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I have a holley 110 GPH fuel pump that Flows 110 gph free flow at 6.5-8 psi maximum. I have a regulator on it and I have adjusted to the max but still only get about 5lbs of pressure. My problem is in second gear the car coughs and sputters and 5600 rpm and I have to shift. I jetted the carb up to 68p and 76s still the same. Should I put a pressure gauge on the cowl to watch it in 2nd or just bypass the regulator?? I thought that I heard holley carbs can't handle over 7lbs on pressure?
 

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Most o the Holley pumps require a regulator and a lot of the Holley regulators suck. I would remove the reg and verifiy system pressure. I set mine at 6.5 PSI. This is why I run Mallory pumps - the Mallory 110 in the Mustang is internally regulated at 7 and it's an install and run deal. We've had no issues with it, running a 400 HP 351C, shifting at 6000+ twice per pass. 3/8" stock line and stock pickup, large Fram filter.

I started with a system using a Holley 110 and a regulator and had similar problems. I did two things - 1) replaced the tank pickup with a 3/8 line and 2) sold all the Holley fuel stuff at a swap meet.

The Falcon runs a 140 GPH return system, it's good to near 600HP.
 

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Discussion Starter #3
Thanks I think I will remove the regulator tonight and check the pressure and maybe adjust the floats if needed. By the way I bought a Boss Hog street bandit 3200 to 3600 for my car and it works awesome! He just came out with it for the old 24 spline trans which is not listed on his site and that's what I had. The price was right and I can't wait to see if my 60' times are in the 1.?? insted of 2.13 average.
 

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Just a thought, isn't it amazing that an engine can suck ~100gph through four tiny-ass orifices in the carb? What kinda velocity would the fuel have to wedge through the jet that quickly? Friggin amazing lol.

_________________
'86 Bronco, 300hp 460, E4OD
'85 Ranger, 350hp 289, T5, [email protected] (1.96 60') on street tires


<font size=-1>[ This Message was edited by: Motorhead on 5/3/07 5:51am ]</font>
 

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I have a couple of questions for you. Are you using a liquid filled gauge to measure your fuel pressure? Where is the gauge located? What size filter are you using? Have you replaced the fuel line and what size line do you have? Here is why I'm asking these questions. Liquid filled gauges in the engine compartment can screw you up. The internal pressure of the liquid filled gauge can change drasticle with temperature change. This would result in a false pressure reading. If the filter micron rating is on the small size (10 micron) you could cause the pump to cavitate when demand increases. It is recommended to use a 100 micron filter between the tank and pump. A 10 micro filter should be placed beteen the pump and the carb. If the fuel line has been changed there may be a small air leak that can cause the pump to cavitate. Do you have a way to measure your air fuel ratio during a run? Good luck.
Robert
 

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Discussion Starter #9
I am using a holley gauge that is on the duel feed line. I have a JEG'S Compact Billet In-Line Fuel Filters with a a removable 40 micron stainless element. I have the stock metal fuel line. Yeah I have a ;iquid filled autometer gauge that I am going to put on the cowl. Dont really have a good way to measure air fuel. What would I need? I have a holley 650 DP on the car. I took the refulator off tonight and I am going to test the car tomorrow. One thing that I did notice is that now that I increased the jets it seems to sputter in 1st to 2nd after 5600 instead of doing it in 2nd to 3rd. I will try it and let you guys know, thanks for the input.
 

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On 2007-05-02 14:51, Motorhead wrote:
Just a thought, isn't it amazing that an engine can suck ~100gph through four tiny-ass orifices in the carb? What kinda velocity would the fuel have to wedge through the jet that quickly? Friggin amazing lol.
I watched my 351C do it repeatedly with 5 PSI showing on the gauge at the carb. That was the old dead head system. Sucker shut down at 5300 like it had a rev limiter. Experienced racer says "out of fuel". I say "Bah, got pressure". "Out of fuel" "Bah" "Out of fuel" "Bah" - changed pumps and fuel setup, discoverd stock pickup necked down to less than 5/16"...hmmm must have been out of fuel.
 

