Chris'69Mach 23 Report post Posted June 20, 2013 Does anyone know if http://www.jegs.com/i/Holley/510/0-80770K/10002/-1?parentProductId= would work on my 1970 351 Cleveland .... I just am not a carb guy. I believe I have a 500 or 600 something single pump Holley currently that is wore out and a rebuild kit more than likely won't fix where it is leaking gas. Thanks in advance for the input. Quote Share this post Link to post Share on other sites
Chris'69Mach 23 Report post Posted June 20, 2013 Does anyone know if http://www.jegs.com/i/Holley/510/0-80770K/10002/-1?parentProductId= would work on my 1970 351 Cleveland .... I just am not a carb guy. I believe I have a 500 or 600 something single pump Holley currently that is wore out and a rebuild kit more than likely won't fix where it is leaking gas. Thanks in advance for the input. Quote Share this post Link to post Share on other sites
FrozenMonkey 12 Report post Posted June 20, 2013 Assuming you have a 4v intake, yes it will work, although a 770 is pretty big for a stock setup. You'd need a pretty radical engine to really need to have that size of carb. 600-650 cfm will yield better results, IMO. Quote Share this post Link to post Share on other sites
FrozenMonkey 12 Report post Posted June 20, 2013 Assuming you have a 4v intake, yes it will work, although a 770 is pretty big for a stock setup. You'd need a pretty radical engine to really need to have that size of carb. 600-650 cfm will yield better results, IMO. Quote Share this post Link to post Share on other sites
Chris'69Mach 23 Report post Posted June 21, 2013 So ... this one then? http://www.jegs.com/i/Holley/510/0-80670K/10002/-1?parentProductId= Quote Share this post Link to post Share on other sites
Chris'69Mach 23 Report post Posted June 21, 2013 So ... this one then? http://www.jegs.com/i/Holley/510/0-80670K/10002/-1?parentProductId= Quote Share this post Link to post Share on other sites
Print Dad 58 Report post Posted June 21, 2013 Hello Suullio, One of the biggest mistakes people make when selecting a carb is thinking bigger is better. On a stock motor I think you would have much better results with this. http://www.jegs.com/i/Holley/510/0-80570K/10002/-1?parentProductId=749689 I know it may sound small - -BUT the car will perform very well with this carb in my opinion. Print Dad Quote Share this post Link to post Share on other sites
Print Dad 58 Report post Posted June 21, 2013 Hello Suullio, One of the biggest mistakes people make when selecting a carb is thinking bigger is better. On a stock motor I think you would have much better results with this. http://www.jegs.com/i/Holley/510/0-80570K/10002/-1?parentProductId=749689 I know it may sound small - -BUT the car will perform very well with this carb in my opinion. Print Dad Quote Share this post Link to post Share on other sites
LoneWolf2U 136 Report post Posted June 21, 2013 Look at Summits carb in the 600 series. Its a cross between Holley and motorcraft designs. Its a plug and play for the 351ci engine. I put one on a 302 and only needed to change the jets, downsized to 66's to make it run perfect. Quote Share this post Link to post Share on other sites
LoneWolf2U 136 Report post Posted June 21, 2013 Look at Summits carb in the 600 series. Its a cross between Holley and motorcraft designs. Its a plug and play for the 351ci engine. I put one on a 302 and only needed to change the jets, downsized to 66's to make it run perfect. Quote Share this post Link to post Share on other sites
RogerC 136 Report post Posted June 21, 2013 (edited) From the DeTomaso Internet Community, an article in a sticky by George Pence http://pantera.infopop.cc/eve/forums/a/tpc/f/5650045562/m/319104265 Four Barrel Carburetors At 6000 rpm a 351 cubic inch motor would theoretically inhale 609 cubic feet of air per minute if the volumetric efficiency were 100%. At 7000 rpm the same motor would inhale 710 cubic feet of air per minute assuming 100% volumetric efficiency. Assuming 90% volumetric efficiency a 351 cubic inch motor will inhale air at the rate of 548 cfm at 6000 rpm or at the rate of 639 cfm at 7000 rpm. However, as the volumetric efficiency of a motor improves the intake manifold vacuum at wide open throttle shall decrease. The intake manifold pressure of a motor with 100% volumetric efficiency is theoretically equal to atmospheric pressure at wide open throttle. The airflow rating of carburetors is measured at a fixed depression, such as 1.5 inches of mercury in the case of Holley carburetors. If the depression across a Holley carburetor is less than 1.5 inches of mercury at wide open