I never had any use for Holley 4000 carburetors. Back in the day, we called them "flaming infernos".  With the fuel bowl up high like that, I can understand why. I understand why someone would want to keep an old car stock.    I keep all the stock parts to my TBird in case a new owner might want to put them back on.  It's quite a pile by now.    I have had engine backfires with a Holley 4100 too.  It wasn't the fault of the carburetor. Thankfully, I have never had one catch fire.  I will say I have seen a  lot of cars with scorched and bubbled hoods.

I have had all kinds of street and race cars in my life.  One ran consistent 10.60 125 mph quarters.  I have never had any carburetor perform better than a Holley.  People tell me they leak.  If you don't use quality gaskets they do. In my opinion, nothing feels better in the seat of your pants. To be honest, I have never owned a supercharged car and my drive around cars are all injected or turbo charged.  As Warren Johnson once said, "You can't find a carburetor on a lawn mower these days".    With a Holley, I know what to expect and they deliver.

"Back in the day" Whenever we encountered one of those Holley 4000's (we called 'em 'Helmet Heads') we threw them in the scrap pile! A bad design!



"FREE SAMPLE"

Greetings and a great new year to all:   "Bach in the day," I made them work. I knew they functioned OK when everything was new and therefore could function OK again. With a good tune, a quality 4000 kit  installed and adjusted properly, the 4000 was OK.  Often it wasn't an option to install updated parts like a modern Holley and dual advanced distributor on someone's car I was repairing.  As a kid I got a lot of satisfaction doing this in the 60's and was quite busy.  However, my car or my buddies cars got the up-grades of what ever we could afford at the time.


64F100 57FAIRLANE500

"Back in my Day", no one that I knew had money.  There weren't any doctors or lawyers living in my neighborhood.  The first new car I ever sat in was my in-laws Olds 88 four door.  When I hear today's politicians talk about income inequality it makes me laugh.  No one gives you anything unless they want something in return, especially the government.  We made do with what we had.  We dragged home old cars just for the engines.  A quick Gunk treatment and we were good to go.   In the sixties when I graduated from high school the guys with money were construction workers making $6 an hour.  Hard to believe that was big money back then. 

I wouldn't trade anything for those memories.  Like the day I blew up an engine when my coat hanger throttle linkage stuck wide open.  Or the time I changed intake manifolds using Christmas lights for an extension cord.  Or the time my best friend won the trophy at the local air port drag strip with a 56 Ford Y-Block when the 409 55 scruby he was running missed every gear there was.

Sorry for the nostalgia.   It's a big part of the Y-Block experience.

I still run the stock 4000 on my 56 Bird.  Had it redone by some one who knew what he was doing (not just some average guy who rebuilds carbs) and it runs fine.  Ted converted it for me to run with a 57 distributor.


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Backfires from the dual quad Y engines was no more common than the rest of the engines from that era that used breaker point ignitions.  The fire problem though was more notable with the Teapot carbs whether it was a single four or the dual quads than with the other carbs available back then.  Part of that comes from the propensity of those carbs to leak fuel from either the large threaded screw that holds the needle and seat in place or the ‘O’ rings around the pair of secondary fuel transfer tubes.  If either of the anti-siphon holes on the fuel reservoir cover stopped up, then the fuel would siphon down into the rear bowls when the engine was stopped.  In the case of a backfire, then that puddle of fuel just ignited and burned.
 
I personally like those Holley model 2140 and 4000 carbs and with a modern ignition they are trouble free.  A matching pair works really well on a dual quad setup simply due to them only being about 400 cfm each.  Running just a single one typically has most engines under carbureted  as even a 272 perks up when a larger carburetor is put on in place of a Teapot.  The Teapot carbs can be picky to get the jetting just right with ethanol laden fuel though as the factory jetting was pretty much spot on with ‘pure’ gasoline.  If you want to learn about carburetor circuitry, the 1953 & 1954 Holley model 2140 carbs are quite simple and the circuitry is easy to follow when tracing the fuel flows through them.  Those model 2140 carbs are about 350 cfm so two of them on a mild Y with a dual quad setup makes for a spirited driver.
 
Here’s a picture of the 1953/1954 model 2140 carbs on a dual quad intake.  Observe that the choke plate is actually located at the top of the venturie rather than at the front of an enclosure like the 1955-1957 model 4000 Teapot carbs.
  

There’s also nothing wrong with the mid-Fifties GM Carter and Rochester 4V carbs on the dual quad setups but finding a matching pair is becoming more difficult.  All carburetors are simply controlled fuel leaks where some just do a better of job of controlling those leaks than others.

Lorena, Texas (South of Waco)

This thread topic is emblematic of this Forum.  Florida Phil's initial question has sparked multiple members to engage in a wide ranging discussion and exchange of related, in-depth, information.

Thanks to our sage moderators and members for all that you bring and share here.  Like myself, I'm sure that many benefit from your wisdom, experience, efforts and generosity.  Kudos to all!  

Best Wishes to all for a Happy and Healthy New Year!
Charlie


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

This forum is a great resource.  Most of this information died with the people who raced, worked on and serviced these vehicles. The Internet lives forever.

I have run dual quads on my T'bird since 1972. It took a while to get them right. Custom fabbing the linkage as I had no money to buy the T'bird linkage. On my last rebuild I milled a couple of adapters and mounted to G.M. Throttle bodies and fabbed up a new direct linkage running on the primaries of both. Rebuilt the throttle bodies, electric fuel pumps all to tolerate the ethanol in today's gas. Took a while to get the programming right on the accel gen 7 computer but it was all worth it. If I haven't driven the car Fo a few weeks still starts right up. It has wonderful low end response that it never had with the carbs, and with the air cleaner on it looks stock. Best of both worlds for the last 6-7 years.

Mike, still lovin his 57 t'bird after 53 years!