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Discussion Starter #1
I am having some issues here with a set of dominators. I have a "street" car that needs some fine tuning and I am all out of ideas.
Here is my combo:

57 chevy all steel 3700lbs
454 big chevy 8.5-1 compression Solid roller
10-71 Mooneyham teflon blower 10lbs boost
Dual 1050cfm Dominators 0-8896-1 Powervalves pluged, 94 jets in fronts 98's out back
A-2000 fuel pump with return style regulator
1/2 aluminum fuel line front to back
PowerGlide with Gear Vendors over drive
32' et streets 4.88 gears

6000 feet above sea level

After reading that here is my problem, I took the car to the track last weekend and found my self to be a bit rich on the bottom and to be extreemly lean on the top end. Even my mph was slow at 118 previously was at 124 before 10-71 upgrade. I have done about all I can do to tune the carbs, Im even using what some say are huge jets and I cant fix the problem and I feel it is time to send them out for machining. So if you have any ideas on tuning or who is more experianced with blower carbs please let me know thanx..
 

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Discussion Starter #6
Ya I think the air bleeds are changeable and there are no kinks in the line and the only way I know that I am lean is by the way too clean plugs after a WOT pass and a little bit of puffing in the lower-cruising rpm's
 

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What kind of a fuel tank do you have? Where is it mounted? Is the fuel line feeding from the rear of the tank or front? Where is your fuel pump located?
Did you flow check fuel delivery at the carbs (1 minute flow into can)?

If your running that big of a jet and it's lean, I would guess you have a fuel delivery problem someplace.

Blessings.........Ron.
 

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Discussion Starter #9
I have heard that it may be a fuel delivery problem also. The tank is in the trunk its a 10 gallon fuel cell with the feed in the rear and the pump is mounted about 2 inches lower than the sump. I will check my flow tomorrow what should I be flowing after 1 minute? The float bowls are all good, Im running 9 psi on the street and I bump it to 11psi at the track just dont know why its not suckin enough through the big jets or if im not flowing enough fuel. The fuel filter is a BG in line filter I dont really care for the BG filter but it was what I had at the time
 

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You might try reducing the regulator pressure to 7-8 PSI. About 20+ years ago I was involved in some Holley needle/seat pressure testing. At that time when you went much above the 7 psi recommended it created so much turbulence in the seat area the flow was actually reduced.

I don't know how that will line up with todays needle/seat, but it might be worth a try.

Also look at the inside of all your fittings. All manufacturers are not the same in inside diameter.

Blessings.........Ron.
 

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I use a B&G 5000 filter before my Magnaflow 500 pump and a #10 after the pump and I get a gallon in 7 seconds up front(free flow).The B&G filter is alot better then there fuel pumps..........That alot of carbs you have for running the blower slow.....Good luck....Oldhead
 

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Discussion Starter #12
ok I took the lines off the carbs and put all four after the regulator, exactly like how it would feed the carbs, inside a 5 gallon bucket and I almost filled it up after 1 minute so aprox. 4.5 gallons per minute. Is that enough flow?
 

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How new is the BG filter ?
Have you tried flowing the system without the filter in place ?

Curious as to why the return line is the same dia as the supply ? Usually the return is smaller.
Looks from your description that you drive this car on the street so safe to assume you run an alternator. Is it putting out full volts at speed ? Fuel pump wiring(proper gauge wire)/relay/ground wires all up to snuff ?

Are the carbs and regulator "boost referenced" ?
As a last resort, you may want to contact Blower Drive Service as they build blower carbs. They may be able to help.
www.blowerdriveservice.com
 

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Discussion Starter #15
No, I have thought of flowing the system without the filter because I had a filter-pressure issue on my procharged car and the filter was the culpret. What I think Im going to do instead of replacing the bg filter is change it to an aeromotive filter since its more available at the speed store and change the feed to 10 AN. Currently the return is the same size-1/2 hard line. The charging system works great as rpms increace so do the volts and when the volts increace the pump pumps harder and the pump is wired with a relay pulling current directly from a distribution block connected to the battery. The carbs are out of the box dominators only jets and accelerator pump nozles have been changed. The regulator is boost referance but if I referance it then with 10 lbs of boost my fuel pressure will jump to like 18psi. I am almost certain i am gonna have to have them put on a flow bench but I wanted more opinions first and to see who will do the best job for roots blowers
 

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Eddie Haskell
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ok I took the lines off the carbs and put all four after the regulator, exactly like how it would feed the carbs, inside a 5 gallon bucket and I almost filled it up after 1 minute so aprox. 4.5 gallons per minute. Is that enough flow?

4.5 gmp=
270gph=
1620 pounds per hr X .50 bsfc=
3240 hp delivery capability

Off the top of my head I'd say you were good, volume goes down with pressure. You might do the same measurement with the return into a bucket. If it has a return type regulator.
 

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Discussion Starter #17
Ok well I have been doing some research, what I found is that I am over Carb'd for what I am running according to the calculations 454 with 10lbs shold have around 1600 cfms. So if I have too much CFM's would that mean that the carbs are not receiving the proper vaccum signal?
 

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Call Dean Nickerson @ Nickerson performace 215-781-1370
he did a set of carb for a supercharged boat i had and they worked very well
 

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Ok well I have been doing some research, what I found is that I am over Carb'd for what I am running according to the calculations 454 with 10lbs shold have around 1600 cfms. So if I have too much CFM's would that mean that the carbs are not receiving the proper vaccum signal?
no!only that you are limited to the potential of that cfm.the BDS site states that a 30% oversize is ok but may start to cause distrebution problems of some type.i was running 850's and went to 1250's and the engine seems a lot happier temp and performance wise.
 

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TRY ONE DOMINATOR,Doesn't cost anything to try!!! Good luck....Oldhead
 
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