It's time to get a new carburetor for my y-Block. The current 600 cfm Carter AFB  has seen better days and is leaking at the throttle shafts.   It has given 20 years service.

I have a mildly upgraded 272 Y Block in my '54 F100.  It has been balanced and rebuilt by Ted Eatonusing big valve heads and a mild cam upgrade. I am using the FORD ECZ-9425-B intake manifold.  It is used for cruising and towing a boat, soI don't want a fire breathing dragon, and fuel economy is nice. 

I am considering trying one of the Demon Fuel Systems  "Street Demon 625 cfm"  #1900 4 bbls.   Does anyone have any experience with thiscarb on a Y-block??  Does it have thelarge vacuum port for the Y-Block PCV system hose (The Carter has a big vacuum port in its base)?  Is this too much carb cfm for a 272?

Any other 4 bbl.  carbsI should be considering that offer simplicity with a combination of performanceand economy?

Thanks and regards, Jeff

Jeff Davis

'54 F-100 - 272 Y Block 
'57 Tunderbird Colonial White 312 Y Block
'57 Triumph 6T 650cc - my other Thunderbird

'56 F-350 FORD factory Script  Stakebed Dually - 292 Y Block

Wellington, Florida

How about a new AFB?

I've ran the Edelbrock 1450 AFB on a stock 292, on that same motor when I put the SN93 on it, and on a 320cid, with the blower. Re-jetted, of course. My F code motor has a highly modified a Holley, for boost, and it's been a pain. I've had Qjets on a number of OT motors that ran really well. I really like the AFB. If your's has a tag, and has been performing well for 20 years, you might buy a new one, or rebuild the old one. You know the jets, rods, springs, etc. Lots of fancy new carbs out there, but sometimes it's hard to beat the "drivability" of the old designs.


miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

The Summit 600 vac secondaries has had pretty good reviews

http://www.allfordmustangs.com/forums/classic-tech/326771-summit-racing-600-carburetor-review.html

https://www.youtube.com/watch?v=VPIGs85iyuE

South Australia

Jeff.  Welcome to the site.  I recently tested a #1900 Street Demon on a 308” Y and it runs well after rejetting.  Primaries were on the rich side but was easily corrected with the the Demon calibration kit.  There will be an article in the upcoming Y-Block Magazine #122 that goes into the 308” build and some of the particulars with the Street Demon that was tested.  The Demon has the necessary vacuum ports at its back to hook up the PCV valve.

Later this week a Summit 600 cfm carb will be run on a 292 with G heads and ECZ-B intake.  I’m currently waiting on some ignition parts for that engine before it can be started up and run in  I've had good results with those carbs on other engines so I don't see it being a problem on this one either.

Lorena, Texas (South of Waco)

Thanks for all the quick input, gentlemen.   I didn't know you could still buy an AFB.  Does Edelbrock own/manufacture the AFB still?    Am I right in thinking  Holley Performance owns Demon now??

Jeff Davis

'54 F-100 - 272 Y Block 
'57 Tunderbird Colonial White 312 Y Block
'57 Triumph 6T 650cc - my other Thunderbird

'56 F-350 FORD factory Script  Stakebed Dually - 292 Y Block

Wellington, Florida

Tuning a carb is not a big deal at all.  The key is to keep track of the changes you made so you can go back if you make a change that doesn't work.The Edelbrock will be most like the AFB but of the original carter AFBs i've seen, I would not say they are the same.  Very similar, but not the same.  If you get an Edelbrock, it comes with a great booklet going over the theory of operation and how to tune.  While it is geared toward the Edelbrock carb, much of the info is pretty general and can be applied to most carburetors.  It is also available for download from Edelbrock.



Lawrenceville, GA

A simple 390, 450, 465 Holley..? You'll have to make up a base for the hose.  Phil from RPM Ind  [east coast USA]  built a second hand 450 Holley to my specs , quick change kit, P/V , cam  etc for around $250 , I could not tell it was a referb its that good. He also made the base for me .



"Came too close to dying to stop living now!"

Iv'e had very good luck with an Edelbrock right out of the box.  One on a modified 312, the other on a 302.  Both 600's.  If you still have an manual choke, a manual choke 500 cfm should work very well.


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

You might think I'm "nuts" , and because I'm old school, you can't beat an Autolite 4100 4 barrel.It's one of the best, simplest and troublefree carbs ever made. Get the larger venturi 4100, if your lucky enough to find a 1958 model that is 669 cfm. If not the big block 4100 is next best, with 1.12 venturi which is 600 cfm. Lastly is the smaller venturi at 1.08 used on 289 V-8 which was 480 cfm. Remember, unless you have a big breather and header exhaust, over carbing hinders performance. If you use a guide for sizing CFM, a 272 doesn't require 600cfm.

1957 Thunderbird 312 Fordomatic