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Discussion Starter #1 (Edited)
I have an Edelbrock 1806 Thunder AVS 650 currently. I really think that it may be a bit too much carb for my engine. I am considering changing carburetors to an Autolite 4100. Is it possible to get one setup for having Edelbrock aluminum heads and a mild cam? My engine is built to make some power but is not radical.

I also can almost never just get in the car and turn the key and have it start. The only time this works is if its been driven and sits for a short while. When its cold I have to pump it 5 or more times and attempt to start at least 2 if not 3 times. After its been driven in the warmer weather it floods extremely easily.

The average fuel economy is about 16. I was hoping for better than that. Not that this car was built for that purpose, it would just be nice if it were better.

Where would be the best place to get a fresh Autolite carb? Would it be from Pony Carbs?

http://www.ponycarburetors.com/
 

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The larger of the 4100 was the 1.125 bore unit used on the 289HP, and 352/390/428 engines. Almost all of these were set up for the BB engine, so if you get one, make sure it's been recalibrated for your engine. The one used on the 289HP had a manual choke, on the Mustang.

The 4100 was the finest 4V carburetor ever made. Excellent response, easy to work on, no leaks, and with 4 annular discharge venturis, excellent mileage. I was getting up to 21 mpg highway on my stock A code 4V, which had the 1.085 version.

I know how you feel about Holleys. After 15 years of Holleys on my daily driver, I figure to go straight to heaven when I die.

Pony carbs does a replica of the 289HP carb, including the choke. Pricey, but nice.

 

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Discussion Starter #3 (Edited)
Thats what I was hoping to hear. What info do I need to have one calibrated?

I feel dumb for having to ask, but can I use and electric choke on the 4100? I already have it set up that way.

It looks like Pony offers 2 different ones. One has 1.08 and the other 1.12. If I do get one, the one to get is the 1.12 I guess. Like you said, they are pricey at 599 and 744 dollars. I wish it was more like 400-500.

The Edelbrock is a decent carb, I'm not going to knock it, but I just want something more consistant.

Is there another good source for a new 4100?
 

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Discussion Starter #5 (Edited)
I'm not entirely sure what CFM my engine really needs. Thoughts on that?

What fuel pressure do the Autolites like, will my Edelbrock fuel pump be fine?
 

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I've run both 4100s and the Edelbrock 500 cfm carb. IMO they are very similar in terms of driveability and performance. And Pony Carbs carburetors and service have been iffy. If you want better mileage and low end throttle response at a reduced price I would get the Edelbrock. If you watch ebay you can pick a barely used one at a significant discount from new.

And nothing could be easier in terms of tuning. Changing metering rods and stepup springs takes about 60 seconds.
 

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I'm not entirely sure what CFM my engine really needs. Thoughts on that?

What fuel pressure do the Autolites like, will my Edelbrock fuel pump be fine?
Stock fuel pump is plenty. The 500 cfm I had on my 289 HiPo pulled strong to 5500 rpm.
 

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Discussion Starter #8 (Edited)
The carb is only about 3 years old and has 5000 miles on it. I was looking into tuning my carb better. I have a calibration kit for it. I don't know alot about carbs since I have only had 2 vehicles with them and they were stock. Can I de-tune (if thats what you would even call it) the carb I have enough. I have already had to open up the 650 and partially rebuilt and clean it. I don't know why it got crudded up.

I have a new gas tank and all new fuel lines and 2 fuel filters. I did have an issue with too much fuel pressure because of the wrong pump, thats why I have the Edelbrock pump now. The Edelbrock fuel pump is about 2 years old and has probably 4000 miles on it.

Should I trade the Edelbrock 650 for a smaller Edelbrock?
 

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A 600 is right for a smallblock with upgraded cam. The stock fuel pump is just fine.
 

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Discussion Starter #10
Would I be better off with the Edelbrock Performer 600 than the Thunder AVS 650?
 

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67 coupe, 69 Sportsroof, 86 hatchback
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I lean more towards Edelbrock 500 cfm's with 302's. The original smaller 4100 was rated at 480cfm. Pretty much acclaimed to be about a perfect match for a stock to mild 289/302 that is street driven. I love the throttle response of a smaller carburetor. Now if you've got stuff like Trick Flow heads and/or in the habit of twisting it up to 6000 rpm on a regular basis then you'll probably be better served by 600 cfm.
I like Edelbrocks. But all I have seen tend to let the fuel drain back or evaporate after sitting a while. So you have to crank a weekend driver quite bit to get fuel back up to the carb. Flooding when hot sounds like something that can be cured with some adjusting. I'm in the habit of adjusting my chokes a bit rich for winter and a bit leaner come spring which helps with that too.
I have two Edelbrocks in service. A 500 on SWMBO's mild 5.0 and a 600 cfm on a moderate 351W.
 

