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Discussion Starter · #85 · (Edited)
Once again I will suggest going with the Edelbrock returnless fuel pump system.
1) The surge tank is built into the system
2) The adjustable regulator is built into the pump, the filter just goes inline between the pump and the rail
3) You dead end the fuel rail, no need to run a return line to the tank
4) The high pressure pump only needs to pressurize about 2' of fuel line and the rail itself, no need for it to pump gallons and gallons in a big circle back to your tank and back to the fuel rail and back to your tank and........etc.
5) A low pressure pump does the grunt work of bringing the fuel forward from the tank
6) The high pressure pump is emersed in fuel, so it is constantly cooled
7) The system can handle 700hp worth of fuel consumption
8) You mount the main pump and surge tank combo somewhere in your engine compartment or, in our GT's, in front of the radiator somewhere for easy accessibility and, if in front of the radiator, additional cooling
9) It is quieter than any electric fuel pump, carb or FI, that I have ever experienced in my modern cars or the one Opel I have it on at the moment
10) No messing around with your 50 year old tank and running a return fuel line inside your passenger compartment. You do run a vent return line to one of the tank's vent outlets

Why would you get vapor lock in an FI system? The fuel doesn't sit in a reservoir, where it can get baked to the boiling point by exhaust heat, like our carb systems do. If you route your fuel line in front of the radiator, then to the carb or FI system, then it's not subject to any heat. Maybe, only a big fuel pump mounted at the back of your car shoving all the gas in your car in a big circle, non-stop, would heat up your fuel enough to get vapor lock.

I've worked in industry my whole life and I have never seen any hydraulic pumping system that requires a large amount of fluid to be pumped in a giant circle, non-stop, to supply a tiny amount of usage. The water in your house doesn't work that way. Hydraulics only activate the pump when needed. Air conditioners only pump their fluid when the compressor turns on. The list goes on. I can't think of any fluid system that needs to supply a very small amount of fluid to an outlet that works the way old school car fuel pumps work.

My new car will be getting another Edelbrock system and this time I will try mounting it somewhere in front of the radiator, maybe on the horn rail or maybe below or next to the master cylinder.
Sounds like a good approach if you have the money. Glad you like your system!

Personally, I am going to put that $500 towards the Holley Terminator X ECU. I choose to save money where I can design and fabricate. But I can’t design and fabricate an easy to use ECU operating system.

that said, I like the idea of being able to install/ upgrade the fuel system and still run my carb for a season until I have all of EFI components ready to install if the edlebrock system can be turned down to 4 psI. That way I can install my fuel pump block off plate and trigger wheel holder.
 

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Discussion Starter · #87 · (Edited)
Today I received my 23/32” drill and 1/2” NPT tap for my fuel rail ends. The first picture is the original extrusion cleaned up to remove the saw marks on the ends so the o-ring has a smooth surface to seal against. The flat spot in the perimeter is to accommodate clear fuel flow into the injector.
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here is the hole drilled out. It was a bit lit a jack hammer at first, but smoothed out once the drill got started.

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Then of course the 1/2” NPT tap that is about o.8” in diameter. It took the 10” crescent wrench to cut these big diameter threads.
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And of course all of this in service of the AN-8 O-ring to AN-6 fuel rail fitting.
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Discussion Starter · #88 ·
my refurbished aeromotive fuel pressure regulator came with 2 springs:
  • high pressure 30-60 psi spring installed
  • Low pressure 3-4 psi for carburetor
I installed the low pressure spring and AN fittings.
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i 3D printed some plastic Jaw covers for an adjustable wrench to keep from scratching the AN fittings.
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Discussion Starter · #89 ·
So, I am working on wiring for my in tank fuel pump. I was looking at an under hood relay box, but it seems that it requires so many wires. For a clean install, I am thinking about the 4 channel MSD solid state relay. It has internal busses, so minimizes messing wiring, but is quite pricey.

here is how I would usethe 4 channels
1) fuel pump relay (this is what started the whole exploration)
2) horn relay (horn not getting proper voltage)
3) fan relay (controlled by terminator once up and running)
4) bonus channel

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Discussion Starter · #90 · (Edited)
Finished up in tank fuel pump build and install, so now it is time for fuel lines. I went with 3/8” aluminum with AN-6 fittings. Started with 90 degree bulk head fittings under tank running to 2” diameter aluminum fuel filter (over kill… it came with AN-6 AN-8 and AN-10 adaptors)), but filters are changeable and readily available. The path is basically the same as the stock fuel line for both the new 3/8” supply and return lines.
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Discussion Starter · #91 · (Edited)
Today I made 2 AN-6 fuel flex lines to run from the bulkhead AN-6 fittings at the back of the car to the new in-tank fuel pump fuel supply and fuel return fittings.