throttle it will not flow the amount of air it is rated at, the motor shall require a carburetor with a larger rating than what we calculated in order to supply adequate airflow at 6000 or 7000 rpm. The reason for this is not because the motor demands more air flow than what we calculated but because the carburetor, which is rated at a depression of 1.5 inches of mercury, flows less air if the depression is less than 1.5 inches of mercury; in other words the flow rating of a carburetor as determined at 1.5 inches of mercury becomes less relevant as the volumetric efficiency of a motor increases. Both the 351C 2V and the 351C 4V have higher volumetric efficiency than the popular in-line-valve V8s people are more familiar with; at wide open throttle the vacuum in their intake manifolds will drop lower than it does in those other V8s if the carburetor is large enough to allow it. This is the reason larger carburetors are recommended for the Cleveland engine series. If an owner allows the popular literature to influence their choice in carburetors, they shall end up strangling their Cleveland motor with a carburetor that is too small. On top of that the 351C 4V is capable of operating over an extraordinarily wide power band, certainly wider than any other OHV engine from its era. The first 351C 4V performance manifolds designed by Ford were designed for list #4575 Holley Dominator carburetors (1050 cfm)! Ford’s earliest carburetor recommendations also included the Holley 850 cfm double pumper. The 351 Cleveland engines require carburetors designed for engines having higher volumetric efficiency and in the case of the 351C 4V a wide power band too. The usual carburetor choices for a 351C 2V usually range from 650cfm to 750cfm; for the 351C 4V those choices usually range from 750cfm to 850cfm. None of these carburetors are too big for a 351C street motor, especially if they are equipped with annular booster venturis. With a 351C 4V street motor it is a challenge to find a carburetor that performs well at low rpm while also being large enough to take advantage of the WOT (wide open throttle) volumetric efficiency of that motor. Annular booster venturis atomize fuel better and provide a stronger fuel metering signal at low air velocity. In other words, annular booster venturis benefit the low rpm and mid-rpm performance of a motor in the same manner as the smaller primary throttle bores of a spread bore carburetor. These attributes make annular booster venturis popular for improving the low rpm operation of performance engines, where they have earned a reputation for improving torque, horsepower and throttle response at low engine speeds. However the improvement in fuel atomization distributes fuel more consistently throughout an intake manifold, resulting in more consistent fuel/air ratio from cylinder to cylinder, therefore annular booster venturis actually improve torque and horsepower across a motor's entire power band; and they improve fuel economy too! The only drawbacks of annular booster venturis include their larger physical size (which reduces the airflow capability of a carburetor by a relatively small amount) and their greater cost of manufacture. Mechanical secondary/annular booster carburetors featuring street calibration and electric chokes *Demon Carburetors #1282020 - 650 cfm - Speed Demon, mech. secondary, elec. choke kit #421440 *Demon Carburetors #1402020 - 750 cfm - Speed Demon, mech. secondary, elec. choke kit #421440 *Demon Carburetors #1563020 - 850 cfm - Speed Demon, mech. secondary, elec. choke kit #421440 *Holley #0-9379 - 750 cfm - Competition Series, mech. secondary, choke horn equipped *Holley #0-9380 – 850 cfm - Competition Series, mech. secondary, choke horn equipped *Quick Fuel Technologies (QFT) #SS-650-AN – 650 cfm – SS Series, mech. secondary, electric choke *Quick Fuel Technologies (QFT) #SS-750-AN – 750 cfm – SS Series, mech. secondary, electric choke Vacuum secondary/ annular booster carburetors featuring street calibration and electric chokes *Demon Carburetors #1282020VE - 650 cfm - Speed Demon, vac. secondary, electric choke *Demon Carburetors #1402020VE - 750 cfm - Speed Demon, vac. secondary, electric choke *Demon Carburetors #1563020VE - 850 cfm - Speed Demon, vac. secondary, electric choke *Summit Racing #M08600VS - 600 cfm – vac. secondary, electric choke *Summit Racing #M08750VS - 750 cfm – vac. secondary, electric choke Vacuum secondary/down-leg booster carburetors featuring street calibration and electric chokes *Quick Fuel Technologies (QFT) #SS-680-VS - 680 cfm – SS Series, vac. secondary, electric choke *Quick Fuel Technologies (QFT) #SS-735-VS - 735 cfm – SS Series, vac. secondary, electric choke *Quick Fuel Technologies (QFT) #SS-780-VS - 780 cfm – SS Series, vac. secondary, electric choke Edited June 21, 2013 by RacerX formatting Quote Share this post Link to post Share on other sites