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While I am a fan of 4100's, they are not generally for the tinkerer as parts like jets have few sources. That being said, you can dial just about any one of them in with proper jetting and fuel height. They ran 1.12's on the first 289's.
 

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Be very aware when dealing with John at Pony Carbs. I had one built for a customers car a few years ago, and it never ran very well at all. I called and asked what he thought was the problem, and he will always blame it on ignition timing or the fact that most people don't know what they are doing. He will also warn you that if you crack the carb open, the warranty will be void because he "seals" them and will know if they have been tampered with. I finally opened the carb, and it was full of debris, and the floats were set so that they were almost completely closed. There are no "secret" modifications done to the carb either like they describe in their literature. Bottom line, save your money, buy a used carb and rebuild it yourself.
 

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Did that fix it?

Be very aware when dealing with John at Pony Carbs. I had one built for a customers car a few years ago, and it never ran very well at all. I called and asked what he thought was the problem, and he will always blame it on ignition timing or the fact that most people don't know what they are doing. He will also warn you that if you crack the carb open, the warranty will be void because he "seals" them and will know if they have been tampered with. I finally opened the carb, and it was full of debris, and the floats were set so that they were almost completely closed. There are no "secret" modifications done to the carb either like they describe in their literature. Bottom line, save your money, buy a used carb and rebuild it yourself.
Falcon, I was about to drop a $500 bill to Pony for a concours rebuild. After you got the debris out and set the float levels, did it run right?
Bryan
 

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Falcon, I was about to drop a $500 bill to Pony for a concours rebuild. After you got the debris out and set the float levels, did it run right?
Bryan
It runs great now, but just in case you have a problem be ready for some attitude as customer service is horrible. On the plus side, the carb looks awesome, everything is replated and pretty.
 

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I have yet to use one, but I have run down everyone I could find who has, and nobody had a bad thing to say about them. They used several concepts from the 4100, such as the one-piece body with a top lid, so no leaking. They also used the compact front/rear float bowls, and even had annular discharge on the primary venturis, for better power and fuel economy. It does, however, use the same jets, pumps, cams, and diaphrams as the garden-variety Holley, for easy modification and tuning, which is rarely required. The current carb is actually a recreation, based on Summit collaborating with the original designer of the Holley carb. It has some upgrades, such as the downward angle of the fuel inlets, for better clearance on the fuel lines. I say recreation because apparently Holley destroyed the casting dies when they dropped production. Seems to be a very streetable, no-drama carb, which was what Holley intended. Also very reasonably priced.
 

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Would I be better off with the Edelbrock Performer 600 than the Thunder AVS 650?
I have the Edelbrock Performer #1406 (600 cfm, electric choke) on my 289. Milder build, but definitely more punch than stock (about 280hp at the crank). I haven't had a lick of trouble with the carb in about 10 years, although it's probably about due to be run through for ease of mind. Definitely runs a ton better than the Holley 650 double pumper than was on it.

I will agree 100% about the Edelbrocks getting dry, quick. If the car has been sitting at all, it takes 2-3 cranks while pumping to get it to fire, then it runs great. If its warm, all I have to do is blip the ignition and it fires right up. Also, getting the kickdown on my C4 was a royal pain, but a local tranny shop was finally able to make it work. All in all, I like my Edelbrock for the ease of operation (I'm an idiot when it comes to rebuilding carbs, etc.)

Hope this helps.
 

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Those Summit carbs have been intriguing me for a while now. I like how under the "application" tab Summit provides a CFM calculator. If you check it out keep in mind that stockish cars redline at about 6000 because the valves tend to float after that. Though you can rev one higher unless you have heads set up for racing with heavier valve springs, etc, it's a waste. Traditionally the THE most common DIY hotrodding mistakes are too big a carb and too radical a cam. Seems like somebody will always chime in on such cfm discussions saying how they are happily running some grossly oversized carb on their little stock engine and it goes faster than the space shuttle or something.
 

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The Summit carbs are nothing new, Holley intruduced them in the late 80's as the 4010, and the 4011. There may have been a few other part numbers as well. They ase all the regular Holley parts like jets. floats etc. The public could just not get used to a new Holley carb that didn't look like the old carbs, and they dis-continued them. They do still offer kits for them. The Summit carbs are the same 4010-4011 Holley carb under a private label, and I would bet that Holley makes the carbs. They do work great, and have the added benefit of the one piece gasket as well for no leaks.

The Summit brand 6AL ignition box is a private label box that is made by MSD in MSD's factory, it uses all the same components as well as the same instructions. There are generic alternatives in car parts as well.
 
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