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Discussion Starter · #1 ·
So busy dialing in my 383 stroker with 850 double pumper..

When I floor it it pulls REAL hard for 3s then dies- catches again and idles and I can drive it, I have a shop type 4psi pump that works fine, pumps a fair bit but its a 36gph pump.. How does gph equate ito performance?

I will test my holley race pump today and see if it changes- but curious about what gph rate applies to what hp/rpm ..

Current pump (installed rear by tank):

Edelbrock 38gph 12v pump
4-7psi



Testing into a clear bottle it seems it delivers plenty of volume but perhaps not enough to keep float bowls full?
 

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38 gallons per hour is fee flow, that is how pumps are measured. By the time that reduces via the frictional reduction in the fuel lines and the G force dynamics of vehicle maneuvering the
delivery at the carb is much less that the rated free delivery.

For a high powered engine the fuel pump needs to be rated around 90 gallons per hour free flow.

Bogie
 

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Discussion Starter · #4 · (Edited)
thanks - well I put in a holley red today and a fuel psi regulator - I did notice the pump weeping out of the hole for a small time then cleared, but the pump put out 9-10psi instead of 7 causing flooding = requiring psi regulator.. is it possible to rebuild these or at least get the 7psi to work? Tired of plumbing junk and more junk.. anyway-

same thing / stall on accel after 3s.. for now we can at least rule out the fuel pump but im wondering if the needles are too restrictive or maybe the float drop isnt sufficient - the ones that came in the kit both leaked, ill give em another shot 2moro-

The carb was a new reman from Holley and in mint shape apart from the carb gooping gas thru the vent etc.. I grabbed 2 new needles I had and they held up-

Car hauls then falls on its face soon as I imagine the float bowls empty.. i can basically just cruise and thats it-

at slow speeds it builds enough fuel for me to mash it but cruising 40-60 no chance-
 

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Does your Holley carb have a "Vent Baffle/Whistle" installed on the primary metering block (see image below - yellow arrow)?
Toy Rectangle Electric blue Font Auto part

If not... when you aggressively accelerate from a standing stop, fuel will be pushed back within the fuel bowls towards the back of the carb. This could cause gas to spill out of the primary vent tube and into the primary throttle bores of your carb... causing a temporary flooding condition (causing the engine to momentarily bog/stall).

A quick test/fix is to take a piece of rubber tubing and connect the front (primary) carb vent with the rear (secondary) carb vent AND also cut a small "breather hole" at the top of this rubber tube so the carb can properly vent the fuel bowls (see image below).
Motor vehicle Automotive tire Gas Auto part Electrical wiring

P.S... Make sure the floats are adjusted correctly.
 

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Discussion Starter · #6 ·
tx - i can try that, i did order new needle and seat assemblies form holley- fuel levels level with bottom of sight glass on both sides.. but i didnt verify float drop (if the brawlers have this as a setting)

might pull bowls later - but the mondo fuel pump didnt make a diff at all-

Man by the time ive warmed the vic jr 1 gallon of gas already gone lol - this thing DRINKS gas!
 

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Sight glass style bowls...the fuel level should be middle of window, not bottom edge.

You may just have it set too low and combined with available distance for float drop ends up not being enough range of motion.
 

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tx - i can try that, i did order new needle and seat assemblies form holley- fuel levels level with bottom of sight glass on both sides.. but i didnt verify float drop (if the brawlers have this as a setting)

might pull bowls later - but the mondo fuel pump didnt make a diff at all-

Man by the time ive warmed the vic jr 1 gallon of gas already gone lol - this thing DRINKS gas!

Fuel bowl levels are way too low. You should be from the middle of the sight glass to the 2/3rds mark. I run mine a bit high to overcome the bowls going empty. You also need to make sure of the needle and seat size you are putting in the bowls. You can't just put anything in there. Most of them are .110 but you probably need at least .130 if not the .150 size. Pressure at the bowls should be around 7-7.5 and I don't think you ever mentioned what size lines you were running from the pump to the regulator and the regulator to the bowls.
 

