I have heard that a fuel recirc. line can be used on the driver's side fuel bowl inlets on a 3310 if they are tapped for fittings to help dealing with hot weather conditions. Any one tried this?
fuel return line
- Thread starter old guys rule
- Start date
PurpleBeeper
Well-Known Member
I have not tried it, but it sounds reasonable. I plan to install vapor return lines soon just using fuel filters with an extra small nipple. If that doesn't work, I will give the 440+6 vapor canister a try.
sputnik 440
Capt Jim
I have been told that you can run a return line fro any connection between the fuel pump and the carb, and run it to the fuel line coming out of the tank. Not on the tank, but somewhere on the fuel line following the tank. The closer to the tank, the better. Question.....will that eliminate the vapor lock from the fuel boiling on my 440? Or, do l have to go to the tank?
383coronet
Member
I would say go to the tank like factory did.
sputnik 440
Capt Jim
10-4, I guess that means dropping the tank and changing out the sender unit/float. First, I have to run out the full tank of petro I put in there. Shouldn't take long at 6.5 miles per gallon. Thanks for the input, just what I guess I knew the answer to all along.
69hemibeep
Well-Known Member
Tapping the fuel lines sounds like allot of work when a fuel filter will do it. Ive done a couple vehicles with the filter and 1/4" return to the tank.
vintage chromoly
Well-Known Member
Get the proper filter / vapor separator.
It has a 1/4” return port on it
It has a 1/4” return port on it
I'm looking to run a fuel return line from the dr side of the fuel bowls to keep a cool supply of fuel circulating from the tank, not a vapor return. My carb has dominator bowls (already tapped) I ran a 1/2 inch fuel line from the tank to the carb and plan to use the original 5/16 line as the return. My concern is if this will destabilise the float adjmnt.
69hemibeep
Well-Known Member
True about the filter, I just use 1/4 return its easier to work with than larger tubing
sputnik 440
Capt Jim
I have a 3/8 fuel line with a 100mm in-line filter between tank and pump I then com out of pump with 3/8 to a 40mm mesh Holly inline filter just before the Holley 850 DP. The only vapor separator I have found is 5/16. Will this reduction from pump to separator and back to 3/8 mess up my pressure at the carb and starve the 440?
451Mopar
Well-Known Member
I think that would work great. keep fuel flowing all the way to (and past) the needle and seat. Just need to size the return restriction so fuel pressure does not drop at full load.
sputnik 440
Capt Jim
Thanks, 451.......So , the thirst of these 850s, nor the fuel pressure (I need right around 6.5 - 7 psi) will be effected by the pressure drop from the separator (5/16) to the 40 mm mesh with a 3/8" line. Correct?
Another question. How does the filter/separator/return line, located aft of the pump, keep the fuel from "Boiling" out of the carbs and ultimately giving me a vapor lock? If the carb gets too hot, won't it still "boil-over" and become impossible to start unless you go to WOT. I hate the wide open throttle part. Those rpm with no load sounds like trouble. Side note, I have wrapped the fuel line, the 40mm mesh Holley with insulation in order to keep things a bit cooler. I am going to wrap my headers with fiberglass tape. I may even open the two GTX hood scoops and put hole in the hood to get air to the engine, or expell hot air right when the car is turned off. Any ideas other than that? I hate to "ruin" a good hood, but if the sacrifice is for the greater good, in hot weather, it may be worth it. Opinions?
Another question. How does the filter/separator/return line, located aft of the pump, keep the fuel from "Boiling" out of the carbs and ultimately giving me a vapor lock? If the carb gets too hot, won't it still "boil-over" and become impossible to start unless you go to WOT. I hate the wide open throttle part. Those rpm with no load sounds like trouble. Side note, I have wrapped the fuel line, the 40mm mesh Holley with insulation in order to keep things a bit cooler. I am going to wrap my headers with fiberglass tape. I may even open the two GTX hood scoops and put hole in the hood to get air to the engine, or expell hot air right when the car is turned off. Any ideas other than that? I hate to "ruin" a good hood, but if the sacrifice is for the greater good, in hot weather, it may be worth it. Opinions?
How to determine the FUEL return line restriction?
sputnik 440
Capt Jim
I read where the hole is no greater than a paper clip. Drill it open if you need more. I have not done it, but that was the instructions I read on a search in another blog. Affirm this with someone else.
383coronet
Member
You can get the factory style filter with 1/4" vapor line on it from rock auto.On my 69 coronet you can change sender w/o dropping tank.
383coronet
Member
Vapor lock happens at the pump.If you want to keep carb cooler block off heat riser and or put a insulating spacer under carb.
I went with the block off and 1/2 inch phenolic spacer. Helped but still heat soaks. Specified the return set up on upcoming efi in order to better cool the fuel supply.
sputnik 440
Capt Jim
Ya, I already did the spacer and the block off. You cant touch the fuel line and filter going into the carb when it is run on a hot day. I have got to get some air into the beast and block off the heat coming from the 2" headers. I really believe that they are my problem and some bad *** gass I bought. Started pinging the minute I filled up with 93 non ethanol. I hear that the vaporizing won't happen if you run racing gas. Any experience?
I dont run race gas. Road car. Driver. All gas here is ethanol laced. It boils at 174. So even a good running motor and cooling system creeping to 190 or so has issues.
the return line orifice the size of a paperclip is for a VAPOR return. I'm looking at installing a FUEL return line. they seem to be getting confused. appreciate your help one and all.
Similar threads
