NA Mechanical Fuel Injection

[LZ]

Hi:
Submitted for your approval, Said in your best Rod Serling voice.

There is lots to think about , but one thing I have a query on is , Nozzle Placement.
 I realize its a loaded question with the motor combo, RPM, Gearing etc. Hypothetically, Given all things else being equal  . Do you think there can be a gain - loss to where you place the nozzle.   Do you give consideration to the tuneup with regards to this?
 Was under a simplistic interpretation its best to get nozzle as close as possible to valve.
Case in point my own set up. Enderle stack (early Hemi) and the nozzles are put prit close to the butterflies. You could move the nozzles downstream a few inches easy.
Along these same lines the butterflies vary as to there distance from the valve. Any thought there? IE how some of the A Fuelers are set up with these newer fuel injectors.
Remember seeing a car a few years ago (Think at Bowling Green?) Where they had made plates for in between Head and Injector. They had placed the Nozzles in the plate. Was a simple Alcohol NA dragster.
Just thinking, always good to hear what peoples experiences and thoughts are.

thanks Spud for all your help on here.
Luke

[Spud Miller]

 The denser/wetter the air/fuel ratio, the more of a benefit it is to put the nozzles as close to the cylinder as possible.

 On gas setups (very dry AFR), many times the best performance is above the butterfly...way up high.

 It does definitely make a difference in power. It keeps the runner dry and flowing as much air as possible into the cylinder. The fuel in there displaces air, so the liquid is a detriment to a good volumetric efficiency.

 With methanol the difference is very noticeable...the ultimate being "down nozzles" in the head itself. Putting the nozzles down by the valve cover is usually the best a guy can do reasonably and many classes don't allow nozzles in the head.

 With a very dense nitro mixture, down nozzles are a big deal.
 
 Some of the newer pencil-tip nozzles rely on a very small high pressure stream to shoot the fuel right on to the back of the valve and not displace air in the runner on their way there. This almost gets down nozzle performance while being legal in classes where down nozzles can't be used.

 I'm very happy to be a part of this forum! Lots of good people on here. Thank goodness we have Glenn putting in all the hard work behind the scenes to keep it going and up to date. Thanks Glenn!

 Spud

[ricci32]

When I was at the calif hot rod reunion this fall we got a tour of iskys shop after the tour we went to lunch with ed and nick arias three hour later I had learned more on how to make power in an engine and a big thing we talked about was nozzle placement and injecting onto the back of the hot valve and how grains of water in air affects the nozzle size. It was one of the best learning expierence of my life talking with the fathers of speed.

[LZ]

Oh thanks guys.
Stuff to think on I love it.
Spud:
 Did not think about the air stream effect with effect on VE. Keeping the runner dry. Along with this the fuel that's shooting in while the valve is closed.
Friend and I talking recently and he was mentioning an observation with the Jr fuel cars and when they were on the tranny brake.

Larry : You cant just drop three lines on us like that and then stop...  Hoping maybe when you get a chance you could expound on this..Please. How did you get on that lunch? Wish I could have that kind of experience some day. But just to listen. My brain and my mouth dont connect very well. I suck.
Lucky I have a BFF who keeps me on track..

thanks peeps
Luke