Results 1 to 14 of 14
Thread: Fuel pressure for blown sbc?
-
06-29-2010 #1
Full Blown G-Machiner
- Join Date
- Dec 2005
- Location
- Coolidge, GA
- Posts
- 988
Fuel pressure for blown sbc?
I've got shop beater running. What kind of fuel pressure should I be running. Built motor at 12 psi
-
06-29-2010 #2
Registered User
- Join Date
- Mar 2006
- Posts
- 136
I know on our blown 351 clevlend we were running 11 psi fuel pressure, but it was only running 8 psi of boost.
-
06-30-2010 #3
Full Blown G-Machiner
- Join Date
- Dec 2005
- Location
- Coolidge, GA
- Posts
- 988
I'm planning 16 psi. I think I heard 1.5lb per psi
-
06-30-2010 #4
Registered User
- Join Date
- Aug 2004
- Location
- CHICAGO SUBURBS
- Posts
- 761
You will need a boost ref. fuel regulator. It will be set at base fuel pressure and rise 1 to 1 with boost. With low boost fuel injection the pressure can stay static and tune around it. Hope this helps.
Frank B. 1968 Camaro 355 Procharged 6 speed. 1983 V8 S10. 1984 Monte Carlo Magnusen Charged iron 6.0. Plus a few other junkers!
-
06-30-2010 #5
Full Blown G-Machiner
- Join Date
- Dec 2005
- Location
- Coolidge, GA
- Posts
- 988
yeah thats what I understand to setup as. But what should I be looking at for a base and then at full.
-
07-01-2010 #6
Registered User
- Join Date
- Aug 2004
- Location
- CHICAGO SUBURBS
- Posts
- 761
The base pressure is set just like normal. Around 6-7 for a carb, and usually around 58-60 for fuel injection.
Frank B. 1968 Camaro 355 Procharged 6 speed. 1983 V8 S10. 1984 Monte Carlo Magnusen Charged iron 6.0. Plus a few other junkers!
-
07-01-2010 #7
Full Blown G-Machiner
- Join Date
- Dec 2005
- Location
- Coolidge, GA
- Posts
- 988
I'm learning everyday! First blower car so things are a little new to me!
-
07-01-2010 #8
Registered User
- Join Date
- Jan 2005
- Location
- Boonville, Missouri
- Posts
- 924
Hilrod is correct on the fuel pressure and boost referenced regulator.
-
07-01-2010 #9
Full Blown G-Machiner
- Join Date
- Dec 2005
- Location
- Coolidge, GA
- Posts
- 988
this is the reg I am using!! SO I just need to set the pressure at 6-7 psi at idle and the reg will bump it up from there>
http://aeromotiveinc.com/products-pa...ass-regulator/Last edited by fletcherscustoms; 07-01-2010 at 07:31 AM.
-
07-02-2010 #10
Registered User
- Join Date
- Aug 2004
- Location
- CHICAGO SUBURBS
- Posts
- 761
Yep. Sounds good.
Frank B. 1968 Camaro 355 Procharged 6 speed. 1983 V8 S10. 1984 Monte Carlo Magnusen Charged iron 6.0. Plus a few other junkers!
-
07-08-2010 #11
-Moderator/Sponsor-
- Join Date
- Apr 2001
- Location
- The City of Fountains
- Posts
- 16,125
Just to clarify, some EFI systems operate at 43.5psi, the later LSx engines operate at 58 psi. With aftermarket systems it does not matter. You just have to choose your injectors based on the pressure that you will be running. Make sure you are aware at what pressure the injectors are rated. Also be aware of the fuel pump output at various pressures that you plan to run.
Andrew1970 GTO Version 3.0
1967 Cougar build
GM High-Tech Performance feature
My YouTube Channel Please Subscribe!
Instagram @dr__efi
I deliver what EFI promises.
Remote Holley EFI tuning.
Please get in touch if I can be of service.
"You were the gun, your voice was the trigger, your bravery was the barrel, your eyes were the bullets." ~ Her
-
07-08-2010 #12
Registered User
- Join Date
- Aug 2004
- Location
- Rustburg, Virginia
- Posts
- 3,436
For a carb...(at idle)needles and seats can't handle more than 6-8psi of fuel pressure before they allow fuel to over flow the bowls and flood the engine with raw gas. EFI is a different animal altogether, as Andrew stated.
1970 RS/SS350 139K on the clock:
89 TPI motor w/ 1pc rear seal coupled to a Viper T56 via Mcleod's modular bellhousing w/ hydraulic T/O bearing from the Viper, 12 bolt rear w/ 3.73 gearing, SC&C upper control arms, factory lowers with Delalums, C5 brakes at all four corners, Front Wheels 17x8's with Sumi 255/40/17 and Rear Wheels 17x9's with Sumi 275/40/17.
Brief description of the work done so far can be found here: http://www.nastyz28.com/forum/showthread.php?t=112454
-
07-09-2010 #13
Registered User
- Join Date
- Dec 2008
- Location
- Columbus, IN
- Posts
- 131
John is correct. I run 7 psi base on my blow thru with holley style carb. Connect the small port on top the regulator to your carb hat/bonnet. fuel pressure rises 1:1 with boost.
'66 Mustang
'67 FireBird https://www.pro-touring.com/forum/sh...light=firebird
'68 Barracuda
'69 Mustang Mach 1
'97 Mustang Cobra
'04 Mustang Cobra
-
07-19-2010 #14
Registered User
- Join Date
- Mar 2008
- Location
- UK London
- Posts
- 527
Yep, 7psi on my carb even with a ton of boost. The fuel reg will add psi as required. The trick is the correct size feed, return, rails, pump and pump location. This is all related to power goal however you can never have too much. Cost is a factor as a 2000hp capable system will work on a 500hp set up. If it runs out of fuel pressure under boost it can burn a hole in a piston etc.
Check out the Areomotive or Magnaflow sites for some suggested set ups applicable to various horse power levels.
As a guide
stock fuel lines to approx 600hp Electric pump/s
-10AN feed/return -8 or -6AN to carb/rails to 1500hp Electric pump or pumps
-12AN feed/return -8 or to carb/rails 1500 and up.Belt driven pump or multiple electric pumps....
The guide above is only guestimate off the top of my head and more detail would be needed by the fuel system designer to get it right at the cheapest cost....
-
Reply With Quote
