There is one advantage to welding/brazing a return port at the tank, and that is to thoroughly remix the circulated fuel with the fuel still in the tank. Fuel that is delivered to the rails but not consumed by the injectors normally returns to the tank heated by its exposure to the hot engine compartment. This becomes just as big of an issue as it was with carbureted engines after shutting the engine off and letting the fuel sit unmoving in the lines (ie: hard starting 5-10 minutes later). That's why a proper EFI system powers the pump for 0.5-1.0+ seconds to purge and pressurize the rails when initially turning the ignition key to the Run position. Using a tee would result in reduced fuel cooling efficiency, but you'd have to experiment to determine if it is really an issue or not. Any vapourized fuel would normally be released as bubbles back into the tank when using a dedicated return port, but using a tee might not work as well, especially with a pump nearby that doesn't particularly care whether it ingests liquid or vapourized fuel.
CB did it because it was simpler, not necessarily better. I ran the CB tee initially, but just brazed a small port near the filler port on my otherwise stock tank later on. If you don't want to braze/weld, a "mechanical" version could be utilized using bulkhead fittings and the proper o-rings made by someone like Aeroquip, Russell, Earl's, etc. _______________________________________________ vintagvw site list [email protected] http://lists.sjsu.edu/mailman/listinfo/vintagvw
