whats the ideal Fuel line setup for triple carbs?

[240znz]

The NISSAN factory triple fuel rail does not have a return.

I have run new lines anyway but will just block off the return at the frame rail so that I can run the original carbs if I get sick of the 44phh's...fat chance.

[preith]

This may not be applicable but I've been running setup #3 on my road racer for 4 years now, with a return line from the fuel block and a Holley bypass regulator, Carter comp pump (100GPH), 1/2" ID fuel lines (8AN hose). I originally had twin solid-state pumps and a 6AN feed line but the fuel pressure dropped off at 7k. The return line is easier on the pump too.

[five&dime]

I am still lost as to where I plumb my return from based on my previous post^ Anyone???

[preith]

I am still lost as to where I plumb my return from based on my previous post^ Anyone???

With your current setup I don't see how it would be possible. This will probably open a can of worms, but IMO a return line should not be used with a inlet style pressure regulator but rather a bypass style - after the carbies liks an FI setup. It creates a potential for fuel starvation at high rpms because the pump then needs to supply enough fuel for both the carbs and the return line to maintain pressure.

[five&dime]

Makes sense. So what would you recommend to resolve this and run a return? Could I replace my regulator in order to run a return line?

[overdrivex]

the guy i bought them from said i should run setup #1 with a lower pressure fuel pump and a FPR that can be set to 3psi. some sources ive found that use setup #1 say the same thing. i tried sourcing a 3rd T fuel bonjo for setup #2 with no luck . i email dellorto in UK and its gonna cost $80shipped 7-21days just for that one bonjo. that's almost half the price of one used carb. i also said i wanted to run setup #2 in the email and said it would be ideal setup. they also recommended setup#1 with a low pressure pump 3-7psi and a fpr adjustable to 3psi. i guess thats why the setup only comes with two T's cause this how they expect you to run them.

i ask my uncle which use to be a mechanic he said a fuel injection fuel pump would put out too much pressure for a carburetor setup and would put to much stress on fuel system/line. he also said return line is important because it keeps fuel moving and doesnt allow the fuel to get to hot when it pools in the reservoir.

so now im considering running setup one to save 80bux and in hopes to not have to wait 7-21 business days just to get the car running. and on top of that even the manufacture recommends setup #1

just to be clear its a throw between ideal setup and recommended setup from manufacture..

Edited April 7, 2009 by overdrivex

[overdrivex]

since i wont have a return would this FPR work for me?

http://cgi.ebay.com/ebaymotors/Megan-Racing-Universal-Fuel-Pressure-Regulator-Blue_W0QQcmdZViewItemQQ_trksidZp4634Q2ec0Q2em14Q2el1262QQhashZitem310133827524QQitemZ310133827524QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

it say feul injection only but seems like all of the FPR i find say FI only.

[bradyzq]

Nope, that won't work. I doubt that you could get accurate adjustability at the low pressure you need.

Also, that is for a return type system.

[bradyzq]

This should work:

http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY-12-804&N=700+115&autoview=sku

[overdrivex]

This should work:

http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY-12-804&N=700+115&autoview=sku

you know i forgot all about summitracing thnx

[overdrivex]

i wanted to run a pressure gauge in line since the holly doesnt have one already. i gues the best place to put the guage would be right before the last carb inline to insure that im getting 3psi to the last carb too?

Edited April 8, 2009 by overdrivex

[Carl Beck]

This should work:

http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY-12-804&N=700+115&autoview=sku

Some things don't change - thank goodness.

That is the same Fuel Pressure Regulator that BRE ran on the Baja Z in 1973. The original was still on the car, and you can still buy rebuild kits for it. Both the High Pressure and Low Pressure versions are identical in construction - the only difference is the spring used. The rebuild kit comes with both springs and can be used for both High and Low pressure regulators.

Just to be safe, I rebuilt mine - put a fuel pressure gauge on it and it is right on the money.

FWIW,

Carl B.