RogerC 136 Report post Posted June 21, 2013 (edited) From the DeTomaso Internet Community, an article in a sticky by George Pence http://pantera.infopop.cc/eve/forums/a/tpc/f/5650045562/m/319104265 Four Barrel Carburetors At 6000 rpm a 351 cubic inch motor would theoretically inhale 609 cubic feet of air per minute if the volumetric efficiency were 100%. At 7000 rpm the same motor would inhale 710 cubic feet of air per minute assuming 100% volumetric efficiency. Assuming 90% volumetric efficiency a 351 cubic inch motor will inhale air at the rate of 548 cfm at 6000 rpm or at the rate of 639 cfm at 7000 rpm. However, as the volumetric efficiency of a motor improves the intake manifold vacuum at wide open throttle shall decrease. The intake manifold pressure of a motor with 100% volumetric efficiency is theoretically equal to atmospheric pressure at wide open throttle. The airflow rating of carburetors is measured at a fixed depression, such as 1.5 inches of mercury in the case of Holley carburetors. If the depression across a Holley carburetor is less than 1.5 inches of mercury at wide open throttle it will not flow the amount of air it is rated at, the motor shall require a carburetor with a larger rating than what we calculated in order to supply adequate airflow at 6000 or 7000 rpm. The reason for this is not because the motor demands more air flow than what we calculated but because the carburetor, which is rated at a depression of 1.5 inches of mercury, flows less air if the depression is less than 1.5 inches of mercury; in other words the flow rating of a carburetor as determined at 1.5 inches of mercury becomes less relevant as the volumetric efficiency of a motor increases. Both the 351C 2V and the 351C 4V have higher volumetric efficiency than the popular in-line-valve V8s people are more familiar with; at wide open throttle the vacuum in their intake manifolds will drop lower than it does in those other V8s if the carburetor is large enough to allow it. This is the reason larger carburetors are recommended for the Cleveland engine series. If an owner allows the popular literature to influence their choice in carburetors, they shall end up strangling their Cleveland motor with a carburetor that is too small. On top of that the 351C 4V is capable of operating over an extraordinarily wide power band, certainly wider than any other OHV engine from its era. The first 351C 4V performance manifolds designed by Ford were designed for list #4575 Holley Dominator carburetors (1050 cfm)! Ford’s earliest carburetor recommendations also included the Holley 850 cfm double pumper. The 351 Cleveland engines require carburetors designed for engines having higher volumetric efficiency and in the case of the 351C 4V a wide power band too. The usual carburetor choices for a 351C 2V usually range from 650cfm to 750cfm; for the 351C 4V those choices usually range from 750cfm to 850cfm. None of these carburetors are too big for a 351C street motor, especially if they are equipped with annular booster venturis. With a 351C 4V street motor it is a challenge to find a carburetor that performs well at low rpm while also being large enough to take advantage of the WOT (wide open throttle) volumetric efficiency of that motor. Annular booster venturis atomize fuel better and provide a stronger fuel metering signal at low air velocity. In other words, annular booster venturis benefit the low rpm and mid-rpm performance of a motor in the same manner as the smaller primary throttle bores of a spread bore carburetor. These attributes make annular booster venturis popular for improving the low rpm operation of performance engines, where they have earned a reputation for improving torque, horsepower and throttle response at low engine speeds. However the improvement in fuel atomization distributes fuel more consistently throughout an intake manifold, resulting in more consistent fuel/air ratio from cylinder to cylinder, therefore annular booster venturis actually improve torque and horsepower across a motor's entire power band; and they improve fuel economy too! The only drawbacks of annular booster venturis include their larger physical size (which reduces the airflow capability of a carburetor by a relatively small amount) and their greater cost of manufacture. Mechanical