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When Autolite was purchased by Allied Signal there carburetors had long before left to become Motorcraft units. The Summit carb is, for all intents and purposes, a repop of the Holley 4010. As far as to the lack of success of the 4010, here is a snippet of its history by a former Holley employee:


The 4010 was released in 1986 as a response to the perceived threat from the re-released Carter AFB. The idea was that we'd have a polished aluminum finish and no gaskets below the fuel level - just like the Carter. The carbs were always intended as street use only - not for competition, and only a couple of boat engine manufacturers tried them - notably Volvo Penta.

They were not bad carbs, but there was never a real reason to buy one either. They were limited in power output (small metering passages), still had the power valves that everybody hated (for all the wrong reasons), and actually cost more to make and thus sell.
how did you get the Colored (Purple) text ?
 

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I just finished installing the 500cfm summit carb on my 65 yesterday. Haven’t driven it too much yet but so far so good. Idles great and has very snappy throttle response. It replaced a 600 cfm Edelbrock that I was never able to get tuned quite right. Next week I’ll do an mpg test.
 

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I just finished installing the 500cfm summit carb on my 65 yesterday. Haven’t driven it too much yet but so far so good. Idles great and has very snappy throttle response. It replaced a 600 cfm Edelbrock that I was never able to get tuned quite right. Next week I’ll do an mpg test.
& you'd probably like the snappy throttle response of an old gas wars era 4360 450cfm Economaster Mech Secondaries even further !.
Cheers.
Then there's always a Quadrajet Robbed off a chev 305ci if your running a stick shift. :p
 

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I like the Holley carbs, more so the older ones and honestly they look more period correct. With some changes to them that most can do they work very well. Add an O2 bung and fine tune them and they will work very well and get some good mileage to boot And when you get the AFR correct it will run the best..The 600 cfm vacuum secondary carb is an great choice for most of us here and you can get an older used one on eBay for a decent price and add a few bucks to it and it will be a good piece IMO...
 

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65 Fastback 289 4 spd, 65 convertible 5.0L 5 spd. 3.73 8.8
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A 302 essentially is a 289. Besides, he's currently got a 600 cfm carburetor on there, dropping down to a 570 cfm isn't going to make much of a difference, if at all. Especially if his 302 is stock or a mild build. Guys over-carb a motor all the time, not a good idea, especially for a street car.
Im sorry, I was replying to wrong thread. You are right it will be fine.
 

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Discussion Starter #28 (Edited)
The issue with the Autolite 4100 currently on it is the age old "Struggles to Start When Warm". I had the same issue before and after rebuild. I have the floats set to level when in the up position (about .480 below the top of the base). Air fuel mixture screws are 1 1/2 turns out from seated close. The car fires up and runs great when cool. It runs great when hot, just hard to start like it's flooded after it warms up. I have a steel fuel line from the fuel pump to carb, except a 2" piece of rubber to connect it to the fuel filter. I have the carb on a 1/2" spacer between the carb and intake. If I could figure out the hard start when warm issue, I'd keep the Autolite. Below is a pic of what I have. I also have all the emission lines connected as in the image below and the Distributor Vacuum Control Valve is New. The dwell is set to 26 degrees. The timing is set to 6 BTDC. Spark plugs are all new set to .032 gap. I have not tested the door on the air inlet to see what that does yet, if that could be an issue?
Any suggestions to what could be the issue with the warm start is appreciated. Also if anyone knows how the Air Cleaner Vacuum Overide is suppose to function is appreciated.
748527

748528
 

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I know someone who just ordered a 363 from Ford Strokers. Woody, the owner said it'll make over 500 go. It uses a 650 cfm. Why do you say 570 cfm is too small for a stock 302?
Wholeheartedly agree. And it's because people will over-carb the piss out of their motors thinking it will get them more horsepower. On a stock or mildly modified street car with a 302 there's no reason to go above 570. Shoot, a 500 or 550 cfm carb would work fine as well, also mentioned about by another member. And I think a 650 cfm carb is a great choice for your friend, especially if it's mostly a street car. He could bump up to a 750 if he really wanted to, might get him another 10-15hp on the engine dyno, but it's not needed.
 

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Wholeheartedly agree. And it's because people will over-carb the piss out of their motors thinking it will get them more horsepower. On a stock or mildly modified street car with a 302 there's no reason to go above 570. Shoot, a 500 or 550 cfm carb would work fine as well, also mentioned about by another member. And I think a 650 cfm carb is a great choice for your friend, especially if it's mostly a street car. He could bump up to a 750 if he really wanted to, might get him another 10-15hp on the engine dyno, but it's not needed.
I would like to add that it's also pretty common for people to run their carburetors too rich. Sure, you can bolt on a carb and say, "Hey, it runs fine!". But that doesn't mean it's right. Most any application will require some tuning. There are just so many variables: altitude, cubic inches, cam profile, exhaust system, cylinder head flow, etc. The chances of an out of the box carb being optimal are pretty low.

While 1960s cars certainly didn't run as cleanly as new cars, when they didn't need a tune-up, they didn't spew raw gasoline from the exhaust. Almost every time I'm driving behind a classic car, my eyes are watering from raw, unburned gasoline which means the carburetor is way too rich. It's bad for the environment, bad for fuel economy, bad for the wallet and also bad for the engine to run too rich.

Therefore, I always suggest ordering a calibration kit with whatever carburetor you choose. Try different jet sizes, different secondary springs (if vacuum secondary), different metering rods (if equipped). Not only will the engine run better, it will be more fun to drive, perform better and you'll learn a lot about how carburetors work. And yeah, you might even have to richen the mixture.
 

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I would like to add that it's also pretty common for people to run their carburetors too rich. Sure, you can bolt on a carb and say, "Hey, it runs fine!". But that doesn't mean it's right. Most any application will require some tuning. There are just so many variables: altitude, cubic inches, cam profile, exhaust system, cylinder head flow, etc. The chances of an out of the box carb being optimal are pretty low.

While 1960s cars certainly didn't run as cleanly as new cars, when they didn't need a tune-up, they didn't spew raw gasoline from the exhaust. Almost every time I'm driving behind a classic car, my eyes are watering from raw, unburned gasoline which means the carburetor is way too rich. It's bad for the environment, bad for fuel economy, bad for the wallet and also bad for the engine to run too rich.

Therefore, I always suggest ordering a calibration kit with whatever carburetor you choose. Try different jet sizes, different secondary springs (if vacuum secondary), different metering rods (if equipped). Not only will the engine run better, it will be more fun to drive, perform better and you'll learn a lot about how carburetors work. And yeah, you might even have to richen the mixture.
Yeah, not many probably realise how sharp a leaner running carb can be: sharper throttle response & driveability & often top end power.
Good points.
IMG_20200316_190843.jpg
 

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I'd go with a Holley 570 Street Avenger on yours. It's not too expensive, the one I had came ready to go right out of the box and it has a lifetime warranty on it. Hard to beat in my opinion.
This is what I put on my 66. Electric choke. Went on easy, was simple to tune, and has been problem free for 6 months.
 

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<mark>highlighted text</mark>.</p> interesting ,but I don't speak Greek <mark>highlighted text</mark>.</p>
LOL.

For example...

Crap....

Pretend the "(" and ")" are actually "[" and "]"...

(color=magenta) Now what I type would appear in magenta until I end it with this.... (/color).
 

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I installed a Quick Fuel SL-600-VS. on my 64.5 289 D code and have had nothing but problems with hard cold start, bogging down when running cold. Also poor mileage and stumble on high end. Going back to the oiginal Autolite.
 
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