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I don't know that regulator to tell you either way, but it might work. If it were me, and I wanted cooler fuel, I would pick adding the T at the carb. If you put the return down there at the regulator, fuel will be sitting still in the line to the carb and pick up heat. Of course if it were me, I would want the regulator right at the carb as well.
Good Luck
I don't know that regulator to tell you either way, but it might work. If it were me, and I wanted cooler fuel, I would pick adding the T at the carb. If you put the return down there at the regulator, fuel will be sitting still in the line to the carb and pick up heat. Of course if it were me, I would want the regulator right at the carb as well.
Good Luck
Think that's it. I'll do the "T" as I have seen with Lars set ups.
Rookie suggestion: If possible.......use a temporary pressure gauge to confirm how much pressure is actually going into the carb with the engine idling and also at 2,000 rpm.
Example: I installed a return line at the carb when I used the 50 p.s.i. in-tank fuel pump to supply fuel to the carb after I went from a throttle body to a Holley 600 cfm carb/with the gas cap off, I could hear the return fuel flowing back into the gas tank....I was surprised at the small orifice needed to be in order to drop the carb pressure from 50 down to 7 p.s.i .............I think the orifice was about .080 " diameter.
From: Las Vegas - Just stop perpetuating myths please.
Never seen anyone use the gauge port for a recirc but the gauge port is at the reg outlet pressure and if using a orifice restriction i dont see why not for a return line. Anything down stream of the reg prevents the fuel press to carb from "dead head" and electric pumps or the carb needle and seat dont like that. Your tank return line should be very close to that reg location and a short piece of flex line should work very well. Your '78 should have a return line to the tank unless its been removed. Thats a clever reg mount on the fuel pump casting pad.
My self i like the return to start as close to the carb as possible and of course use a tiny orifice restriction (0.040'-0.050"). I think i see a holley carb in your pix and a possible location is the opposite side inlet (drivers side) to the fuel bowl. That should already be threaded but u will need another mile of fuel line to go around carb and down to the tank return line (well maybe only a couple feet) but attachment/installation could be fast and simple.
Never seen anyone use the gauge port for a recirc but the gauge port is at the reg outlet pressure and if using a orifice restriction i dont see why not for a return line. Anything down stream of the reg prevents the fuel press to carb from "dead head" and electric pumps or the carb needle and seat dont like that. Your tank return line should be very close to that reg location and a short piece of flex line should work very well. Your '78 should have a return line to the tank unless its been removed. Thats a clever reg mount on the fuel pump casting pad.
My self i like the return to start as close to the carb as possible and of course use a tiny orifice restriction (0.040'-0.050"). I think i see a holley carb in your pix and a possible location is the opposite side inlet (drivers side) to the fuel bowl. That should already be threaded but u will need another mile of fuel line to go around carb and down to the tank return line (well maybe only a couple feet) but attachment/installation could be fast and simple.
Hope this helps even if a little slow to respond.
Thanks for the reply. I'm going to go with replacing the rear 90* with a "T" at the rear of the carb line then down to AN4 with steel braided to the 5/16 return line. I have all the fittings and line. I just need a .060 orfice as I seen in the return line that Lars set up in another thread. Just need to find a source for the orfice.
From: Las Vegas - Just stop perpetuating myths please.
Not sure how or what u will attach/install the orifice. I used a brass screw or plug and drilled a hole in the center of it. I had to tap/thread the inside of the brass Tee i threaded it into first. What the orifice does is reduce the flow and minimizes the vapor produced when it returns to the tank. But any small amount of flow will keep cooler fuel into the carb and stabilize the regulator output press.
Not sure how or what u will attach/install the orifice. I used a brass screw or plug and drilled a hole in the center of it. I had to tap/thread the inside of the brass Tee i threaded it into first. What the orifice does is reduce the flow and minimizes the vapor produced when it returns to the tank. But any small amount of flow will keep cooler fuel into the carb and stabilize the regulator output press.
Great idea! Thanks. I think I can do that in the AN6 "T" fitting then followed by the -6 to -4 reducer, 180* AN 4 hose fitting. -4 line to the return hard line.
Not sure how or what u will attach/install the orifice. I used a brass screw or plug and drilled a hole in the center of it. I had to tap/thread the inside of the brass Tee i threaded it into first. What the orifice does is reduce the flow and minimizes the vapor produced when it returns to the tank. But any small amount of flow will keep cooler fuel into the carb and stabilize the regulator output press.
For a quick fix....making your own orifice is the way to go....
start with a .040 drill-----it's easier to go larger if necessary to obtain the correct pressure than to drill too large of a orifice on the first try.
For a quick fix....making your own orifice is the way to go....
start with a .040 drill-----it's easier to go larger if necessary to obtain the correct pressure than to drill too large of a orifice on the first try.
i also used a .040 dia. orifice going back to tank worked perfect.
Fuel return line. Lars?
For a quick fix....making your own orifice is the way to go....