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Discussion Starter #11
Yeah I think that you are right I just cant believe my cars needs that much fuel I only in the 14's. With a mild setup but I guess I will keep working with it and see what happens. Thanks CKelly
 

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I used to run stock lines and a Holley 110gph mech pump.I installed a gage at the cowl and watched the pressure go away at 5000.
I did what you guys told me:changed fuel lines to 3/8" from pickup to carb,put in larger jets and the pressure only drops to 4.8-5psi.
The car runs awsome,what a difference.
By the way the old crappy filter gave up,changed to a better one and gained a little pressure there too.
Have a nice day/Gresse
I run no regulator.
_________________
My combo:289"030 dished piston ported-66 heads with 1.94-1.60valves.
Comp292H 244-244-534-534 110 lobesep.
Portmatched Vic jr Holley 650dp with 70F-79R jets and 3.5pv.Holley mech 110gph pump.3/8"line.
1 1/2" longtube headers through full 3" exhaust.
Timing int16* total36* in at 2000rpm Mallory mbi dist and Mallory coil.
Plugs are Motorcraft BSF42C gap set .040"
C4 trans 10"TCI superstreet fighter.
8" 4.11 rear with tractionlok

<font size=-1>[ This Message was edited by: gresse on 5/4/07 4:04pm ]</font>

<font size=-1>[ This Message was edited by: gresse on 5/4/07 4:17pm ]</font>
 

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A hard and fast 1/4 mile run will easily use 1/4 to 1/2 a gallon of gas.

So 1/2 gallon + pumping action in 13 seconds is what is needed to keep your bowls filled.
 

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I pulled my old gas tank in the 63 and drilled out the old pick-up tube & replaced with 3/8 line. Your 65 is probably same as the 63, just a sippin' straw.
 

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On 2007-05-02 14:51, Motorhead wrote:
Just a thought, isn't it amazing that an engine can suck ~100gph through four tiny-ass orifices in the carb? What kinda velocity would the fuel have to wedge through the jet that quickly? Friggin amazing lol.
<font size=-1>[ This Message was edited by: Motorhead on 5/3/07 5:51am ]</font>
I am sure Motorhead was being sarcastic. You don't need that kind of fuel delivery. A holley red electric pump will do the job for you (the version that has a regulator built in) and then some. Raise you float levels a bit more and see if that helps your cut out problem.
 

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On 2007-05-04 03:50, Mikes66 wrote:
A hard and fast 1/4 mile run will easily use 1/4 to 1/2 a gallon of gas.

So 1/2 gallon + pumping action in 13 seconds is what is needed to keep your bowls filled.
Good response. I ran through more than 4 gallons last weekend with 11 full throttle 1/4 mile runs and 4 or so jet changes last weekend.
 

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Discussion Starter #18
Well I took the regulator off tonight and tried it. The pressure seems to stay 6.5 at idle (better than before) and floats are right on, still don't have a unit on the cowl. I am going to try 70p 78s in the carb and see what happens. My total timing is 38 degrees is that too much. I also double checked my rev limiter and it was set correctly.
 

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Discussion Starter #19
Tried 70p and 78 secondard and it seemed a little better in 2nd to 3rd but is still sputtering at 5600. I am going to race it tomorrow and just see if my 60ft times improve and overall MPH with the jet change and torque converter. I am ordering a fuel pressure regulator line from jegs tonight so i can see what the heck is going on for sure.
 

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Discussion Starter #20
Well I installed my fuel pressure gauge and the fuel pressure never drops below 6lbs through the quarter mile. I have narrowed it down to weak valve springs. I am going to be putting in a bigger cam and new valve springs in july since there is no racing that month and see how that works. Thanks for all of the help!
 
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