I started by a quick design and 3D print of some soft jaws for my vise to hold the AN fittings while installing them on the flex line. I pressed a few magnets I had laying around into recesses on the back to hold them on my 4” vise.
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I was tempted to buy the aluminum vise soft jaws, but since I was only going to use them this once and I could have the today, I went with the maker solution. They worked quite nicely despite the $0 cost. By the way, it is amazing how easily the AN fittings scratch when using cheap tools, and conversely how a high quality wrench doesn’t damage them.


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Here are the new AN-6 flex lines in the back of the 1972 Opel GT. The tank is tapered at the back bottom middle, so there is a space on each side which I used to run the lines. That said, they will be under the tank, so that is why I went with the high end flex lines and quality fittings here. The other 2 fittings that came in my kit with the line will be used for the flex line to connected the fuel regulator to the fuel rail on the engine.
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The refurbished and modified tank with the custom in-tank fuel pump is ready for installation. I already ran the new hard fuel lines from the rear bulk head fittings to the front cross member. I just need to secure the lines and add 2 more tube nut / AN-6 flare connections.
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Discussion Starter · #94 ·
I am just at a place where I am going to remove the mechanical fuel pump. Do I need to drain the oil for this job or can it be swapped out without draining the oil?
 

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Discussion Starter · #95 ·
Also just refinished running my hard fuel lines. It took every bit of 25’ for the supply and return lines the way I routed it. In fact I had wasted some little pieces practicing my 37 degree flares and left the lines a little long at the back of the car to flare and hook up to the bulkhead AN-6 fittings. I actually did not have a long enough piece to make the turn into the fuel pressure refulator. So, instead stopped at the vertical riser and ran a 90 degree Elbow into the fuel regulator. see fitting below on left of regulator.
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Discussion Starter · #97 ·
Before bolting the refurbished and update fuel tank in place, I decided to sound proof things a bit. I ordered something like 32 sheets of Kilmat adhesive backed butyl soundproofing in on the morning and it was delivered by 3:00. I applied sheets to the area under the gas tank and will bolt the tank in place tomorrow. The license plate holder and taillights are tunneled into the body so the back looks a bit different
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And also applied sheets to the ceiling of the back area as well. The copper pipe is the relocated fuel spout to accommodate the rear wing.
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Discussion Starter · #98 ·
Well I finished up the final bending, rebending, and positioning and securing of the fuel lines today. I had initially just bend the line by hand, but could not get it right
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I finally found a location in the tunnel for the huge fuel filter. And I like the rubber lined stainless tube clamps.
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here is where the lines go through the underside back of the car. I have been looking forward to making those connections at the bulkhead fittings.
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and was able to set the tank in place.
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getting close to final tightening of fittings, running power, adding fuel, and powering it up. Oddly enough, it is going to still be carbureted, but one step closer to fuel injection. This was arguably the hardest part of the conversation job in my opinion.
My universal fuel pressure regulator came with 2 springs and I have the smaller spring in to run carbureted pressure levels.

also for in a crank position sensor and keen to try that with my crank trigger wheel, now that I removed the mechanical fuel pump.
 

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Discussion Starter · #99 · (Edited)
I do really like @The Scifi Guy’s crank position sensor solution. If I had one, I would have installed it in a heart beat, but since I don’t and am a fabricator, I sort of go with what I know, and what is cheap and fun.

