Hlolley Carb Jets

[oilslick]

Just bought a used Holley 7448, 350 cfm 2bl carb. It's dumping massive amounts of fuel into the engine and we've made all the possible adjustments. Any quick way to check the jets that are in the carb and what are the best jets for a 4 banger for 2.3L for a 3/8 mile track? Thanks.

[Racedad]

RIch condition some common problems on a Holley:
Blown/leaking power valve.
Shrunken gaskets.
Leaking or mis-adjusted needle valves.
Bad needle valve oring.
Pullover.
I think we run 56-58 jets on a 7448 with power valve eliminator.

[84Dave]

Is 'dumped' fuel exiting from the accelerator 'squirters' or boosters when you look down the carb with the engine running? Have checked or changed the power-valve with a new one? With the engine running & the sight-plug removed from the bowl, what's your fuel level? What fuel pressure are you running? Change the rubber o-ring on the needle/seat assembly? If the float is brass, remove and shake the float for internal fuel/leak? When you look at the bottom side of the throttle blades, how much of the two transfer slots are exposed below the throttle blades? -Dave-

[7uptruckracer]

On our Fords I ran we ran stock EFI intake, Solid Cam/Lifters. Stock Valves all that stuff and turned about 7500 on a 4/10 mile track. We ran 39* of timing, I built my carbs to run a 25 anti pullover squirter, i prefer the dog leg boosters. 4.5 Power Valve, 72 Jet on 110 fuel, .110 Needle and seat with a 30cc pump, on a white or orange pump cam in the #1 position. Check your accelerator pump arm clearance, your float level, I ran the stock weight underneath the squirter, Check your gaskets your, Idle Mixture screws, and use the bowl spill over baffles and make sure you have a power valve anti-blow by kit installed in the base plate as well.

[little302]

If uv made every possible adjustment... You already know what the jets are.. If not, then you havent checked the one of the most important items in your search. Take it off and take it apart.. There are no short cuts.. You will only cause more frustration and problems. Youshould look it over and replace any and all gaskets and do general maintenance.. If you just got it from a guy that ran a 4cyl and bolted it on.... Theres your mistake... Did he have the same, head, cam , intake, cc, ignition, fuel, etc that you are running? What if it was an alcohol carb? Then it has huge jets compared to a fuel carb.. What are your engine rules? Cam, head etc.... all this matters...Do ur homework, and listen to the previous posts.. These men are right on target.. When you are done and it works properly, get a vacuum guage out and use it on the carb.. It WILL make a huge difference in throttle response, and loading up at idle..If you dont know how... call me.. This is just another simple tuning device that is largely overlooked. Any questions call 573 208 3528.. after 6pm. Not after 1 am.. Jason

[csj1]

Check the Power Value gasket to make sure it is seate3d properly and not damaged. If it is ok I would replace the power valve by default with the correct size for a 350cfm carb or block it off all together. We block them off.

[Old Rob]

Holley jet number does not always reflect the accurate flow of given jet. In the technical section of www.powerbyace.com there is a chart that shows the holley jet number, orfice diameter and the orfice area. The area is the most accurate way of determining flow differences, short of useing a flow fixture.