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Old 06-27-2022, 02:02 PM
JUDGE3 JUDGE3 is offline
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Default Holley 50cc fwd acl pump

would changing to a 50cc fwd acl pump be beneficial for most performance applications using a dual plane intake?

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Old 06-27-2022, 02:41 PM
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If you have a hesitation while accelerating and believe it is lack of fuel from the carb, then moving the 50 up front is ok. I did that while drag racing, but was fine on the street with the 30 up front and 50 in rear. Now with the smaller cam, I have the 50 in the rear of the carb ( 30 up front ) while racing. I use a dual plane intake.

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Old 06-27-2022, 03:32 PM
74Grandville 74Grandville is offline
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50cc will give you a longer shot. I also believe depending on the size of the nozel will depend on which you would use, 30cc vs 50cc.

Usually Dual plane manifolds do not need as large of a shot compared to a single plain intake. (smaller plenum)

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Old 06-27-2022, 03:36 PM
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Have you experimented with the pump cam any???

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Old 06-27-2022, 04:00 PM
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Please note that with a Holley whenever you have reset the idle speed from where you had everything working perfectly, you then also need to readjust the pump spring and it’s clearance.

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Old 06-27-2022, 05:15 PM
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The "30 cc" pump (per 10 strikes) works fine for most street applications on carbs up to 850 cfm. 3 cc-s for ONE carb stroke.

There is some benefit on a "Street Car", that is run on the track with an aftermarket converter, with the "50 cc" pump. 5 cc-s for ONE carb stroke.

Tom V.

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Old 06-29-2022, 08:41 PM
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My combo loves the 50cc pump up front. RPM or TII manofold. 850 dp annular boosters

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Old 06-30-2022, 08:43 PM
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