A-Fuel injector help

Looking for some Injected guys to give an opinion.

Running nostalgia a fuel. 392 AJPE. We are running the short runner "hot heads" intake with a bird catcher. 100 % with the whole 11 gallons going in. Everyone in the class is using this combinatoin and running well...but they all use the 2 hole Hilborne shotgun.

We have to run "a cast alluminum" nostagic in appearance hat. Thus we started with the bird catcher (that is what i had off the blower motor)

When running the nozzles all square, I am seeing the back #7 and #8 run leaner, which I expected. When you look at the way the scoop effect is ramming more air into the back cylinders. That said, I have only moved the "run" nozzles up 2 moves to balance cylinder temp. We only have 6 passes on the motor, and we are brand new to the nitro deal.

All that said, It really has me wondering how much I may be leaving on the table with "hat" program and its possible ineficiencies. I have always though an upright (gerardot) type would work better, but cant figure out how to get around the scoop issue. Does anybody, have any comments on this. There are 2000 ($) reasons to not just try it out.

Maybe some advice on splitters or work inside the stock scoop??

Thanks for your any help.

 

Geradot upright injector with a Hilborn type or fabricated Surfer style scoop, or an Enderle Barndoor injector with the big ol' mailbox scoop?

 

The front end of the hats have no air flow so move it forward on the manifold?
Reverse principal of moving the blower back.
One can even make a plate that blocks some of the front end.

 

upright

Any upright injector should help. However, scoop design can help a ton too.
-L

 

Is the bottom of your blower wide open from front to back?

 

It's an A/Fuel car SoDak. no wind

 

I did consider the DMPE type spacer that moves the hat forward...

For the late model guys with the long runner hogans... How much effect are you seeing in the runner and its combo change? I have considered.. that an upright (that is 5 inches tal)l may act the same as a open box plenum when wide open, and change the efficiency of the "short" runner that the motor seems to like (adams cars run GOOD). Am I out in left field? The air vs pump. 470 cubic inches at 11 gallons, makes us already pretty close to ratio, so balancing cylinder pressure at MPH is my goal.

 

Seems to me with a limited fuel pump size the last thing in the world you want to do is cram more air in without increasing fuel volume. Upright with no scoop would be the hot tip. Tried it for a couple runs did not run any better but did quit killing pistons. I think if we could have made more runs it might have worked out.

 

Any thoughts on the Miller Gibson injector on a short runner tunnel ram?

 

Does anyone know of a miller Gibson injector for sale?

 

Get a hold of Automan, your problems will end there. PM me if you need his number.

Brandon Booher
NHRA TAD #34

 

pbobably not

I don't think I would. His injectors are good for current, non-nostalgia cars. They simply have too much area for your application with a small pump.

I might know where a couple gibson/miller injectors. PM me.

Regards,
Larry

 

Bigger is not alaways better,..its about velocity not volume..!!!!!!

 

Just out of curiosity, roughly what size pump would a modern A-fuel motor run and what's the typical dsiplacement for the engine these days? Thanks.

 

Agreed, but he's a wealth of information and more than willing to talk to people....figured he could point the guy in the best direction.

Brandon Booher
NHRA TAD #34

 

Nostalgia A/Fuel injector

Hello Mike:
Have you considered using a Crower "Hurcules" upright 8 port?
They have 53 sq. inches of vertical opening.
The Enderle "Birdcatcher" has 45 sq. inches.
You could try one without the scoop as mike sullivan suggested.
I like your "youtube" video http://www.youtube.com/watch?v=CEVQumZMOiU
Nice "first pass" !!
Check your messages
Matt

 

The velocity (or potential loss) is what has my questioning a big gerardot type injector. When the butterflies are open it is a 5 inch tall plenum box. That is what has me thinking about a miller type (less than 2 inches). We are running the ajpe 392 top fuel head, and somewhat small runner/valve combo, so velocity is the key. Again, I'm just trying to think about evening the cylinders up at the big end.

Mike ....The no scope idea, I know Murphy runs without, but it is on a blower. And the jr fuel guys run no stacks. I can see it working well to 400 feet, but what about the speed. I would think an aspirated engine would suffer a bit from sucking at a high pressure (16o to 220 mph) area that would be passing over the injector (like blowing over a beer bottle). Thoughts?


But then again, (as I think about this typing) that might keep it nice and fat through the top end!!

Hmmmm.


Matt, inbox now empty, send again. Thanks for the cheer!

Mike