Carb CFM size
Drifting
Joined: Mar 2009
Posts: 1,253
Likes: 4
From: East Wenatchee (2hours from n e where) WA
For a docile little daily driver you should probly go with a 600 vac secondary. BUT it sounds like you like to put your foot in it with some turn n burn thrown in. Id use a 650 double pumper the center hung floats will turn with out any problems. You need to find out if the manifold is square or spread bore. Pics?
Drifting
Joined: Jun 2010
Posts: 1,781
Likes: 15
From: Oxford Ohio
Regardless how enormous your motor, manifold, etc., if you are normally, like the vast majority of us, driving no more than 5-6000 rpm, a nice lightweight 650 cfm Holley is perfect.[/QUOTE]
You can get poor performance from excess fuel dumping that's not needed
It would be interesting to know what radical he is talking about?
You can get poor performance from excess fuel dumping that's not needed
It would be interesting to know what radical he is talking about?
Thread Starter
Advanced
Joined: Sep 2012
Posts: 86
Likes: 2
From: Rochester NY
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
750 CFM Four Barrel Street Carburetor PART #: 0-80508S If you drive it hard and wind it tight.
650 CFM Four Barrel Street Carburetor PART #: 0-80783C If you drive it normally and do not crank it past 6000-6500 RPM. This carb has replacable jets in both primary and secondary. You will have to tune either one of these to your engine. No carb is ever absolutely correct out of the box. Best thing is these are easily tuned and parts availability is great.
650 CFM Four Barrel Street Carburetor PART #: 0-80783C If you drive it normally and do not crank it past 6000-6500 RPM. This carb has replacable jets in both primary and secondary. You will have to tune either one of these to your engine. No carb is ever absolutely correct out of the box. Best thing is these are easily tuned and parts availability is great.
Last edited by 63mako; Nov 27, 2012 at 11:16 AM.
Thread Starter
Advanced
Joined: Sep 2012
Posts: 86
Likes: 2
From: Rochester NY
Thank guys,
I called Holley technical and the guy thinks that the 650 or Avenger 670 is the right carb. He said that it will be quicker off the line, but slower in the mid range. He also said to get vacuum secondaries and no double pump. He said the double pump is overkill unless I'm at WOT. He said the 650 would be more driver friendly.
He made a good argument for the 650. Any counterpoints to this that anyone can think of?
I called Holley technical and the guy thinks that the 650 or Avenger 670 is the right carb. He said that it will be quicker off the line, but slower in the mid range. He also said to get vacuum secondaries and no double pump. He said the double pump is overkill unless I'm at WOT. He said the 650 would be more driver friendly.
He made a good argument for the 650. Any counterpoints to this that anyone can think of?
Burning Brakes
Joined: Apr 2007
Posts: 1,039
Likes: 62
From: Kona Hawaii
Carbs are like *****! You think bigger is better until you realize you really can't use all you got to play with.So then you settle for a nice and perfect medium size....650cfm is just about right...
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Drifting
Joined: Jun 2011
Posts: 1,704
Likes: 27
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Verdad Gallardo
Had a 1976 L-82, 4-sp
Joined: Mar 2011
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From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
I actually have a 650 Holley DP and is street driven only (for now, anyway). The car has very good manners and I don't miss a vacuum secondary carb whatsoever. I'll agree with those that recommend a 650. Your engine can only "pump" so much for its size and anything over 650 is over kill for a 350 turning less than 6000 rpm.
Had a 1976 L-82, 4-sp
Joined: Mar 2011
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From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
Melting Slicks
Joined: Aug 2012
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From: Titusville Florida
Melting Slicks
Joined: Aug 2012
Posts: 3,487
Likes: 83
From: Titusville Florida
Thread Starter
Advanced
Joined: Sep 2012
Posts: 86
Likes: 2
From: Rochester NY
750 CFM Four Barrel Street Carburetor PART #: 0-80508S If you drive it hard and wind it tight.
650 CFM Four Barrel Street Carburetor PART #: 0-80783C If you drive it normally and do not crank it past 6000-6500 RPM. This carb has replacable jets in both primary and secondary. You will have to tune either one of these to your engine. No carb is ever absolutely correct out of the box. Best thing is these are easily tuned and parts availability is great.
650 CFM Four Barrel Street Carburetor PART #: 0-80783C If you drive it normally and do not crank it past 6000-6500 RPM. This carb has replacable jets in both primary and secondary. You will have to tune either one of these to your engine. No carb is ever absolutely correct out of the box. Best thing is these are easily tuned and parts availability is great.
