Technical Fuel injector Fab

So not entirely sure why I did this now - would have made a lot more sense to have done this earlier. Hindsight's 20/20!! In case you're wondering I added a 3/16" thick protrusion on the bottom. If you look at the pic in my previous post (on the kitchen table) you can see a small gap in the rear of the scoop. Same issue as the originals. I could have fixed that with some weld right there or this protrusion. I chose the protrusion so I could machine a skim cut later truing up that surface. I think these subtle details are what will set this apart (or I hope so)

 

Looking like it'd be a lot better to put the barrel valve in the rear. Other than making the fuel lines longer - I'm not sure of any other downsides? Any comments are welcomed! BTW my plan was to fab the barrel valve (and eventually I will) but when you drop by Barb Hamilton's garage sale and there's a box of fuel injection parts - you grab them!!!!

 

Time to thread the body for the nozzles! BTW these are NOT the hoses that I will use. I was only mocking up with some old hoses to see what lengths might be good.

 

A quick hit with 120, 240. 320, 600 (wet) and then onto the buffing wheel. Not done but gives a good idea what it's gonna look like.

 

Im sure you checked to make sure the rotation was/is correct

 

Yes, I have EXCEPT !!!!
I have yet to understand the purpose of the OFFSET for the INLET FUEL and the METERING VALVE - and if that has a relationship with the direction of rotation. Seems like I saw that explained somewhere, but I forget where. Seems like it is just to ensure a straighter shot for the fuel to travel and shouldn't matter for rotation, but I want to really look at it to be sure.

 

The spools either have a lead-in slot (lead not lead) or groove that get bigger/wider as it rotates before it opens up all the way, or it has a hole that sort of does the same thing

 

Yep, The ones I am familiar with have the slot and a hole. the slot is ramped (on both sides so you can rotate CW or CCW) and the hole is for the idle check which gets covered quickly upon acceleration and prevents dead heading the pump on deceleration (at least that's my understanding). I just couldn't recall what I once read about the orientation of the offset - it was probably just a reference so everyone was starting at the same refernce point. For what I was wondering - I can't see it making any difference whatsoever. The symetrical ramps ground on the metering valve will let me set it up either way. Of course YOU know all this - I am still learning Like my tagline says "with the help of some..." Thanks for your comments. They are truly appreciated!!! EDIT: I want to CORRECT this as what I previously wrote is somewhat misleading. The spool aka metering valves are OFTEN ground symmetrical, but depending on your metering block offset DOES have a relationship whether it should rotate CW or CWW - you can't just assemble these have have them automagically work - you have to look at what's happening in there to be sure. There are lots of guidelnes, but it's better to just peek inside IMHO.

 

These comments remind me of when I FIRST fired up my dragster with the stack injection. Checked and double checked everything. Primed it and it LIT RIGHT UP and promptly stalled. We repeated this a couple times before STOPPING to see what I goofed up. The experienced guys already KNOW that I had the pump rotation wrong. Lesson learned. You cannot double check what you don't know!!!! Always learning with the help of fellow racers and hot rodders!!!

 

A peek under her skirt.

 

Man, If that runs as good as it looks, you should be in for a hell of a ride. This tech is way beyond my my skill set, but still fun to watch. Thanks for taking us along for the ride.

 

You are quite welcome. I thank everyone for taking the ride with me. Bouncing ideas and sharing of information is what it's all about! I sketched and modeled up a few ideas on the idle and throttle stop part and I really like this last version. You can add a second screw if you want to make both extremes adjustable, but I probably will just have the one. I may incorporate the throttle arm into it - can't see why not- so far.

 

The first arms seem to work well other than it's hard to get to the idle screw on the barrel valve side - I think I'll make another arm with a longer protrusion. Gotta dig up some more scrap!!!! Or maybe put the screw into the base instead - it's not like a carb where you have to do it with the motor running!

 

nice work! you guys all have so much talent! my old man was a machinist, and I have a deep appreciation for your work. anxious to see how it all works out!

 

The slot must be on the wide side. The side with more materiel between the fuel fitting and the side. You will run lean if you go the other way. I picked up 7mph at El Mirage by just turning mine around and doing it right.

 

Can somebody show the slot you are talking about?

