MSefi.com read only forum (Jan.15,2018)

I have read where pipe bushings where drilled out to make threaded injector bungs. I am in the process of converting a few to see how they work out. In the instructions that I found they said to drill through the bushing with a 1/2 inch drill and then slightly counter bore 17/32" to a .545-.550 depth. I have been having trouble getting the counter bore to center properly for I do not have a lathe. In looking at it, I was wondering if you need a counter bore? Was wondering if I could just drill the bushing through with the 17/32" drill. I see where some are saying to use 1/2" DOM tubing for injector bungs which obviously would not be stepped. I am using a cast iron bushing and was also wondering if a brass bushing would work as well. It would be a little better to drill through and they are easier to come by.

Well Just was wondering if someone in the know could let me know. Thanks, ghcoe.

5/8" compression fittings fit perfectly. They compress around the injector body. Just another low energy option....

-Mike

I believe the .545-.550 depth. is so that the injector does not project too far into the intake. If this is not a problem for you then go for it. Be sure your injector can bottom out a little higher on the body if you drill through with at 17/32 drill. You can use brass as long as you can attach, (braze, solder, or glue), it it to the intake manifold, but be VERY careful as brass is not very easy to drill without it "yanking". IMHO, stick with steel or cast iron as it is much safer to drill. MCMaster-Carr has all you could ask for and will ship to your door.
I don't know how you could use 1/2 DOM tubing as 1/2, (.500), is the outside diameter and you are using an o-ring that goes into a 17/32 (.53125), diameter hole. 1/2 in. pipe, however has an inside diameter of 1/2 and could be drilled to 17/32.

Thanks for the information guys. This is just the beginning of a project. I am sure I will have more questions as I go along..... George.