Help picking out carb...
Thread Starter
Instructor
Joined: Oct 2007
Posts: 162
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Help picking out carb...
Hi, i just pulled my 1977 Corvette Out of winter storage a little early and figured id fix it up for show season... Has an edelbrock 600cfm carb thats 6 years old and seems to dump alot of fuel on acceleration... im looking for a nice out of the box carb that doesent require adjustment other than turning a screwdriver.. My engine is:
1977 L82 Block
Trick Flow 23 degree aluminum heads
Comp Cams 252H and full roller setup
Edelbrock Intake
I need some decent fuel economy and performance out of this does anyone have any ideas??
1977 L82 Block
Trick Flow 23 degree aluminum heads
Comp Cams 252H and full roller setup
Edelbrock Intake
I need some decent fuel economy and performance out of this does anyone have any ideas??
Melting Slicks
Joined: Mar 2006
Posts: 2,465
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From: Orange Park Fl
Melting Slicks
Joined: May 2007
Posts: 3,246
Likes: 4
From: Bay Area CA
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No probelms on decel. The fuel line location and the accellerator linkage did not require any changes from the POS Q-jet I removed. Holley tech said it was enough carb for this engine. I thought it might be too small. It runs great. Highly recommend it.
Melting Slicks
Joined: Mar 2006
Posts: 2,465
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From: Orange Park Fl
The first problem with Holleys is their current quality control (read the previous posts). It's hit or miss if you will get one that works.
The second problem with Holleys (and other aftermarket carbs) is that they are too simple. You may not consider this a problem, until you realize that its simplicity makes you choose between performance and fuel economy. Either way, there will be days you curse that carb. The Quadrajet is a more refined unit that can be tuned for optimum fuel economy without compromising WOT performance. In this area it is without peer. God bless, Sensei
The second problem with Holleys (and other aftermarket carbs) is that they are too simple. You may not consider this a problem, until you realize that its simplicity makes you choose between performance and fuel economy. Either way, there will be days you curse that carb. The Quadrajet is a more refined unit that can be tuned for optimum fuel economy without compromising WOT performance. In this area it is without peer. God bless, Sensei
Melting Slicks
Joined: May 2007
Posts: 3,246
Likes: 4
From: Bay Area CA
I just put a Holley 6210 on my 68 427/390 yesterday. It is a mechanicial secondary (double pump) 650 CFM spreadbore carb. It is a bolt in replacement for the Quadrajet. It really livened up my car. Excellent throttle response. Great low and mid-range torque. Jumped on it in 1st gear and was going sideways No probelms on decel. The fuel line location and the accellerator linkage did not require any changes from the POS Q-jet I removed. Holley tech said it was enough carb for this engine. I thought it might be too small. It runs great. Highly recommend it.
No probelms on decel. The fuel line location and the accellerator linkage did not require any changes from the POS Q-jet I removed. Holley tech said it was enough carb for this engine. I thought it might be too small. It runs great. Highly recommend it.
take it to about 20 and step on the brakes- hard neaqr to actual lock up hard, swee if the engine wants to lug and drops RPMs. mine will drop to 100 rmps, and die, if you don't feather the throttle. otherwise it's a good carb.
The first problem with Holleys is their current quality control (read the previous posts). It's hit or miss if you will get one that works.
The second problem with Holleys (and other aftermarket carbs) is that they are too simple. You may not consider this a problem, until you realize that its simplicity makes you choose between performance and fuel economy. Either way, there will be days you curse that carb. The Quadrajet is a more refined unit that can be tuned for optimum fuel economy without compromising WOT performance. In this area it is without peer. God bless, Sensei
The second problem with Holleys (and other aftermarket carbs) is that they are too simple. You may not consider this a problem, until you realize that its simplicity makes you choose between performance and fuel economy. Either way, there will be days you curse that carb. The Quadrajet is a more refined unit that can be tuned for optimum fuel economy without compromising WOT performance. In this area it is without peer. God bless, Sensei
Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
There are plenty of them sitting in junk yards and on ebay dirt cheap (buy two or three!). Don't buy a rebuilt one, it will probably be garbage. Buy "Rochester Carburetors" by Doug Roe. Get Lars' tuning paper. Read them! Then buy a good set of rubber gloves, a small galvanized tub, a gallon of laquer thinner and a carb kit. The next day you will be on your way to Q-jetopia. God bless, Sensei
Drifting
Joined: Sep 2004
Posts: 1,959
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From: North Bend Ohio
Drifting
Joined: Apr 2006
Posts: 1,911
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From: gold coast queensland
your holley is brand new? one of your mixture scres doesnt work? i would be taking it back? looking into that ! to fix the thing dieing i would take it off pull the bowls off it and give it a good clean , inspect and hit it with some compressed air in the ports. sounds like you may have a blockage.
Melting Slicks
Joined: May 2007
Posts: 3,246
Likes: 4
From: Bay Area CA
Yea, it looks like i'll be going that route (pull and clean) It's about 1.5 years old, but only has 20h on it. Just got it finished, after 18 months, thanks to some help from here at the forum. When i first put the carb on, i ran it with some pretty old gas, and with the tank low on fuel with only the filter in the carb. I'll see if it helps. I like the carb though. mechanicle secondaries 
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
About anything you buy off the shelf is going to have problems. Off-shore rebuild outfits tear 'em apart and throw 'em back together. As long as they look good, they put 'em in a box and sell them.
Do yourself a favor and rebuild what you have. From your description, I'm guessing it is a square-bore AFB design carb [on a similar designed intake]. If it happens to be an Edelbrock Q-jet [rated at 600cfm by Edelbrock], that's even better...because the Q-jet will actually flow much better than that.
If you rebuild it, you will learn a lot about the carb and how it works. You will also have the opportunity [and obligation] to clean out all of the passages and re-adjust all of the settings so that you KNOW it will be correct and work properly. That is much better than what you would get from of a rebuilder.
Do yourself a favor and rebuild what you have. From your description, I'm guessing it is a square-bore AFB design carb [on a similar designed intake]. If it happens to be an Edelbrock Q-jet [rated at 600cfm by Edelbrock], that's even better...because the Q-jet will actually flow much better than that.
If you rebuild it, you will learn a lot about the carb and how it works. You will also have the opportunity [and obligation] to clean out all of the passages and re-adjust all of the settings so that you KNOW it will be correct and work properly. That is much better than what you would get from of a rebuilder.
Cruising
Joined: Sep 2005
Posts: 11
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Hey, I also have a 77, with 383 stroker. I have run the 650 street demon with flawless performance. It does have electric choke and starts instantly even after sitting a month or so. this is a low 12 second car and will achieve 15-16 mpg on the hwy.with 355 gears. So far this has been the best carb I've run yet.....Good luck!!!!