Not sure if this is good or bad: Holley 2bbl carb

Got to looking at the Holley 2bbl carb that I got for I6.

Was supposed to be a 350cfm 2-v. Ran numbers and its a 500cfm-2v with 50cc accelerator pump and 73 sized jets.

I think engine will probably be OK with 500cfm 2bbl. No so sure about the 50cc accelerator pump and I think the 73 main jets are too big.

The float bowel has a brass center pivot float. We swapped on my other Holley float bowel which is non center pivot but has a solid black float.

This is in a 85 Mustang Coupe currently with C4 auto and is getting a T3 turbo.

Head is D8 log head with 1.80"int and 1.50" exh, 270deg cam, getting it ported and polished probably in week or two. Top of head milled for Holley 2300 adapter plate.

What should I jet this at?

The good news is there are no holes for choke linkage and stuff, just have to cut down air horn.

Thanks for any advice

Mark

8) since you are turboing this motor, i would leave the jetting where it is until you have the motor together and running. you may find that a 73 jet is just what you need, but you wont know until you have time on the motor. as to the accelerator pump, the 50cc pump might be a bit much, and if you find that is the case you can swap it for the smaller 38cc pump as they are a direct swap.

Mark, i would start with the 73 jet, but definately keep the 50cc pump. Seems like these small engine require a lot of pump shot to cover up lean holes in the fuel curve.

wsa111":39vvb4l9 said:

Mark, i would start with the 73 jet, but definately keep the 50cc pump. Seems like these small engine require a lot of pump shot to cover up lean holes in the fuel curve.

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8) that sometimes is the case, and i agree that he should start with the carb as is for a baseline and work from there.

HOwdy Mark:

There is a list # stamped on the outside of the choke air horn (assuming the air horn is still there). #7448 = 350. #4412 = 500. Once running, in addition to main jets you will need to refine the idle and transition circuits, as well as the power valve size and power valve channel restrictions. Bill is the man to go to for help with it all.

Adios, David

I dont have carb in front of me atm but yeah the p/n was on the air horn. It was 4412-and a number. I ran the 4412 and came up with the 500cfm.

I know jets because I swapped float bowels and while off I looked to see what size jets. The original float bowel is a center pivot with brass float. The other bowel I swapped on was a side pivot but has a black foam solid float.

I swapped bowels because I am having problems finding the plugs and fuel line fitting for the center pivot float bowel. The other bowel has one fine thread fitting. If I can find fittings and a solid float for center pivot I will swap that back on.

I knew I had a 50cc accelerator pump as soon as I saw it.