stock psi for mech. fuel pump? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

spinem · 02-21-2010, 08:12 PM

can some one tell me how many psi the stock mechanical fuel pump makes on a non computer controlled 1/2T 350?

cableguy0 · 02-21-2010, 08:20 PM

They vary but it should between between 5-7 psi. some lower some higher.

Restrorob · 02-21-2010, 08:26 PM

spinem · 02-21-2010, 11:10 PM

really? i figured it to be higher? 7only huh?

Restrorob · 02-21-2010, 11:31 PM

Yep 7 lbs, That's the max pressure on the Demon carb sitting on my 502. Much over that will result in running rich/flooding.....

diponyou · 02-21-2010, 11:52 PM

Quote:

Originally Posted by Restrorob

Yep 7 lbs, That's the max pressure on the Demon carb sitting on my 502. Much over that will result in running rich/flooding.....

yea yea we all know you got a sweet 502,you dont have to rub it in...

im just jealous

Restrorob · 02-22-2010, 12:06 AM

Sorry, I only mentioned it to use as reference to even a big block runs low fuel pressures as well.

If ya believe that one I'll tell ya another.....

diponyou · 02-22-2010, 12:24 AM

ahahahaha

spinem · 02-22-2010, 12:26 AM

awesome, thanks guys!

cableguy0 · 02-22-2010, 09:44 AM

The fuel pressure has nothing to do with the engine size. Carburetors cannot handle more than 7psi in most cases because it will push the needles off the seat and flood the carb. The only exception would be spring loaded needles and seats used in off road and race carbs but even they will get pushed open with fuel pressure too high. Edelbrocks are finnicky too they dont like more than 5.5psi or they will run rich at idle.

02-21-2010, 08:12 PM	#1
spinem haha, ford guys... Join Date: Feb 2007 Location: Visalia, CA Posts: 576	stock psi for mech. fuel pump? can some one tell me how many psi the stock mechanical fuel pump makes on a non computer controlled 1/2T 350?

02-21-2010, 08:20 PM	#2
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	Re: stock psi for mech. fuel pump? They vary but it should between between 5-7 psi. some lower some higher. __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

02-21-2010, 08:26 PM	#3
Restrorob The One And Only !!! Join Date: Jan 2007 Location: Hole in the woods Florida Posts: 4,567	Re: stock psi for mech. fuel pump? __________________ 93 Jeep XJ 88 Buick La Sabra Toys; 88 TA-GTA in the works.... 97 GMC Ext. Cab 502 Crate 5 Spd......Sucks Gas But Haulz Azz ! The primary function of an Engineer is to make it difficult for the Fabricator and impossible for the Mechanic. *"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!*

02-21-2010, 11:10 PM	#4
spinem haha, ford guys... Join Date: Feb 2007 Location: Visalia, CA Posts: 576	Re: stock psi for mech. fuel pump? really? i figured it to be higher? 7only huh?

02-21-2010, 11:31 PM	#5
Restrorob The One And Only !!! Join Date: Jan 2007 Location: Hole in the woods Florida Posts: 4,567	Re: stock psi for mech. fuel pump? Yep 7 lbs, That's the max pressure on the Demon carb sitting on my 502. Much over that will result in running rich/flooding..... __________________ 93 Jeep XJ 88 Buick La Sabra Toys; 88 TA-GTA in the works.... 97 GMC Ext. Cab 502 Crate 5 Spd......Sucks Gas But Haulz Azz ! The primary function of an Engineer is to make it difficult for the Fabricator and impossible for the Mechanic. *"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!*

02-22-2010, 12:06 AM	#7
Restrorob The One And Only !!! Join Date: Jan 2007 Location: Hole in the woods Florida Posts: 4,567	Re: stock psi for mech. fuel pump? Sorry, I only mentioned it to use as reference to even a big block runs low fuel pressures as well. If ya believe that one I'll tell ya another..... __________________ 93 Jeep XJ 88 Buick La Sabra Toys; 88 TA-GTA in the works.... 97 GMC Ext. Cab 502 Crate 5 Spd......Sucks Gas But Haulz Azz ! The primary function of an Engineer is to make it difficult for the Fabricator and impossible for the Mechanic. *"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!* Last edited by Restrorob; 02-22-2010 at 12:07 AM.

02-22-2010, 12:24 AM	#8
diponyou Registered User Join Date: Jan 2010 Location: duluth,ga Posts: 201	Re: stock psi for mech. fuel pump? ahahahaha

02-22-2010, 12:26 AM	#9
spinem haha, ford guys... Join Date: Feb 2007 Location: Visalia, CA Posts: 576	Re: stock psi for mech. fuel pump? awesome, thanks guys!

02-22-2010, 09:44 AM	#10
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	Re: stock psi for mech. fuel pump? The fuel pressure has nothing to do with the engine size. Carburetors cannot handle more than 7psi in most cases because it will push the needles off the seat and flood the carb. The only exception would be spring loaded needles and seats used in off road and race carbs but even they will get pushed open with fuel pressure too high. Edelbrocks are finnicky too they dont like more than 5.5psi or they will run rich at idle. __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.



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