quick carburetor question

69mach351 · 09-11-2002, 05:57 PM

Hello again, my 4 barrel Holley carburetor is leaking gas out of a hole in the bottom ( not in the barrel, just outside the barrel on the side of the two primaries.) Is this normal? At the end of the day the gas in the primarie float bowl gets very low. Also, if I buy a new 4v carburetor, what is the best size if I have a 351W? I intend to make it an everyday driver, and don't intend to do much heavy road-racing. Thanks so much for any help. I am stuck right now so I would be grateful for any imput....David Bridwell

p.s. I don't know what size carb I have now, I took it to parts stores, and looked in a Holley book but the number is not listed.
(80508 3176) (R-6931)

gofastmercury · 09-11-2002, 10:34 PM

First, whats the list number?
Second, no, fuel leaking out is not normal. I'm sure a rebuild kit will fix it. If you dont want to fix it or you think its just not worth your while, a good old carter AFB (edelbrock) would be a nice street carb, usally works right out of the box, about a 650cfm would work well. If you love your holleys, a 750 vac secondary, with metering blocks front and back would work too, you tend to have to play with holleys to make them work, but if you have the time to fiddle with em, they work great.

Rev · 09-12-2002, 06:58 PM

The Road Demon is another good choice. I use the 625 CFM on my 306 and it's about right. It should work for you well also on a mild 351. The only problem I had was the electric choke looks and acts like it was made in Taiwan. The carb itself is great. The Holley Avenger would be another good choice. I might pick this one if I was doing it over again.

Both of these are supposed to work well right out of the box with no tuning needed and I think that's true. Cost for these carbs is $325-350 from Summit.

Rev

69mach351 · 09-14-2002, 03:35 PM

Thanks so much for the help. I am going to buy another carburetor, the 650 sounds good. I think I will stick with the Holley. It depends on the price. Some parts did not match up to my carb when I rebuilt it recently so I have to spend the bucks and buy a new one. As long as the car gets back on the road!!
Thanks, David

hobgoblin351 · 09-14-2002, 05:17 PM

Hey the 650 is the right size. Unless you've done heavy mods to the 351 it wont flow much more than that anyway. And , if it did it would only be at WOT. Also go with the vac seconds, unless it is a large cam, the lopey idle and low vac at lide would throw it off some.

mustangman65_79 · 09-14-2002, 06:48 PM

I got a 750 cfm holley vac 4bbl zinc finnish for only $250. Only $9 more then a 600, and $50 or more less then a 650. I go that route.

1968FastbackN20 · 09-14-2002, 06:55 PM

I run a 750 vacuum secondary on a mild 351W with no problems. I recomand you get the vac. secondaries.

09-11-2002, 05:57 PM	#1
69mach351 Registered Member Join Date: Jan 2002 Location: California- Hollister Posts: 14	quick carburetor question Hello again, my 4 barrel Holley carburetor is leaking gas out of a hole in the bottom ( not in the barrel, just outside the barrel on the side of the two primaries.) Is this normal? At the end of the day the gas in the primarie float bowl gets very low. Also, if I buy a new 4v carburetor, what is the best size if I have a 351W? I intend to make it an everyday driver, and don't intend to do much heavy road-racing. Thanks so much for any help. I am stuck right now so I would be grateful for any imput....David Bridwell p.s. I don't know what size carb I have now, I took it to parts stores, and looked in a Holley book but the number is not listed. (80508 3176) (R-6931)

09-11-2002, 10:34 PM	#2
gofastmercury Registered Member Join Date: May 2001 Location: calgary alberta canada Posts: 366	First, whats the list number? Second, no, fuel leaking out is not normal. I'm sure a rebuild kit will fix it. If you dont want to fix it or you think its just not worth your while, a good old carter AFB (edelbrock) would be a nice street carb, usally works right out of the box, about a 650cfm would work well. If you love your holleys, a 750 vac secondary, with metering blocks front and back would work too, you tend to have to play with holleys to make them work, but if you have the time to fiddle with em, they work great. __________________ 93LXcopcarSOLD14.3@96 @ 4500ft 2.02 60ft on street tires. my 67 ranchero NOT A 390 ANY MORE! 460! 3.70's cast manifolds, comp cams 262H, performer, 750DP 100K out of 79 F250 NEW(oct20/02)14.58@95mph 2.3 60 ft corrects to:13.86@100 66 merc comet351w, isky roller 600 lift 268/260@.050, vic jr. 700DP, 5000stall, 4.56's c-4, 3400lbs with driver 12.3@110 @ 4000ft 1.69 60 ft corrects to:11.69@115

09-12-2002, 06:58 PM	#3
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	Road Demon The Road Demon is another good choice. I use the 625 CFM on my 306 and it's about right. It should work for you well also on a mild 351. The only problem I had was the electric choke looks and acts like it was made in Taiwan. The carb itself is great. The Holley Avenger would be another good choice. I might pick this one if I was doing it over again. Both of these are supposed to work well right out of the box with no tuning needed and I think that's true. Cost for these carbs is $325-350 from Summit. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

09-14-2002, 06:48 PM	#6
mustangman65_79 My poor 79 RIP Join Date: Oct 2001 Location: Suisun City, Posts: 2,320	I got a 750 cfm holley vac 4bbl zinc finnish for only $250. Only $9 more then a 600, and $50 or more less then a 650. I go that route. __________________ '84 mustang GT turbo '85 LTD '89 Camaro Irocz z28 '94 Lightning '96 Trans am

09-14-2002, 06:55 PM	#7
1968FastbackN20 Registered Member Join Date: Sep 2002 Location: Tacoma, WA Posts: 13	I run a 750 vacuum secondary on a mild 351W with no problems. I recomand you get the vac. secondaries. __________________ Arron 1968 Fastback Doug's Racing Stables Inc

09-14-2002, 03:35 PM	#4
69mach351 Registered Member Join Date: Jan 2002 Location: California- Hollister Posts: 14	Thanks so much for the help. I am going to buy another carburetor, the 650 sounds good. I think I will stick with the Holley. It depends on the price. Some parts did not match up to my carb when I rebuilt it recently so I have to spend the bucks and buy a new one. As long as the car gets back on the road!! Thanks, David

09-14-2002, 05:17 PM	#5
hobgoblin351 Registered Member Join Date: Sep 2002 Location: NYC Posts: 245	Hey the 650 is the right size. Unless you've done heavy mods to the 351 it wont flow much more than that anyway. And , if it did it would only be at WOT. Also go with the vac seconds, unless it is a large cam, the lopey idle and low vac at lide would throw it off some.

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