 

Here's a sketch showing the SLOT we're talking about. There's a relation between the Slot and the number with the offset for the fuel inlet as shown. This is how I understand it - which I believe matches what Hilborn publishes and looking at it here makes sense (to me anyways). The slot on mine is symmetrical so what I was saying earlier is that I can't see any difference if it's rotating CW or CCW WHICH sounds good but WON'T FLY if you have the idle bypass hole - which you really want. That's the point I think Rich was making. And Thanks to Rich I went back and edited my earlier post so I wouldn't misguide anyone.

 

Thanx!

 

On mine and all I have seen, if you look at the metering block from the top. The fuel fitting is closer to one side than the other. The slot should be on the wider side. That was my point. Of course I am talking about Hilborn metering blocks. If you are making your own, I guess it wont make any difference.

 

Rich, Here's a link from Hilborn's site:
http://hilborninjection.com/faq/how-to-set-the-metering-valve/ it is a tad misleading because they show the metering valve (rotor) on the same centerline as the fuel inlet. The metering valve is centered on all of the ones I have and the fuel inlet is the offset one. It's kind of counter intuitive (for me anyways) but makes sense when I draw it out. My sketch would be looking DOWN compared to the link I attached. I believe mine matches the link. I am likely using poor words to describe it (hence the picture). It makes sense to me that you offset the inlet fuel to the side of the rotor slot - straighter path for fuel to flow. My sketch may be confusing since it isn't clear that the spool is basically centered in the block. I took some pics to see if that will better show what I am trying to say. The ones on the LEFT are at IDLE with the bypass hole visible in the rotor. The ones on the RIGHT are at WOT - IDLE bypass now blocked. In this case the "offset" of thin side is towards the TOP . At WOT the rotor number is on bottom(I was hoping that would show in the pic). I believe all this is matching the Hilborn site and my sketch (as bad as it is). Not sure what am I missing? I am NOT trying to be argumentative - please don't think that. I am trying to make sense of everything.

 

In your picture 2348 you are showing your slot towards the narrow side of the block as looking at the location of the fuel inlet hole. That is wrong. In operation the slot should be on the other, wider side. You will have a restriction with the slot as shown. The secondary bypass hole really is not important. It should be straight up open at idle. I cap mine and don't use it anyway. It's purpose is to bleed off a pressure surge when sprint car guys chop the throttle entering the corner. I don't do that on the salt.

 

Thank you for the kind words. I am by no means a machinist. But I do know a couple and they steer me in the right direction from time to time!!!! Having good friends can be priceless!!!!

 

I looked at the Hilborn sketch. I see what you mean about alignment of numbers and such. I never pay any attention to the location of the numbers. I just want the slot to be on the wide side. Just barely visible at idle and rotating up toward the fuel fitting as throttle opens.

 

Rich, I hear your words and I wanna think I understand, but it falls apart in my head and when I sketch it out. If I orient it as you suggest then I see it being restricted. Check out my attached sketch. I drew the Slot in both orientations and can't help to think that it would be restricting fuel flow if I orient it towards the "wide side". Color me confused.

 

I think at this time, what I hope you do is send n email with the picture #2348 to Hilborn and ask them. Just ask if the slot is correctly orientated at WOT on the narrow side. Tell them some guy on the HAMB keeps saying it should be on the wide side, But you all know what kinds of people hang out on line. And report back so we will all learn something from all this. Nice scoop. Way out of my league.

 

Rich is this where I learn that you retired from Hilborn or something similar??

 

No such luck

No such luck.But I think that is where you can get an answer you can believe in.

 

Rich, I have a friendly challenge for you. Take a barrel valve, install the spool with the slot to the narrow side, now blow into the inlet. Repeat "test" with spool slot on the wide side. There is a very noticeable difference. Hint hint, I just dreamed this up and tried it several times. Rich, again ThankYou for taking the time for ALL your posts. You have made me think about how this works and challenged my grip on the subject as well as encouraged me. I truly appreciate it.

 

I would if I could. I have sold almost everything I had to keep it from getting thrown out when I'm gone. The only car I have any connection at all to now has a Don Jackson hat and a total of 93 nozzles. I don't know how he came up with that number. 400 psi fuel pressure with a RAGE Fuel Systems 2400 pump. All way to high tech for me.

 

Today I looked around to see if I had a metering block somewhere. No luck. But I did find lots of pills of many sizes and a nice pill holder. Along with a -6 three way shutoff. And many nozzles. All of this could be yours for $35 and shipping if you act soon. But wait. There's more. If you want them I will also include a bunch of old hard hoses that you can salvage the ends from. I was always going to. But never did. Correction: It looked like a -8 shutoff yesterday. But looks like a -6 today