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kball
03-30-2006, 07:20 PM
The FI setup will have to wait until next year for $$ reasons. I'm putting a bg220hr pump in my bb'71. The pump uses a -8 feed line to the carb, and a -10 return to the tank. In the Barry Grant plumbing diagram, it shows the reg. mounted right on the fuel rail at the carb, then going all the way back to the tank. http://www.barrygrant.com/bgfuel/default.aspx?page=85 What i'm thinking is why waste all that -10 line running from the carb to the tank, when I could have the regulator mounted at the rear near the pump and have it dump the fuel right back into the tank with only a few feet of line rather than another 15 ft. of fuel line. Most major auto manufacturers do it like this now. I've been a BMW technician for years and they've been doing this on all models from a base 325 all the way to M5's. It just seems inefficient to run the line there and back twice. It would make for a cleaner install and save at least 100 bucks on line.

speedster
03-30-2006, 07:33 PM
On large feed fuel systems, you want the regulator as close to fuel need as possible. The reason for a return line is so that the pump does not have to overcome the inertia of moving the fuel in the line. Small demand systems don't have a big dynamic range between flow at idle and flow at WOT. Large systems do. If you move the regulator back by the pump/tank you now are back to the old "deadhead" style system.