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Discussion Starter · #9 ·
Hi thanks - 3/8 from the rear, Holley Red with psi reg but its maxed at 5.5 - I had no idea about the fuel level so thats first on the list with the needle swap.. do the brawlers have a float drop spec? Just been too busy at the shop since thanksgiving but posi arrived today so will def be getting in there soon b4 the rain starts- gotta pull rear, weld axle tubes, setup posi, was hoping to get a rear disc conversion on but not sure i wanna lose the parking brake..

Iirc carb came with 120 needles that both leaked, i could NOT get them to not leak- popped in some 95s or something I had laying around and they held up ok (same pump back then)..

I received to 130s yesterday new form Holley so will pop those in and also see how it goes- need to see why my brand new AEM wideband is DOA...



Fuel bowl levels are way too low. You should be from the middle of the sight glass to the 2/3rds mark. I run mine a bit high to overcome the bowls going empty. You also need to make sure of the needle and seat size you are putting in the bowls. You can't just put anything in there. Most of them are .110 but you probably need at least .130 if not the .150 size. Pressure at the bowls should be around 7-7.5 and I don't think you ever mentioned what size lines you were running from the pump to the regulator and the regulator to the bowls.
 

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If you flip the bowl over and use a 3/8" drill bit between the top of the float and the roof of the bowl - that is the ball park. Final adjustment is made with it idling. You say the regulator has no adjustment beyond 5.5? I would be looking for one of them that adjust from 4.5 to about 9. And 3/8 from the rear is minimal but what about between the regulator and the bowls?
 

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Discussion Starter · #11 ·
Good point - I have one as described being delivered 2moro.. this was just an emergency trying to see if the pump was an issue..

3/8 all the way to the front by carbs - and then 3/8 AN to the bowls.. gotcha on the float drop ill bear all this in mind when i get the tools out in a day or 2 and report back. I need to time - dont think im getting past 28, recommended to disconnect the vac, run about 18-20 initial and 14-16 in the HEI all in about 3 grand? Sound about right more or less for a baseline?

If you flip the bowl over and use a 3/8" drill bit between the top of the float and the roof of the bowl - that is the ball park. Final adjustment is made with it idling. You say the regulator has no adjustment beyond 5.5? I would be looking for one of them that adjust from 4.5 to about 9. And 3/8 from the rear is minimal but what about between the regulator and the bowls?
 

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We have a lot of discussions here about timing curves. What you have is a start and once you the carb stuff resolved you can start chasing the timing. Engine power and torque, vehicle weight, how it's driven, rear gear - all of it can have an impact. And with today's lousy fuel,, to get the best out of it you really have to fine tune. Back when we had good fuel, you could miss it by a mile and it still would run okay.
 

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Discussion Starter · #15 ·
Just on a sidenote this thing is THIRSTY - DAM!!!!! maybe from all the pedal tapping to keep her alive and tuning but darn the fuel is POURING :/ I almost dont even wanna know :censored: sheesh from 23mpg highway on the thrifty (3)50 this is a wild difference yikes - but of course that was the intention on the build :)
 

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Discussion Starter · #16 ·
ok got float levels mid level when running on both sides. havent pulled carb just yet (aem wideband is now registering but idle is off scale - past 17 or whatever).. when i accel to around 2500 it quickly goes down to around 13.5.

turning idle screws in doesnt seem to bring it down (yes i do wait a few s and blip it a bit)..

currently only reading pass side tail pipe - not sure if the vic jr is feeding all the cyls? I can compare to driver side pipe-
 

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Assuming the wideband isn't FUBAR...
Turning idle mix screw IN just leans it out more.....if it is reading off scale lean 17 then you need to open them up OUT.

13.5 AFR at 2500 rpm(if that is cruising rpm) is a hair fat/rich, but not terrible.
If that is 13.5 WHILE accelerating....then it is still quite lean.

Vic Jr is a single plane, so all four barrels can and do feed each/every cylinder.
 

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Discussion Starter · #18 ·
sensor working - it was cos it was too close to the tailpipe, at idle too much fresh air.. at half throttle it was around 15- I tuned it by the exhaust smell, theres a certain sweet smell when tuned right :)

Either way nice to have the gauge as reference-

Will take it down the road later today and report back on the stalling issue..
 
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