secondary/annular booster carburetors featuring street calibration and electric chokes *Demon Carburetors #1282020 - 650 cfm - Speed Demon, mech. secondary, elec. choke kit #421440 *Demon Carburetors #1402020 - 750 cfm - Speed Demon, mech. secondary, elec. choke kit #421440 *Demon Carburetors #1563020 - 850 cfm - Speed Demon, mech. secondary, elec. choke kit #421440 *Holley #0-9379 - 750 cfm - Competition Series, mech. secondary, choke horn equipped *Holley #0-9380 – 850 cfm - Competition Series, mech. secondary, choke horn equipped *Quick Fuel Technologies (QFT) #SS-650-AN – 650 cfm – SS Series, mech. secondary, electric choke *Quick Fuel Technologies (QFT) #SS-750-AN – 750 cfm – SS Series, mech. secondary, electric choke Vacuum secondary/ annular booster carburetors featuring street calibration and electric chokes *Demon Carburetors #1282020VE - 650 cfm - Speed Demon, vac. secondary, electric choke *Demon Carburetors #1402020VE - 750 cfm - Speed Demon, vac. secondary, electric choke *Demon Carburetors #1563020VE - 850 cfm - Speed Demon, vac. secondary, electric choke *Summit Racing #M08600VS - 600 cfm – vac. secondary, electric choke *Summit Racing #M08750VS - 750 cfm – vac. secondary, electric choke Vacuum secondary/down-leg booster carburetors featuring street calibration and electric chokes *Quick Fuel Technologies (QFT) #SS-680-VS - 680 cfm – SS Series, vac. secondary, electric choke *Quick Fuel Technologies (QFT) #SS-735-VS - 735 cfm – SS Series, vac. secondary, electric choke *Quick Fuel Technologies (QFT) #SS-780-VS - 780 cfm – SS Series, vac. secondary, electric choke Edited June 21, 2013 by RacerX formatting Quote Share this post Link to post Share on other sites
fvike 173 Report post Posted June 22, 2013 Good stuff RacerX! :thumbup1: Quote Share this post Link to post Share on other sites
fvike 173 Report post Posted June 22, 2013 Good stuff RacerX! :thumbup1: Quote Share this post Link to post Share on other sites
Max Power 74 Report post Posted June 24, 2013 Here I was gonna say Clevelands breathe a little better than most V-8s and that those charts for CFM never measure the rate of acceleration, only the airflow required to maintain rpm, and RacerX posts stuff far better than I could have said. 570 is just too damn small. 670 is probably ideal for stock variety street use. 770 will work pretty well on a stock 4v car, and is the minimum if you are going to mod it up. Quote Share this post Link to post Share on other sites
Max Power 74 Report post Posted June 24, 2013 Here I was gonna say Clevelands breathe a little better than most V-8s and that those charts for CFM never measure the rate of acceleration, only the airflow required to maintain rpm, and RacerX posts stuff far better than I could have said. 570 is just too damn small. 670 is probably ideal for stock variety street use. 770 will work pretty well on a stock 4v car, and is the minimum if you are going to mod it up. Quote Share this post Link to post Share on other sites
Chris'69Mach 23 Report post Posted June 24, 2013 Thanks RacerX for clarifying it up with your article. I ordered http://www.jegs.com/i/Holley/510/0-80770K/10002/-1?parentProductId and get it tomorrow. I would like to add that I have a 1970 351 Cleveland with the #4 stamped on the heads and other sources I have personally talked to said that the above carb will be just fine with the Cleveland. Quote Share this post Link to post Share on other sites
Chris'69Mach 23 Report post Posted June 24, 2013 Thanks RacerX for clarifying it up with your article. I ordered http://www.jegs.com/i/Holley/510/0-80770K/10002/-1?parentProductId and get it tomorrow. I would like to add that I have a 1970 351 Cleveland with the #4 stamped on the heads and other sources I have personally talked to said that the above carb will be just fine with the Cleveland. Quote Share this post Link to post Share on other sites
DocWok 30 Report post Posted November 8, 2014 It's refreshing to see the comments from 'RacerX' Somebody that actually does know what they are talking about. Quote Share this post Link to post Share on other sites
1969_Mach1 333 Report post Posted November 8, 2014 Well put RacerX. Too often the size of a carb is solely based on the simple math of calculating cfm at the estimated max RPM without any other considerations. The result is a carb that works but is slightly too small. Finally, somebody also mentioned the benefits of annular boosters as well. Holley use to have an online carb selector that considered a few other factors as well and was a little more thorough. Quote Share this post Link to post Share on other sites
