My Port Injection Set Up

[SilverDemon]

This has been something I have wanted to do for quite a while now. I had to put it on hold until the intake manifold was on the market, I just couldn't take on 2 projects at the same time.

I talked to several techs (that are much more knowledgeable than I am about AUX fueling) about fuel injector options, fuel rails, hoses and sizes that would be able to handle the amount of fuel I need. The guys at Ballenger Motorsports ? High Performance Electronics were by far the most versed at setting this system up.

After talking to them for almost 45mins we decided that these were the best injectors to run. Home » Shop » Fuel » Injectors » Siemens DEKA IV ( DEKA 4 ) Mototron 60lb/hour High Impedance Injectors ( Short Style ) These are 60 lb 4 orifice 30° spray pattern high impedance injectors. 43mm in length, with an installed length of just under 24mm, this is a plus when installing in the tight confines of my engine bay.



Next, I went to Dash 6 Fuel Rail Extrusion - Ross Machine Racing for the fuel rail and bungs. These are high quality pieces, and best of all they are cheap, probably the cheapest part of the install. Now I have a blank fuel rail, I needed to cut o-ring ports for the injectors. The injectors are a standard domestic 14mm o-ring. For those of you that are into machining will appreciate how difficult it is to accurately cut an o-ring port. But never fail RmR has a beautiful tool already modified to cut a perfect o-ring port, It is pricey, but to me, worth every penny. 14mm Injector Port Tool

Now I have all the components to start modifying the intake manifold, by far the most nerve racking part of this install. I stopped by my buddy's machine shop since he has the proper fixtures to set this up properly. The angle of the injectors are 40°. We started off by cutting the bungs at the proper angle and length, which the length ended up being .620" on the short side at 40°.

The next step cooked my noodle for a minuet. The manifold was bolted to the table upside down and backwards. I struggled with what angle the table was to be set. At first, I thought this will be easy, I need a 40° on the injector, so the table has to be set at 40°. Wrong answer, it has to be set at the other half of 90°, so the table has to be set at 50°.

Next was to figure out where the long side of the bung would hit on the runner. I wanted to hold off the head plate .950" to give the most time to let the fuel atomize and also to hold the spray off of the divider in the head. Normally doing something like this on a 90° cut to the plane would be a simple calculation of the total of distance plus half the diameter of the cutter to achieve the center line. Well, when you throw an angle into the equation it gets a little more complicated. There are formulas to figure this out, but my cave man brain could not figure it out. So, I called my buddy over (knowing that I was in over my head) and asked him. He mentioned that there was more to this than a hard and fast calculation. He implemented some Kentucky windage, more to allow for tool flex on a longer cutter than anything.

We used a 1/2" end mill first just in case something was not right with his set up. He was able to hit it the very first time, sigh of relief!!





Next up was an undersized 3/4" end mill. The injector bungs actual measured .743".





Now I have a pocket in the runner to help orient the bungs for welding. Fits like a glove!!







I was still worried about keeping everything lined up with the heat from the welding process. I was not going to put the injectors in the rail and in the bung while I had the bungs tacked welded in place. Too much heat for my liking. I made some dummy injectors.



Fuel rail was next. Pretty much self explanatory.





Mock up of the dummy injectors. The rail looks a little crooked because they are just sitting in place and the bung slipped into the pocket.





Mocked up in the car with injectors. I need to trim the rail down about .750" on each end, that is the least of my worries after cutting holes in a perfectly good manifold.