Fuel volume drop after regulator?
 

I did the timed fuel test and found 1 gal. @ 32 seconds at the regulator and a tick over 50 seconds at the carb. Agreed this is not adequate for at carb volume. My question is. What is acceptable volume drop after the regulator at the carb? This is with a holley blue pump and holley regulator. Yeah I know time to update! The application here is SBC stocker with Qjet.

Re: Fuel volume drop after regulator?
 

25 or less, Doug. I had a Holley black pump and it would not have enough volume, to keep a quadrajet full, especially at launch. I switched to a Magnafuel 275 and reg., and it made a big difference. Dont use a small fuel pressure guage, a full sized one will be more honest. Run at least a -8 or even a -10 line.

Re: Fuel volume drop after regulator?
 

I too just had a blue pump crap out and just replaced it with another blue pump. All the while I was jerking around with it I could not help but wonder is this really worth it vs. a nice mechanical pump??? Really, how much ET could I possibly lose given the GPM was adequate with a mechanical and 1/2 alum. line and get rid of all the braided crap. My guess is not enough to offset the 1000$ in a fuel system.

Re: Fuel volume drop after regulator?
 

Those Holley Regulators are a joke.
Less than a .250 hole with a .090 pin passing through the hole... not near enough area to pass a decent volume of fuel. I would bet the area of the jets in you Q-Jet are more than twice the actual area available in those Holley Regs...Size the line based on N/S volume and Regulator volume.
OH! did you notice those nice big fittings on that blue pump and that little feed hole inside....never measured one, all it took was a look, but 1/4 in might be near the size...

Re: Fuel volume drop after regulator?
 

The holley pumps have been real reliable over the years in my car. You will need 2 of them to supply enough fuel for a Q-jet. I run 2 holley blue pumps and an Aerospace 2 port regulator. I will replace this system with a single Aeromotive, Magnafuel or similar pump when needed.

Re: Fuel volume drop after regulator?
 

For What It's Worth.....

Just replaced the fuel system on my D/SA with a complete Aeromotive system and found a .10 of a second that had been hiding. Most noticably in the back half, car now pulls HARD the last 660.
I replaced an OLD (antique?) Mallory pump & regulator and the 1/2" lines the fuel was running through. I now have 2 -8 lines running from the cell to the pump, with a -10 line running forward to the regulator & then the carb.
Even got a call from Aeromotive about a month after the installation asking me to send the regulator back because there MIGHT be a problem with it, swapped it out @ no charge.
Still tinkering with it, heck, there might be some more...... From what I've learned, that Q-jet needs alot of fuel getting to it.

Quality products, GREAT customer service!

Unk

Re: Fuel volume drop after regulator?
 

Aeromotive is the best way to run a Q-jet and a good investment for your car. It costs less to do it right than to do it twice.

Re: Fuel volume drop after regulator?
 

Which Areomotive regulator are you using? most only show a #6 line to the carb. one of my buddies bought one and we had to drill and tap the regulator to install a #8 fitting. the carb was starving for fuel with the #6. other than that the reg works good.

Re: Fuel volume drop after regulator?
 

Also remember only 6 to 6 1/2 lbs. of pressure to push the volume. Just like a garden hose the more pressure the less volume.

Re: Fuel volume drop after regulator?
 

It escapes me how people have to put a $1,000 fuel system on a Q-jet car when they could hook a 3" hose to a tanker truck and still have a .149 needle and seat to pass it through. My auto shop teacher in high school had a 68 camaro big block 427 and Q-jet with a Holley blue pump and Holley reg. and went 10.28 but a 305 Q-jet combo needs a nitro pump on it ??? It seems more attention to mounting and plumbing is what is needed. Just my opinion. Like belly buttons ..... everybody got one!