EFI, Alpha-N vs Speed Density fueling Strategies

[Signman]

Have heard of and read a few articles on this.
Injecting fuel behind the valve may not be the best location for atomization and mixture. Moving injector up the intake runner may allow better fuel distribution in the air stream. Pointing the injector into the air stream would seem to force the issue.
Some high HP engines have two sets of injectors: at the valve and up in the runner.
Has anyone played with direct injection in a HP application?
Sounds like fun.

[Tony Curcio]

Direct injection is being used this year by the Chevrolet factory teams at LeMans in their GT-1 Corvettes. There is a detailed story about it Engine Technology magazine, a British publication. If anyone's interested, PM me and I'll look for the back issue.

Also, USAC midgets use 4cyl engines with a 23 degree SBC head. They use a nozzle in the intake manifold, and drill a hole from the exhaust side of the head, into the intake port pocket, and call it a "down-nozzle". Every GM powered car in the class seems to do this. Kinzler does the drilling, and provides the the injection system, which looks like old mechanical Hilborns, but are fairly sophisticated electronic controlled units.

[Ed Wright]

I had a sprint car during the 1980s . We all ran down nozzles then. That has been around forever. Was still mechanical back then.
The big deal, we thought, was getting all that methanol out of the intake and port runners, making room for more air. Takes roughly twice the methanol as gasoline, which = less air. The nozzles were aimed to shoot fuel past/under the intake valve when open. Thing about those older mechanical systems, there was no injector pulsing, as with EFI. Constant stream of fuel meant an intake bowl full of fuel when the valve did open.
Brodix, AFR, etc, sold/sell their heads drilled for down nozzles.