The tasks of the day started small, and ended up with a few big to-do's.
I took a few days off of work to work on the car. First, I noted that the cooling fans (dual electric) are probably not done right. So, I ordered a few parts to re-wire, plus to get a good switch to turn them on and off properly.
Next, I brought my neighbor over to help me get the timing set on the car. Before, while talking with him, he kept saying "fuel, not timing". But, since I had it somewhat running before, and only messing with the timing until I couldn't keep it running, it really had to be the timing. Right?
Really, right?
No. We worked on the car for a few days, checking plugs (one wire burnt), etc.
It very nearly ran a few times. I spent hours using a syringe to squirt fuel into the carburetor fuel bays to fill it up to the sight holes. The poor guy spent two days with me, and regularly said "fuel problem."
So, after getting tired of squirting gasoline into the fuel bays on the carburetor, and he again asked how the fuel pump was and if I verified that, I decided to look at the fuel filter (one of those fancy glass ones so that I can see how clogged it was getting.
Bone dry. Sometimes, guys just don't listen, do they? Okay, the pump is bad. I looked at the Edlebrock fuel pumps, but opted for a Facet (I hear better things about Facet than I do Edlebrock regarding this style of fuel pump). On Napa, it's a BK 610-1050 .
- 32 gallons per hour
- 4 to 7 PSI (perfect for a carburetor)
- inline, and not in-tank, because I'm not dropping a fuel tank to hack together an in-tank and a fuel sending unit
- While it is intended to push, this one can be set up close to the tank, inside the frame, and pull a little bit of fuel
We'll see how this one performs over time, if it is sufficient. I already have a fuel pressure regulator, just in case, in position.
Knowing I need to get the fans into a better wiring position, and knowing I needed some electrical for the pump, I suddenly went into to-do mode for this, since I have worries.
Here's the to-do's :
Better wire looms to prevent burnt wires.
I really need to get them past the headers, and the #2 cylinder is really bad on the angle. If I run the wires between #2 and #4, it will burn, so I have to run the #2 wire over and around the exhaust pipe. While here, I will actually use some of those heat covers, to see if that also helps.
Build a wiring harness for the electric fuel pump
I mapped out the wiring diagram, looking for a good spot to tap into for both the electric fuel pump as well as the cooling fans. The best I could find on this car is the wire that feeds the HEI distributor, because if the car is running, those other two need to also be running (or be able to in the case of the fans). There are two wires from the front of an HEI distributor, a brown one that routes to the tachometer inside the car, and a pink one that routes to the ignition switch.
So, I ordered some much-larger wire in "pink" so I can match, and then mapped out two and a half wiring harnesses. (The half is because I'm planning ahead on the cooling fans). First, arrange the components of the harnesses (including relays).
Then, cut wires to length and solder them together.
The wires were each done in a specific order so that I could also slide heat-shrink tubing on and seal them up.
Once each wire was soldered into place and sealed up, I commenced wrapping with a wiring harness fabric tape.
Now, I do have a "wiring harness". It can't do much until I connect all of the relays. Again, laid out with relays "in position".
The Painless wiring harness (50102) I used has a ground wire that is short. But, since this body is fiberglass, there's not a whole lot I can do, because fiberglass does not conduct as well as we all hope. So, a few relay housing wires get swapped so I can run a longer black wire along with the yellow one for the pump. I ordered the inserts that can be put into the relay housings, and crimped them into position. I then soldered the connectors because I have this odd fear of corrosion getting too far in, and also getting shaken loose. So, soldering.
One issue is that each relay housing has two different types of connectors inside, so I had two different connectors. The connectors were the 6.3mm (they are really 1/4" connectors, but the invasion of the oriental supply chains force measurement in metric). Now, one of them I ordered had tabs on the back that were too long.
Rather than ordering new ones (and hoping I could find perfect ones because no one lists the actual data on the tab length), I just grabbed the dremel and chopped it off a little shorter. Then, replace the wires (I'm using uniform colors, so someone using a wiring diagram for this car will know exactly what it is).
Granted, at this point, a basic relay and relay housing would have been cheaper than a Painless harness, but I was already there, and I didn't want to order and wait again.
Next, I added connectors on the ends for things like the fans as well as the fuel pump itself, and also the pink ignition wire running to the distributor, and next I tackled getting it installed.
I cut the pink ignition wire to the distributor, and installed a connector on both ends of this, then clipped everything into place. It took a while to get it routed where it needed to be, to get the fans hooked up, and to get the wires to the fuel pump installed.
Harness is looking good!
Electric Fuel Pump
Next, it was time to get the pump installed. I did remove the old mechanical pump, and installed a pump block off plate.
Now, knowing I have to install better lines, I converted two of the socket head bolts for the block off plate into "studs" by using stainless all-thread and machining a round-but-hex stand off.
