carb selection question

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Jul 4, 2004 | 10:30 PM

tcd

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carb selection question

I've a 351 windsor that has a 4bbl Holley 4180 on top I would like to convert the

into a 2bbl holley carb what type might I use? Thanks! TCD

Jul 4, 2004 | 11:06 PM

Putt

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From: Colville, Washington

You will need to explain what you want to accomplish by that swap first.
Holley List number 4412 is a 500 cfm 2 barrel.

I must ask WHY?

Jul 4, 2004 | 11:56 PM

tcd

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I have a 1986 Ford 350(engine: 351 windsor ,5.8 L ,V-8; transmission: Borg Waner 4 speed T-19-2WD) that I just bought and it has a " holley /manufactured for motorcraft carb /" on top ,and the numbers on it are E6HE-9510-GB andLIST-50428.

I want to do this in an effort to save on feul consumption. I don't believe I really need the 4 bbl action ,especially when I don't ever plan to get the engine up to anything more than 4000 rpms. According to the cfm formula ( engine size x max RPM / 3546 = cmf needed), for my situation, I only need a 400 or 450 cfm. Tell me what ya think . Thanks TCD

Last edited by tcd; Jul 5, 2004 at 12:36 AM.

Jul 5, 2004 | 02:52 PM

Putt

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From: Colville, Washington

The 4 brl won't cost you any fuel mileage if the secondaries never open. The primary side of the 4 brl is prolly 1 1/4" in dia., the 4412 Holley is 1 3/8" in dia. The 4412 uses larger jets than the 4 brl, since it has to feed all ranges of engine load and speed. For example a 4180 shown in my Holley book uses size 61 jets, the 4412 uses size 73 jets.

I would suggest tuning the 4 brl for mileage, rather than installing an adapter and 2 brl.

Jul 6, 2004 | 01:43 AM

mako5972

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From: Ocala, Florida

You get better fuel economy with the 4 barrel carburetor. I had a 2 barrel on my 351W. I changed to a 4 barrel and increased my fuel economy. The reason is that the primaries on the 4 barrel are smaller than the primary on the 2 barrel. Just keep your foot out of the accelerater.

Jul 6, 2004 | 01:47 AM

mako5972

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From: Ocala, Florida

Let my clarify something. With all things being equal it would have to be carburetors of the same size. Instead of getting a 500cfm 2 barrel carburetor, get a 500 cfm 4 barrel carburetor and you will get better fuel economy.

Jul 6, 2004 | 06:04 PM

tcd

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Well guys I'll tell you what , this is what I have done since I wrote my last post here and before I've read any of you guy's replies....... I got an adapter plate and installed a 2 bbl motorcraft 2150A ( very similar to a Holley 2100) that I rebuilt my self. Anyway these are the results .......I drove 32 miles and used almost 2 gallons of gas as compared to the 4180's 8.9miles a gallons. It accelerates fairly well (the engine) ..and there's power, how ever these are just preliminary results, although promising ,since I still need to do some adjustments and recheck the timing and vaccum readings but all and all the only thing is when I accelerate there's a noticeable hissing sound ...... I wonder what that might be ....... tell me what you think. Thanks for respponding....TCD