Hot Rods Hilborn injection question.

When I was running with Joe Fontana and his 12 port GMC in my roadster he would come down 2 weeks before speed week to run the engine. Before he drove to my garage where all the ***embly was done I would set the barrel valve with my air compressor at 100 psi at 8% leak down with the ****erflys all at .003” with a feeler gauge if this is your original question.

We would start it on alcohol with a nozzle that had twice the area square of a Hilborn #7. I have a chart for areas of orifaces. We normally had 110 byp***. It always started right up with minor idle speed adjustments.

Before leaving for Bonneville I would put in the nitro nozzles for 75% and a byp*** of 65 for starters. When you are adjusting the idle speed up or down with the ****erflies you are slightly opening or closing the barrel valve. Rarely did we ever adjust the barrel valve and we did it by listening.

Joe called high speed lean out byp***es “blow ups”. In his opinion all they guaranteed was a blown up engine. We never ran one and the byp*** we did was in the middle of the line back to the fuel tank so it never saw any vibration.

Hope this helps

 

Sounds like you didn't run a spring poppet, just a 110 jet, maybe thats the route I should go. I think most of my tuning is in the barrel valve.

 

It is plumed off of the fuel pump back to the tank

 

My secondary is mounted directly to the barrel valve. ( drilled for a return Then back to tank. )
I would put everything as close to the tank or pump as possible souley for access reasons.I am seriously considering not putting a high speed on either the prefect and the opel kadet.
Need to see if I can down load video.

 

No there was a spring poppet. Standard for a byp***; it’s only for starting with the spring keeping the pointed end closed when there is no pressure to byp*** fuel going to the tank when you crank start.

 

Installed a 110 jet and no poppet and she rocks!!!

 

Good deal.

 

Well, my car likes a 65 main jet and a soft spring, runs awesome!

 

On my big 4 cyl with a Boss 429 head, I was told to start with a 95 pill and .023 nozzles. It ran with that but I now have a drilled pill at .136 and .019 nozzles. I have a A/F gage, still says fat at 11.4. My eyes and nose also say it's fat. Also 2 pounds fuel pressure at the nozzle, but the darn thing runs! It just frys tires!

 

My eyes and nose would agree with you on that!

 

Is there a big difference between methane(race) and E85? pros and cons?

 

I have been doing research on E-85, and this is one thing to consider,
E85 gas (also known as flex fuel) is a high-level combination of ethanol and gasoline that consists of 51 percent to 83 percent ethanol blended with gasoline. The percentage of ethanol depends on the geographical location and time of the year.
So tuning can be a real problem, unless you can find a savvy supplier in your area, to maintain consistency. Plus it is corrosive like methanol. I plan on race gas for mine, to get started.

 

Need to test it before you buy it.

 

As a side note, to determine the ratio of ethanol to gasoline in pump E85, there's a simple test. Take 100 ml of the E85, and mix a small quan***y of food colored water in it, say 20 ml. This will cause the gasoline to separate from the new water-ethanol portion, which will be colored differently than the gasoline portion. If it is actually 85 % ethanol, the gasoline portion will be 15 ml, and the remaining stuff, will be the sum of the ethanol and water, 105 ml.

We did this routinely at the lab when we were researching the emissions effects of the varying concentrations. The chemists here call it breaking the aziotrope (spelling???), a fancy 10 dollar word they were fond of.

An inexpensive 500 ml plastic graduated cylinder is really the only tool needed. Well worth the cost and effort if you are serious about using commercial E85.

 

Following this thread hard .
I have 7A nozzles on mine ( same as the OP's 2 1/16" )
I have never ran it yet . Im told it was on a 327 on gas .

Book marking it . All ears here
My set up is in my avitar

 

I emailed with Spud Miller about all this stuff on the street. He’s the man and he basically talked me out of trying it. ( I’d still like to try it regardless) He cautions that the hard part, as we all know, is there is no midrange. Consequently, at midrange the motor is either extremely fat or extremely lean. I still think about trying it though. ‍‍

 

Yeh, Spud is right but it can be done, I don't think you would like it as a daily driver though.


This car is one year OT for the HAMB but this is a good article.
Here:
https://www.driveonline.com/from-the-magazine/augie-delgados-flashback-66-nova/

 

I heard that a Jackson unit, like on Augie Delgado's Nova, is the best candidate, due to the higher location of the throttle plates.

 

I think that surge tank is kind of the secret. Or part of it.

 

I have been told that for gas the nozzles should be up as high as you can get them. On alcohol as low as you can get them. Mine is on gas, the nozzles are 14 inches from the head of the valve, another 2.5 to the ****erflies. I have a problem of running fat, but the way it is now I have no problems mid range.

 

I think I am going for a 20 A nozzle!

 

Cool thread....

 

I went with a 24A nozzle per Auggie's request and she runs great!

 

Side note:
On my Hemi, I can't tell if the engine is running lean or fat!
On gas it's easy to tell by the dark smoke exhaust but it's a little more difficult on Alcohol. I started with a 90 main jet and now I am at a 75 main jet and it looks the same.

https://www.youtube.com/shorts/LDn0BLPc8yQ

 

You should be able to hear Lean /rich @ ideal , Crisp revs richen up 1-2 flats rich.
Use Shiny / sliver plugs,
look @ edge of plug where threads start
(ring edge ) for 3/4s to 7/8s heat stain , If dull all the way around 360degs rich,
If 1/2 of ring dull, 1/2 shiny Lean, Easer with a O2 gauge

 

And the gag factor...
If you can breathe a little bit, it's lean.
If you have a hard time catching your breath, it's close to correct.
If you are gaging, eyes watering, and it is almost impossible to catch your breath, it's fat.

Probably not the best way to go

 

This is interesting. I have never heard this.

 

Should say these are WOT plug readings. Ideal has nothing to do with using it as intended.

 

I think a data recorder might be an awesome tool initial setup. Make a p***, then make some adjustments. Circle track guys use them all the time. You might be able to borrow one for thr weekend.

 

It’s not been mentioned but I believe a #7 nozzle from Hilborn is .021”. When I went to Enderle to buy nozzles for my GMC 3 intake port Algon injectors due the fact the single nozzle had to feed 2 cylinders and fired twice where a single nozzle engine fired once I told them I wanted .029” nozzle pills. The guy helping me said no for gasoline I need .021”. After I took out a chart with areas of orifaces in square inches and said it had to fire twice instead of once. He looked at the chart and said “ can I make copy of this?” and said I was correct. The chart came from Les Leggitt.
I was told 50 years ago the “A” behind a Hilborn nozzle means angle.