Ideal Fuel Pressure?

Author Topic: Ideal Fuel Pressure?  (Read 3821 times)

Offline the Wizard

  • Business Manager
  • Sr. Member
  • *****
  • Posts: 1275
  • Imagination is more important than Knowledge - Albert Einstein
Ideal Fuel Pressure?
« on: December 01, 2001 - 05:56:05 PM »
So what's the ideal fuel pressure, as adjusted by a regulator, in the fuel line before the carb?  And does it vary for different engine sizes?
« Last Edit: December 31, 1969 - 07:00:00 PM by 1023595200 »




Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: Ideal Fuel Pressure?
« Reply #1 on: December 01, 2001 - 06:05:28 PM »
Ideal pressure is 6psi with the regulator as near to the carbs as possible & no it doesn`t vary for CI the float will not be able to shut off the fuel flow above 7 psi & it will flood ;)
« Last Edit: December 31, 1969 - 07:00:00 PM by 1023595200 »

Challenger - You`ll wish You Hadn`t

Offline the Wizard

  • Business Manager
  • Sr. Member
  • *****
  • Posts: 1275
  • Imagination is more important than Knowledge - Albert Einstein
Re: Ideal Fuel Pressure?
« Reply #2 on: December 01, 2001 - 06:15:37 PM »
Neil,

So now you have to do double duty...on two boards...haha!

With regard to fuel pressure....is it important because it is an indicater of fuel flow (high pressure = high flow)?  In other words, if it were easy to measure flow....is that what we would measure?
« Last Edit: December 31, 1969 - 07:00:00 PM by 1023595200 »

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: Ideal Fuel Pressure?
« Reply #3 on: December 01, 2001 - 06:36:35 PM »
How did you get 5 stars already ... you must be a guru :owher can I read all of your 1005 posts I can`t find them here?????????? ???

Pressure will help prevent vapour lock but doesn`t really affect flow as much the dia of the line will affect flow more ,I`m sure there is a formula for this but I haven`t got my mech engineering yet!! eg a 3/8" line at 6 psi should outflow a 1/4 " line at 14 psi but this is why you want to run the regulator as close to the carb as possible & run 14 psi up to the regulator to get the max efficiency from the line.I would be more concerned with measuring volume /min or sec. The fuel pumps available are remarkably small , the Holley Blue is 110 Gal / Hr or 1.83 gal/ min or .3 gal in 10 sec or just over 1 qt in a 1/4 mile pass at the strip my Duster used 1/2 gal / 11 sec pass.
 This should be a challenge trying to keep up with 2 boards !! I was telling Chargerbill that it was getting difficult to keep up with all the posts on the Charger site  ::)  Actually I really enjoy helping I have too much time to kill with the 8 mon winters anyway & cannot work on my car in - 20*

Challenger - You`ll wish You Hadn`t

Offline 69ChargerRT

  • Administrator
  • Resident
  • *****
  • Posts: 2622
  • Its the car, right? Chicks love the car. - Batman
    • Daisy - My 1969 Dodge Charger R/T
Re: Ideal Fuel Pressure?
« Reply #4 on: December 01, 2001 - 06:40:16 PM »
Sr asked to be bumped up to a 1000 posts as an honorary status kind of deal.  He threatened to stop working on the charger, and though im not sure if i would be as disappointed as he would be without being able to work on the car, i thought it better not to call his bluff.
« Last Edit: December 31, 1969 - 07:00:00 PM by 1023595200 »

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: Ideal Fuel Pressure?
« Reply #5 on: December 01, 2001 - 06:42:41 PM »
Well at least he is ahead of cudaken for a day or two!!!
« Last Edit: December 31, 1969 - 07:00:00 PM by 1023595200 »

Challenger - You`ll wish You Hadn`t

Offline 69ChargerRT

  • Administrator
  • Resident
  • *****
  • Posts: 2622
  • Its the car, right? Chicks love the car. - Batman
    • Daisy - My 1969 Dodge Charger R/T
Re: Ideal Fuel Pressure?
« Reply #6 on: December 01, 2001 - 06:47:41 PM »
so true..
however, in recognizing all your vast knowledge, and all the tremedous help that sr and i could not have done without (and all that you will continue to give us) ive made you the boards Official Tech Expert.
« Last Edit: December 31, 1969 - 07:00:00 PM by 1023595200 »

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: Ideal Fuel Pressure?
« Reply #7 on: December 01, 2001 - 06:52:26 PM »
UH UMMM well Thanks I will try to live up to the billing to the best of my abilities, this may however mean that I will have too unearth some of my reference sources,OH Boy ,instead of going from memory...

Challenger - You`ll wish You Hadn`t

Offline 69ChargerRT

  • Administrator
  • Resident
  • *****
  • Posts: 2622
  • Its the car, right? Chicks love the car. - Batman
    • Daisy - My 1969 Dodge Charger R/T
Re: Ideal Fuel Pressure?
« Reply #8 on: December 01, 2001 - 06:54:39 PM »
im sure youll do fine, unless of course you dont want that kind of recognition
« Last Edit: December 31, 1969 - 07:00:00 PM by 1023595200 »

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: Ideal Fuel Pressure?
« Reply #9 on: December 01, 2001 - 07:02:03 PM »
I don`t mind ..,.Glad to help :D ;)
« Last Edit: December 31, 1969 - 07:00:00 PM by 1023595200 »

Challenger - You`ll wish You Hadn`t

Offline the Wizard

  • Business Manager
  • Sr. Member
  • *****
  • Posts: 1275
  • Imagination is more important than Knowledge - Albert Einstein
Re: Ideal Fuel Pressure?
« Reply #10 on: December 09, 2001 - 04:38:45 PM »
Chryco,  

So why is it so important for the regulater to be close to the carbs?  I wouldn't think there would be much pressure drop in the line...and if so could still be adjusted for at the regulater, even if it is far away.  What's up?
« Last Edit: December 31, 1969 - 07:00:00 PM by 1023595200 »

Offline Chryco Psycho

  • Administrator
  • C-C.com Guru
  • *****
  • Posts: 36620
  • 70 Challenger R/T SE 70 tube Chassis Cuda now sold
Re: Ideal Fuel Pressure?
« Reply #11 on: December 09, 2001 - 08:49:22 PM »
 You can run 15+lbs as far as possible which helps flow & helps prevent Vapor lock near heat, hummm where do you suppose the most heat is ??  
« Last Edit: December 31, 1969 - 07:00:00 PM by 1023595200 »

Challenger - You`ll wish You Hadn`t

Offline Dark Horse

  • Jr. Member
  • **
  • Posts: 327
  • 70 Cuda ,69Mach 1,70 Charger RT/SE
Re: Ideal Fuel Pressure?
« Reply #12 on: January 14, 2002 - 10:28:21 PM »
im no expert, but 6psi is ideal. adjust to six then open the car at high end and watch/listen how the car is running, if it sounds like its dying and floats are adjusted  right ,increase the pressure slightly and go again. Again not an expert.If im off someone let me know, like most i learn everytime i step into the garage.
« Last Edit: December 31, 1969 - 07:00:00 PM by 1023595200 »

When you see the Dark Horse...take heed
hell is coming to breakfast......