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> Fuel pressure regulator, Where to locate in engine bay
North Coast Jim
post Nov 30 2016, 05:11 PM
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My new 2056 engine running 44IDFs has now about a 40 miles on it. So cool to have this car back on the road after 25 years. Runs way to rich with a 160 main, 175 air correction, 60 Idle jets and a 36mm venturi. Continue to have a problem with popping through the carburetor at partial throttle. Fuel pump is the Carter rotary with inline filter along with their SS lines through the tunnel purchased from Tangerine Racing. Engine builder wants me to install a fuel pressure regulator to eliminate this as a variable. The jetting exercise can come afterward. I bought an Italian made "Petrol King" diaphram regulator with single outet. Will hook up serially the pump/ filter/ regulator / guage than "T" off to the two carbs. I'd like to hard mount this device but where ?? To the body or to the engine ?? I'm sure this has been done before. Any suggestions. Pics would also help. Thanks World
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jmill
post Dec 1 2016, 10:30 AM
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If you had a lean pop at the top end of a hard pull I'd suspect low fuel pressure/volume problem.

If you lift the needle valve off the seat and you spill fuel out of the carb I'd suspect a high pressure fuel problem.

Part throttle lean pops are because you get off the idle jets prior to the main jets coming in.

Solutions

1- float level is low which delays the mains from coming in.
2 - vents too large which delay mains from coming in.
3 - ET tube selection
4 - accelerator pump jets plugged - low volume

Idle jets require a pressure differential above and below the butterfly to draw fuel. When the butterfly opens, that DP decreases until there is no DP. The main jets then require enough air velocity through the vents to create a pressure differential to draw fuel through them from the fuel wells (Bernoulli's principle). The larger the vent the lower the air velocity and the lower the DP.

The name of the game is to have the mains come in at the same time that the idles go out.
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