Tripple fuel lines options

[ezzzzzzz]

There are so many ways to plumb a set of tripples or so it seems. As it is merely just one more carb added why does fuel supply become complicated. My present setup (untested) is as follows...

tank - RX7 low pressure electric pump - regulator (dial type) - STOCK metal fuel lines used for SU's - two lines feeding T's between each carb - factory return in metal fuel line - tank

My theory is that you need to supply enough fuel to keep the bowls full at WOT, low enough pressure to allow the floats to control fuel bowl level at idle and not blow the needles off the seats (causing flooding/rich idle) and a restricted return to keep the pressure to the carbs around 3.5 -4 psi.

Has anyone ever tried this arrangement? Comments?

[SER240Z]

Sounds like almost the same setup as mine, except;

Holley red pump, holley regulator, two lines to T's between carbs, number 3 carb has line plumbed to stock return line. I'm running about 4psi on triple 44 Solexs. Runs fine, I have a little bit of bogging on the bottom end, but I think that is just tuning. I could probably use a cam also. I think carb size will also have a big effect on how well it runs along with motor and head work.

Scott

[240ZX]

Since neither of you mentioned filters.....It's highly recommended to use filters in a fuel system.....one pickup filter between the tank and pump and one filter (fine element) just before the regulator.

[SER240Z]

Sorry, forgot to mention that. I've got a filter between the tank and the pump, and one filter on each line running into the T's.

Scott

[jmortensen]

There are so many ways to plumb a set of tripples or so it seems. As it is merely just one more carb added why does fuel supply become complicated. My present setup (untested) is as follows...

tank - RX7 low pressure electric pump - regulator (dial type) - STOCK metal fuel lines used for SU's - two lines feeding T's between each carb - factory return in metal fuel line - tank

My theory is that you need to supply enough fuel to keep the bowls full at WOT, low enough pressure to allow the floats to control fuel bowl level at idle and not blow the needles off the seats (causing flooding/rich idle) and a restricted return to keep the pressure to the carbs around 3.5 -4 psi.

Has anyone ever tried this arrangement? Comments?

The only issue I have with this is the dial type regulator and it's placement. If you're running a return line than the return line restricted orifice is the "pressure regulator". I don't know if that would cause issues or not and it might work just as you stated.

I would figure that it would be prefereable to have the regulator after the carbs and before the return line, and then it would need to be the other style that affects the fuel pressure before the regulator not after it.

[ezzzzzzz]

I forgot the filter too! As for the regulator, My vehicle came with three dial-types, One after the filter and the two others inline with each SU. I dialed down the pressure to 2.5 psi (no gauge though) on all three and had no problem at WOT and high rpm runs. Now there is only the one regulator left. I don't know if it is of any worth to run it but if flooding occured at idle this would be as quick an adjustment as a regulator down line form the carbs. I already have it too. I will install a gauge on the last carb T fuel fitting to monitor the pressure out of curiousity.