I wanted to place the pump along the frame rail, however, I had only 8" of length to place it and it would have hung under the frame about a half inch. This was unacceptable to me. So, switching things up, it has to go into the tank. That means, I have to get to the fuel sending unit, and install an in-tank pump if I go electrical. Since I'm also doing this with the future to install fuel injection, it also means I need a fuel pressure regulator that will adjust low enough for the carburetor, but will also have a high enough pressure for when this gets injection. Now, Tanks, Inc sells full tanks ready to go for the C3 Corvette, but surprisingly, this does not list a late model C3. Holley sells a fuel pump sending unit that is a direct replacement, and that may be an easier way to go. But, I don't want to spend $500 when I can use the pricier form fuel pump for $60 and some brass fittings.
So, drop the tank. Swear a little because the bolts holding the tank straps in place are spinning freely and the bolts won't come loose, so run to Harbor Freight and grab some curved wrenches, then take them to the bandsaw and chop them so I can get them into the area I needed to lock the bolts.
Okay. Let's try again to get the tank out. Woohoo!
While there, I noticed that the sending unit did NOT have a gasket. This is likely because the fuel tank originally had a bladder inside that also clipped over the edge. Without it, I have to create one. I spent time trying to figure out how to photograph and use a laser cutter, only to realize I could be done before I even finish preparing images. So, a 12"x12" piece of fuel-safe rubber and a compass with numbers was implemented.
I then used a few of the wood clamps to put it into place on the sending unit, and then traced the holes using a silver-colored sharpie (because it shows up best on black).
Drilled and re-aligned to the sending unit, it will be perfect..
Now I can get back to modifying the sending unit.
I ordered some tube to create a bracket, however, I realized I can easily pull the sock off the tube, and add compression fittings to simply hook a pump up. Granted, I did have to turn off the hex on a 3/8" hard-line to turn it into an adapter.
Then the compression adapter mated up and allowed the pump to be connected. I drilled two holes for the wiring for the pump, and installed it.
I simply needed to finish the wiring to connect the engine bay relay to the fuel pump and install the tank, and connect the tank up to the fuel lines into the engine bay.
Yeah, I built an "adapter" (really, it's a restrictor) to force return lines and feed lines through the same diameter.
With that installed and fuel return and fuel pressure regulators and filters were all installed, it was time to get back to timing this thing.
Cooling fans
On the wiring harness war front, I had one issue that was critical, but at the same time, not critical - mounting.
The double-relay assembly needs to be mounted securely so that it doesn't bounce into the fans or onto the exhaust and get fried. This means potentially designing a part that fits on a non-uniform, curved surface.
I loaded up the Skanect tool, grabbed the XBox Kinect and the USB adapter, and ran a quick scan on the engine compartment.
Exporting to a PLY file (a triangle mesh), I could get a basic 3D model of the fender I need to fit this to.
First step was getting the orientation proper. I created a cube that allowed me to adjust for size. I shrunk the cube to fit in a specific spot, then found my scale options (I have to increase this 888.15789473% once I have it defined properly).
I tinkered with the cube until I got it the right size (I'll re-scale it once I have it proportionally good). Then, I added tabs to create a basic bracket (no thread holes yet because I don't know the angles quite yet for perpendicularity to the inside surface).
The next step on this was to convert the mesh object to a solid. Knowing how many faces, it is exactly why I avoided re-sizing the scan and instead re-sizing the bracket both before and after). This took about 8 hours to process.
Then, it was simply a matter of a boolean operation to cut the scan from the "bracket". Again, because of how many faces are involved, this took a long time. Be patient.
Clicking the mesh object in the tree while in "Part" view, and then clicking "Part" and "Convert to Solid". I used a 0.100 tolerance for sewing the shape. Note that this will take a lot of processing power, so be very patient. If it works, you can move on.
Then, it was simply a matter of a boolean operation to cut the scan from the "bracket", or so I thought. Again, because of how many faces are involved, this was taking a long time, so I exercised patience... until FreeCAD aborted.
[sigh]. A different approach?
Nope, after taking a different approach, FreeCAD kept aborting on me. Apparently, there were too many faces in that scan that I was using for a reference.
So I gave up and bolted the relays directly to the fender. I'd already installed dual fans, and new wiring, so it was a matter of putting the right connectors on the fans, and hooking them up.
Now, that gives me a good connection, and I trust the cooling system now.
Fix the starter solenoid wire (the purple one hanging down).
While working on the timing, I noted the solenoid wire from the key switch was hanging down at the starter. This was fine, since putting the car in drive enabled the other wires and I was using a remote switch (I'm not climbing in and out of the car that many times while troubleshooting). So, I patched that one up.
Testing
Now I can finally get back to trying to time this thing.
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