGLY that you get them changed.

I bought a 10mm/13mm step drill and then reamed them out to 13.8mm on my manifold. The step drill has a 10mm drill stepping up to 13mm so it acts as a guide to keep the drill central. Then the ream takes out the rest of the material whilst ensuring the holes remain circular and smooth to get a good seal.

muz

Thanks for the info, Daz. I don't use this manifold anymore. I'm using Christians XR3i item.

Rob_DOHC

iTrader: (4)

I would love to use this method, and my mfi manifold, unfortunately i don't think i can now with my efi head

BUT

If you look how far mfi injectors protrude into the ports and what ford did to mount the efi injector the differences between them and the above is massive.

Slightly worried about how much fuel you will actually get into the 'air stream' rather than dripping down the port,

Rob,

Canada1

Hello Rob,

I don't think the efi injectors will have a problem spraying fuel at the back of the inlet valve.
Take a look at the spray pattern at 3 or 4 bar fuel pressure from the Bosch injector.
The sprat pattern is quite narrow at 10 to 15 degrees.

Rob_DOHC

iTrader: (4)

Ah cool, all good then. Don't think it would be okay with a wider pattern. Why do you think ford went to such lengths with the injector location?

Also Perry have you ever looked at a SPI 2000 cvh head? looks to have some potential!

Rob,