Hot Rods Hilborn injection question.

On a SBC stacked injection, what is the best starting point for leak down, ****erfly opening and By p*** valve's.

It has 8A nozzles on race gas. I am only running one byp*** now with a .36 spring and the ****erflies are .30

 

I must have missed something... Didn't there used to be a Blown Hemi in that hole?
I have no idea about the number's you're looking for.

 

8A's are pretty big for gas, how big are the stacks ? Mine is 2-1/6" and has 7A's. You might be able to run E-85 with 8A's.

 

7As. ( .021) 1/2 pump. ****erfly’s on .004 and leakdown to 10-11%. Mine is on 13% but I am running a legit 13 to 1. On 110 /race gas. My primary byp*** is .130. My secondary I for got. It it’s written on the bottom of it.
Mine is pretty dang peppy and set at 13 %(which is rich ) I am not afraid to lean on it even with 36 degrees /I am locked.
Look on hilborns site /or old manual they give recommendations based on cubic inches. I am also running a vertex.
For the record this has been a learning curve for me also. Meaning the stacks.
Hat was a lot easier to me. And it was everyone else’s hand me downs.

 

For the first time in my life I have been cautious because I have a lot of stuff on my cars that were given to me be people that aren’t with me anymore. And I was afraid of hurting those parts. Bossman402 /Alky digger/and several other here in the Hamb have helped me a lot. Ask they will help. I ***ure you

 

So you are running a secondary with a pill, I feel like thats what I am missing.
I can't find any old manuals anywhere and the new site ****s!!

 

I actually have a high speed as well. May not use one on the next two. This set up came from Alky and as always there are changes to be made . The secondary has a spring poppet I have spring diameter written down. I am actually considering taking the high speed off.
I think at times it complicates things.
I have another set up I got by way of Gl*** Thames Doug that has no secondary or high speed.

 

Give me a day or so I should have all of that written down some where. I suspect it will be different in the end but I would get it set with the primary byp*** first. Add sec/high speed as needed.

 

These are from my old original hilborn manual that Gl*** Thames Doug sent me. Maybe they will help as well

 

Sorry about the last shot. I’m heading out trying to beat the rain. Yea I know. Never beat Mother Nature yet lol

 

Thats awesome, thanks Mitch!

 

I like to think of the so called "High Speed" as more of a mid range enrichment. Mainly so you can run the lower rpm rich enough that it doesn't melt stuff through the torque peak. I never ran one. But then I was on methanol, so it just didn't matter all that much.
I also think (at least for alcohol) that the barrel valve leak down is more of a starting point just to get the thing to run. The idle has to be super rich. Rich enough to cover the "hole" when the throttle blades are cracked. My own ride was pretty much spitting some raw fuel at idle.
Gasolina....well, I just don't know. Never ran gasoline with MFI. Seems if one is gonna run mechanical injection, might as well run some real hot rod fuel through it!
I visiting Hilborn's website just a few days ago looking for stuff related to another post. Seems Holley has taken 'em over, and all there is on that site is stuff about converting stack injectors to EFI. Fuel Injection Engineering's site has a bunch of tech info as well as parts. I bought a bunch of stuff through them too.
Does Hilborn have a "legacy" site?

 

402BOSSMAN has all the older stuff.Alky digger has an abbreviated version of the original manual /I have both. The advise I was given that has helped a great deal was get ahold of a local sprint car guy if you got one.
Also don’t get to hung up on idle quality as stated earlier. And yes Alky is more forgiving with tune up.
All that matters is that it’s there where the loud pedal is pushed. And fat ( rich is safe ) lean is mean ( as in expensive if you lean it out too much. )

 

Thank you, yes, I always like to have it as fat as possible as it seems like it’s the best insurance for not blowing **** up.

 

Mitchell is spot on for initial settings. Hard to tell in that picture but that looks like the really early version of that injector. Does a magnet stick to the throttle blades? I agree 8A's are a little big for a likely 1-13/16" unit. What cubic inch is the engine?

 

434 dart
14 and 1/2 to 1 compression

 

As of now, I only have a spring poppet, no jets or other byp***es.

 

You need a 2-7/16" at least, that injector you have will choke it off at 434ci. A #8 nozzle would be sized fine for that engine size, you just lack air.

 

I agree that it needs a larger injection unit, but let’s say I run this set up, where is a good place to start with tuning. I’m not sure how many byp***es I’m supposed to be running, not sure if I should run a main jet or just a spring poppet.

 

Yours looks similar to mine, 2-1/16” , what does it measure ?

 

Mine is 2-1/16” with steel ****erflies

 

From Spud Miller , Fuel Injection Enterprise

A high-speed byp*** (also known as a "high-speed lean-out") is simply another check valve in a mechanical injection system. It opens and bleeds off fuel to the return circuit at the top end of the RPM range, thereby reducing fuel entering the engine and leaning the air/fuel ratio (AFR).
To get yours running, you shouldn't need one, until you run it hard down the course. Have you had your pump checked and flowed ? Is your pump a -0 , 150 Hilborn ? That's what mine is.

 

I had spud rebuild it and it
Are you running a main jet or just a spring poppet

 

Like Marty's, these are 2 1/16. Never ran gasoline thru them, only methanol. This was mid 70's, so memory is a little bit foggy. Leaked at about 11-12 % for initial setup to get it running, adjusted until throttle response off idle didn't have a hiccup. 20a nozzles. Honestly don't know what spring in the bip***. Pill size depended on the weather conditions. Used to have a notebook with pill size and weather conditions. Wasn't very scientific, but it was what we had.

Compression was about 14 to 1, Reed cam right around 300 degrees, don't remember any other specs. Timing 38 to 42, again weather specific. Mondello angle plug heads.

There was a night when we ran a 12 % nitro blend. Called Hilborn for recommendations. Don Enriques, recommended no more than 36 degrees timing, richen the idle about 2-3 flats of the adjuster link, and go from say a 90 pill to a 65 or 70. Man that thing was fat! And the sound was very different from what it was on straight methanol. Louder and sharper. Ran out of fuel on the 33rd lap of a 35 lapper. And we had 40 gallons on board...

Ah those were the days

 

I haven't needed mine yet, so I am leaving that up to Spud. On the subject of a Hi-Speed byp***, I ran a blown alcohol 331 Chrysler in a Dragster, went 192, with just a main jet.

 

That's cool!

 

Dave, you know that Nitro is only for qualifying !

 

Nah! It's good for the feature, that is as long as there's not too many caution laps. You pull alongside the other guy in your row, getting the header turnout just in front of his body when under cautions. His eyes will be watering so bad, he'll have a hard time getting going again...

 

Ok here are my high speed specs.
Anyone know how to post a video ( from my phone) I actually got the Willy’s running pretty nice. ( this week - lol)

 

How do you have it plumbed. I download it to youtube first, then attach it in a post.