rket56

Adding multiple carbs may bring on some unexpected problems. Early on in the game of restoring/customizing my 1956 Olds I decided I wanted to add a 3 x 2 carb setup and an electric fuel pump.
I think the thought of just replacing the old mechanical pump with something more modern and the idea of a cool looking carb system just set the tone for the other changes/additions I’ve made over the years. Ignoring the fact that when I when I finally got around to installing the carb set up I discovered I would have to create new linkage that ran to the other side of the original setup.
In addition, the linkage would also have to reverse the direction and work at a different ratio to work with the transmission kick down linkage. One other thing, I found that the electric pump was going to put out too much pressure, the Hollys can’t handle over 2 psi. So, I bought a fuel pressure regulator and installed it just in front of the carbs and set it to the # 2 setting. After overcoming these opportunities, I thought I had it made. Several years later, when I finally got it running, it was plagued with hard starting when hot, and the carbs seemed to always leaking a little. After a few hundred miles of driving, mostly to iron out other problems I took the carbs apart (Holly 94’s with 1.25 bores) to address some throttle plate sticking issues. I found the float chambers contaminated with what appeared to be small rubber or plastic particles, I guessed the fuel pump was destroying its self, due to the restriction of the pressure regulator. I called the pump mfg. and they suggested another pump
After installing the recommended pump, I also installed a clear, fuel line filter in front of the carbs. Several hundred miles later, I noticed 2 or 3 small particles in the clear filter. I started researching by-pass fuel regulators; they return excess fuel to the gas tank to relieve strain on the pump. I found one that claimed to go down to 2 psi but I still had to figure out where to mount it and how to connect a return line to the tank.
I found that if I turned the battery 180 degrees, moved the main connecting terminal for the + cable and used a longer + cable it opened up a space near the end of the battery across from the carbs. I made a bracket that I contoured to fit the fender liner and mounted the new regulator.
I made a connector to attach to the fill tube on the tank for the return line from the regulator and then put a pressure gage on the regulator and found that even at its lowest setting it was still putting out 3 psi.
So, I added the first regulator back into the system, feeding it from the by-pass system. Using the pressure gage, I had to dial it down to the # 1 setting to get the 2 psi I wanted; there is no direct correlation to the numbers on the gage and actual psi.
I installed another new fuel pump, kept the old one for emergency, and put in a new filter cartridge. About 400 miles now and so far, so good.

oldcutlass

Nice work, sometimes projects can just snowball when you want to be different.

Olds64

Pretty cool!