As some of you may know I am building a 383 stroked to a 450 with a 6-71 up top. I am running dual 4 bbl carbs, boost referenced. I am running dual fuel pumps. My question is, do I need boost referenced regulators? And if I do, do I need a return line for the pump? Pump is a 150 gph rating at 6psi. Running two -8an lines from fuel tank to each pump. From there, I'm running 3/8" line to the regulators. Option of running -6an lines to regulators. Help before I waste my money! Thanks guys.

 

IS this going to be a street car. Just asking before I throw my 2 cent in. So far I do not like any of what your doing with the fuel system.....

 

if what i have read is right. if the carbs are above the blower, feed fuel to them just like you had no blower. check out the site http://www.paxtonauto.com/ they show how to do it when you blow through a carb. the fuel pressure has to be made higher by the amount of the blower pressure.

 

Looks to me like he is going old school Moe.... Roots type 6-71 blower....
Blow through's a different beast.....

 

a guy i know at the flea market has a paxton blower. it has some of the parts but is missing the carb hat, and some other stuff. at first i thought it was a 1957 Ford unit. but that one has fins all over it. this one doesnt. seams to be lots of info on in Ford blower on the inter net. my friend has $1000. on his unit.

 

I just wanted to confirm if I need a boost referenced regulator, and if I need a return line. Will be running 6psi after the reg.

 

Yes this will be my street car.

 

OK...Here's my 2 cents... No Return Needed.....Only need 1 pump....
1 Good Pump.... Barry Grant....Weldon.....Aeromotive... Or something along those lines.
2 Good Filter....
3 #8 line from tank to Reg......
4 #6 line to carb / carbs
5 Good Reg....
This should be more than enough with room to spare for what your going to use it for.

Note: in place of the #8 line...You could run #10... But that a lot of Money.

Good Luck...Keep us posted....

 

Racerhogg,

So what your sayings that a second pump is overkill? I have double pampers for carbs, so off that 6an line to the carbs I am splitting 4 ways. That is enough for both carbs? I have already purchased two Holley 12-150 fuel pumps, but I guess I can keep a spare one. So 8an line from tank to pump (which has a 3/8" inlet and outlet), then keep 8an line to boost referenced fuel regulator, then 6an to both double pumper carbs? This will be enough fuel? What fuel pressure should I be running because all lost referenced regulators seem to be in the area of 50psi. Or do I need a regular regulator and then rot after a boost referenced one? I am so confused about this. Racerhogg, your a genius, and I appreciate yours and everyone else's help.

 

I was going to run one pump to each carb. Then my fuel lines can be smaller. What is a return line for anyway?

 

Should not need boost referencing on a draw through system:http://www.automotiveu.com/BlowerTuning.htm

I like the idea of a return line, if nothing more than to keep the fuel cool.

 

3/8 is 6an....
You can run #8 From the tank to the filter
You can run #8 From the filter to the Pump
Then you can get away with #6 up to the Reg
Then you can Run #6 from the reg. out to the carbs.
You will gain a little more consistent pressure. You just loose a little Flow..

This might help you understand a part of the restriction....
http://www.gre6.com/ansize

Second Pump is over Kill in My opinion for what your doing....
The system With the #8 and #6 will handle 2-1250 Dominators And I'm sure your not going that big for a street blown Motor car... I wouldnt go over 2-650's
Boost Ref. Reg... Dont need it...Send it back...
7-8 Psi Depending on What Needle and seats you run in the carbs....
If you havent bought the carbs yet... It better to buy the carbs set up for a blown motor... It just makes it a little easyer on you than trying to tune from scratch.... But if you already got them... Well it is what it will be....
For the Reg... http://aeromotiveinc.com/products-pa...-06-regulator/

 

Yes. I have dual 670cfm Holley boost referenced carbs. My thought with the return line as to keep the fuel as cool as possible. Thanks again guys!

 

Dont get me wrong... I'm Not Opposed to the return system.....

 

I just wasn't sure if that was the only advantage or purpose for return line.

 

Hummm...No...
If you where going to run an Injector hat induction system, you would have to have a return back to the tank.

 

You can use a new model corvette fuel filter for this application too. It has a return port on the filter that cycles the fuel back into the stream. So you return to the filter and that's it. You can put the filter where ever you like and it will cut down on plumbing and gives you an OTC filter to make replacement easy. That may give you the cooling bonus without all the hassle of going all the way to the tank. Just a thought. Good luck!