I designed and 3D CAD model 3D printed a model out of ABS for test fitting.
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Cast it out of aluminum (I hadn’t melted metal in a while and was keen to fire up the trash can foundry). I have an old alloy wheel I have been cutting up and metaling down, so whole project costs very little.
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cleaned up the rough casting. It was rough, as I was in a hurry and did not take time to degas the aluminum, so there is porosity in the ipper
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a little bit of time drilling and boring holes and talking the sensor mount bolt hole.
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and here is is installed. I will have to check and verify a good pulse signal. I hope I can find a way to do that with my multimeter.
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i think the spec on the air gap is 0.8 mm +/- 0.3 mm. So that is roughly 0.031” which is roughly 1/32”. For that reason, I cast The sensor mounting plate on the thick side. If the gap is too big, I will just machine it down a bit.
 

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Discussion Starter · #100 ·
To polish up the melted lips (novice TIG welder) on the new injector bungs, I bought a 90 degree adaptor for my Dremel tool.

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theI 3D designed and printed a sanding Mandrel just slightly under the diameter of the fuel injector bungs the same depth where the
And pushed it (friction fit) onto one of my extra dremel sanding disc shafts.

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Then, I cut some 320 grit sandpaper strips 11 mm x 50 mm and sprayed a bit of adhesive on them to hold it to the mandrel.

I also designed and printed a fake fuel injector plunged that just barely fit inside the bung with no reistance. I used this as my tester to verify whether more sanding was required. I was amazed at how well this system worked!
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Discussion Starter · #101 ·
Regarding mounting of the fuel rail. I am thinking of drilling holes for 2 bolts right between each injector pair. See location indicator by red markings on manifold picture below.
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And to hold it in place, I used modeling clay which was easy to squish in place and fine tune for alignment and shape it and cut with a knife.
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I am thinking about casting these mounting Blocks out of aluminum nd TIG welding them to the intake runners. would drill and tap them with 8 mm bolts and drill corresponding holes in the fuel rail.
 

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Discussion Starter · #104 · (Edited)
Make sure of two things:

1) you have the fuel rail perfectly parallel to the injector bungs

2) you have enough ‘crush’ or preload on the o-rings

It’s really easy to let either of these shift during fabrication. You just need 5 hands to do it.
Got it. Thank you for the guidance and support even though I am doing it a different way. The way you made your fuel rail mounts is quite beautiful and I don’t have those types of parts laying around or those particular skills.

those tips above are going to be key for a leak free system. By the way I am just loving not having my opel or garage smell like gas. One fix was the pinholes in the fuel tank. The other I just found today was a hand tightened AN-6 at the return line coupler. Just needed to snug it up a bit and fuel smell is gone in the garage!

One other mistake I made that I purchased the larger 0.580 inch (i think) bungs for the LS3 injectors, rather than the standard 0.540” injector bungs. I love the technology and how short the LS3 injectors are (about 1.5”), but the lowest flow ones I can find are 42 lbs per hour. So, these are a probably a no go. I am planning on roughly 24 lb injectors which should be good for close to 200 HP. I am thinking about Chevy truck engine injectors as they are only about 1/4” longer, are very well characterized, and standard is 24 lbs per hour, but are designed for 0.540” bungs. To compensate I am going to purchase some special o-rings that allow for use of these injector in the larger LS3 bungs without leaking.
 

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Discussion Starter · #106 ·
As part of getting the electrical system ready for EFI, I upgraded the alternator, bypassed the amp meter, and connected a charging wire directly to the battery from the alternator.
I have found the cigarette lighter located volt meter to be a nice way to monitor the charging system.
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Today I installed a heavy 4 gauge ground wire directly from the battery to the engine block at the alternator read mounting bolt. . Previously the battery was grounded solely to the chassis. I left the engine a lock to chassis copper strap in place after a good cleaning.
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Discussion Starter · #107 ·
But this last time during the tack-welding stage I was a bit surprised at how much movement you could get between the rail and injector holes and still have the o-rings seated. Probably 15° either way!
Thanks for sharing this. In that case, i will sequence things like this to minimize degree of misalignment.
  1. Weld the aluminum spacer blocks to the intake runners.
  2. Drill mounting holes in fuel rail
  3. Drill holes in spacer blocks (after marking them through the fuel rail holes
  4. Tap holes in mounting blocks for mounting bolts.
 

