EFI Intake Experiences

[Leviathan]

Hi all,

Wondering if anyone has tried to have the intake cut and the injectors welded in at a local shop, assuming of course I provided a set of drawings and technical requirements for where to drill and weld the injector bosses. I have seen this done on an Olds 455, but locally in a home garage.

I was looking at Force-EFI but the cost is way up there when I convert to US dollars, I need a Canadian shop I'm afraid...

...any advice?

[bobc455]

If you're going to try to save some $$ by machining it yourself, don't forget that you will still have to buy several items that are included in their price:

- Fuel Pump
- Injectors
- Bungs
- Fuel rails
- Fuel regulator
- Throttle Body

I think you'll find that the machining is only a small part of the cost. Even if you could save $100 by having someone local machine it, the extra $100 might very well be worth it because of:

- System Engineering
- Experience
- Tuning assistance after the installation

Just my $0.02.

I think Kerry S. did the work to his own manifold, maybe he can give some insight.

-Bob Cunningham
bobc@gnttype.org

[KendallF]

I did my own; there are pictures of it at the link in my signature. If you've got access to a good drill press and someone who can TIG weld, it's not too bad. You can get the bungs & rail stock from PT&E, Kinsler, and others.

I visually aligned the bungs to the center of the ports, then scribed the parallel line to locate the plane that lines them up. I drilled the holes in a drill press, using a bit sized so that the bungs just slipped in. I did mine vertically; if you want to lean them over in either plane to target the ports better you'll require some sort of jig to align everything.

I scratched my head for a while wondering how to hold the bungs for welding..I ended up marking the fuel rail, drilling it for the injectors, and inserting scrap injectors into the rail and bungs. I then clamped this whole mess down and proceeded to weld the bungs. Even with this method, I ended up with a couple that were slightly off and since I had access to a mill, I milled the tops to even them up.

Since I did mine, I saw somebody else's site where they made wooden dowels sized to press into the bungs, then made a wooden rail on both sides and cross pieces that bolted to the carb flange. I like that idea and it'd probably work better with less fuss.

After you've got the bungs in and the rail drilled, you need to fabricate rail hold downs; I made 2 small diagonals per side that are tapped for a bolt through the bottom of the rail and welded them to the front and rear runner.

For a throttle body, you have several options: I'm building a twin turbo S2 V6 so I went with an elbow PT&E sells that allows mounting a 90mm Ford TB. This is convenient for me since it's round and aimed toward the front. You can buy a 4 bbl throttle body. The cheapest thing would be to use a 4 bbl carb baseplate, and put a carb spacer on top of it for a smooth entrance to the baseplate. I saw this in a lowbuck EFI article in some (gasp) Mopar mag. :)

Good luck whatever you decide...I had fun doing mine.

[Leviathan]

...as it turns out Force is quite willing to supply the compoentns and let you machine/weld everything yourself! That's about a $1200 savings from my point of view. Besides, I'd rather have all the fun making it.

Kendall, had a look over your site, thanks for the tips! What did you do for weling up the injector bosses?

[GSXMEN]

I like the suggestion about making wooden dowels to help mock up the bosses to hold while welding! Sounds like a clever idea.:TU: