Fuel Volume Problem

[lvrpool32]

I am running 4 Dellorto's (48MM) on my 396 small block and I seem to have an issue with fuel starvation. Not with the jetting, my AF is spot on, what happens is if I drive it around and get on it a little it acts like it has run out of fuel....i leave it sit and crank it, 30 seonds later is starts and runs great. So I am guessing I'm draining the fuel bowl.
I have 6AN lines from the tank, to a FRAM fuel filter, to the holley pump (blue) - 6AN line to a regulator then a fine filter, then feeding the carbs in series (i.e. one line going to #1 , then to #2 then to # 3 then ends at #4.)
I have a feeling that I am confusing the low pressure requirements of these carbs (3 psi max) with the need for volume, basically I am not feeding enoguh fuel in to keep up with demand.
So my plan is to run a 8AN line from the filter, to the pump to the regulator, but then I have questions....
1) would it be better to run two regulators - use a fuel log and have two regulators mounted and then feed the 6AN line to just a pair of carbs.
2) would it be better to run 1 regulator, but run an 8AN into it and then an 8AN out of it to a Y then 6 AN from there.
Are banjo fittings bad for flow??? as bascially each carb has one, was wondering if I would be better of running individual lines to each carb with a 90 degree hose end.

Thoughts?
Nick

[anthonys 69]

When it acts like it running out of fuel have you tried leaving the engine running and checking fuel pressure and revving the motor and watching fuel pressure at the same time see if you still has 3 psi if so you probable have fuel [ not sure but I thought 8 psi was Max for carb set up]. does you fuel pressure regulator have a vacuum port where you can set the fuel pressure say at 6-8 psi motor running vacuum line off. After reconnecting and when the engine starts and applies vacuum it will lower the pressure to around 3 psi , on hard acceleration when needed will there be more fuel for the demand.
We had a 69 chevy impala in the shop with similar problem turned out the customers wife barrowed the car told no one and back the car over a curb and put a nasty bed in the exhaust tail pipe the back pressure killed the motors power and it took a few mile for the pressure to build up too. Seen this with cars with catalytic converters too.

[Randy67]

If you are running the regulator that came with the Blue pump, I would run two of them. I ran into this on my car, one of the Holley regulators couldn't keep up with 2 carbs (holley 650s on crossram), fuel pressure dropped on top end. Even Holley recommends two regulators for dual (or more) carbs, unless you step up to one of the better regulators out there.

[lvrpool32]

I have searched everywhere for different regulators, but they all start at 4 or 5psi, which is too much for the Dellorto/Weber downdraft style carbs. (I did find a 3psi from a company called Fuelab, but its pretty expensinve and I have never heard of them!!)
So I am thinking about getting a second regulator...feed 8AN into those and then 6AN from there to the carbs.

[anthonys 69]

Sorry I did some checking and the advice I gave would be ok for a Holley or Rochester but not for a Weber or dellorto, interesting set up you have. I’ll be following this thread to learn. if you can post a pic or two. Id appreciate it Thanks

fuel pressure reg with filter
http://www.dellorto.com/merchandise/...rtsectionID=18

[Randy67]

Holley does offer a regulator that goes from 1-4 psi, http://holley.com/12-804.asp but I would still run two of them for adequate fuel flow. Other than that not many regulators go that low.