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Discussion Starter · #109 ·
Where did you get that usb and volt meter gauge at? I would like to get one and put it in my cig lighter hole.
I got it on Amazon. It was only $10. I chose this one because of its simplicity and also the chrome bezel on black aligned with the design cues of the other Opel GT gauges on the dash.
Here is a screen shot for your convenience. It has helped me once again this morning when I saw the voltage go low with the headlights on and realized the battery needed a deep cycle charge after sitting for several weeks and all of the electric fuel pump work.
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Discussion Starter · #112 · (Edited)
Back to the EFI fuel rail hood down fixtures. I started out with clay mold but ended up 3D printing iterations to get the angles right and am keen to melt and pour some metal today. So, I added about 4 degrees of draft to the sides (so I could cleanly remove the mold from the sand) and added about 14% to its size to account for shrinkage of molten aluminum to solid aluminum and machining. I am going for a double casting as I need two of these.
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here they are in the sand / powdered cat litter homemade casting sand mixture.
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The plastic models pulled clean from the packed sand mold. And I used one gate that fed both pieces.
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And here is the casting 11 minutes after the pour. still way too hot to touch!
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and plenty of extra molten wheel alloy aluminum that I poured into my rusty mini muffin pan for next time.

reasonably nice fit after a little time on the belt sander with 60 grit.
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However, I am going to hold off on TIG welding them to the intake manifolduntil I have my fuel injectors in hand for final fitting.
 

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Discussion Starter · #113 · (Edited)
I FINALLY ordered fuel injectors after months of pondering. It was a highly constrained problem. Here are the constraints I worked through and it is a battle to get the injector characterization info, as injectors are usually sold as an OEM part or OEM replacement. And most performance injectors are too large for a naturally aspirated opel application.
  1. Short as possible in length to accommodate desire fuel rail location.
  2. Right flow: Close to 20 lbs per hr
  3. Newest injector tech (ethanol compatible, higher pressure, better atomization, faster response time)
  4. Characterized / dead time data (for ECU)
  5. Affordable
  6. Large bottom O-RING to match 0.580” bings I welded in to the intake manifold.
I summary, I wanted an LS3 type pico / shorty injector in almost every way, except that they are pretty big 42 lb/hr and up. I was concerned about idle quality, so kept hunting. I almost settled on GM truck injectors, but finally found the Bosch EV-14 injector, at ~ 22 lbs/hr.
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The Bosch 0280158091 was OEM on Fords and Mazdas with 3.0 liter 6 cylinder Ford engines. They are very similar to the GM LS3 injectors Bosch 0280157051 which are 42 lbs / hr. I am hoping that right size the injectors will give me a good idle. 22 lbs / hr x hp / lb x 4 injectors should support up to ~ 176 hp.

I have been going back and forth with Bosch the last few days trying to get the injector dead time data. They called me back twice, but I was in the middle of conference calls and could not answer and haven’t heard from them since.
 

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Discussion Starter · #114 · (Edited)
I took a cue from Gordon the sci-fi guy on making a distributor block off plate. Long term, I like the idea of the RallyBob distributor cut off for a clean look. Very cool idea to cut the shaft and cut and tap the housing for a pipe plug.

For now, I wanted to smoke some meat and cast some aluminum this holiday weekend.

So, I designed a 3D distributor block off cap and printed out a 3D model.
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I had a hard time pulling the model cleanly out of the packed sand mold, especially on the inner cup side and the logo. So, I tweaked and reprinted the model several times with increasing amounts of draft (slanted walls) finally got it to pull relatively cleanly.
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then of course the fun part of melting down aluminum in my mini garbage can foundry.
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here is the hot casting.
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then I cut off the sprue and gating system and used a boring bar on the mini mill to clean up the inner lip.
I smoothed out the top with a few grits of sandpaper and the orbital sander and hit it with the buffing wheel. It shined up nicely and fit on the distributor. But, I was disappointed with the level of porosity. Not sure if it is hydrogen in my melt or steam. It seemed like a really good pour (kept the sprue full), but maybe it is because I forgot to add stream vents.

And a little bit of black paint to make the logo pop.
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Here it is on the opel distributor.
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It is so fun and rewarding to make car parts from scratch.
 

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