By the time you put into reworking the A manifold I would think it cheaper to just by a B manifold and have better performance in stock condition than what the A can do modified because of the better carb selections for the B. From what I see from Teds experience the B kills the A from airflow and that goes a long way in making power.

-Gary Burnette-

For those of us stuck with an "A" manifold, for the time being,does anyone think that it would be advantageous to convert the four hole design to two ovals as has been suggested for the "B" manifold? If yes would you also slot the carb adapter plate?



Mark

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia

Performance will depend a lot on how it's jetted. But that sounds to me like a lot of carb for a 272 with that manifold. Your setup is not going to approach that 600 cfm of air. Holley makes the 4160 390-cfm, vacuum secondaries carb which would be the first thing I'd look at. Straightforward and affordable. Holley also makes a 450 cfm 4 barrel but I think it's only available with mechanical secondaries, intended more in a multiple carb setup. Demon makes good carbs, they have 525- and 575-cfm versions available with vacuum secondaries, but they're pricey and they may suck down more gas, apples to apples.

Are you going to run a test with a Lincoln or Merc WCFB on the "A" manifold?. I could supply a newly restored carb for the test all I need is it sent back after the test......JD

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Texmark: Re your 600 cfm carb question.. Ted's test mule engine is 50 cu.in. bigger than your stock 272, & had better heads etc. It's very likely that 600cfm is overkill. 57-312s didn't use a carb that big..

Paul

Ted, please, give us fair hp numbers with all tested at 5000 rpm. We all know 5100 rpm  and 6000 rpm are not the same. As at our dyno sessio we got about 10 to 13 hp more with every 100 rpm increase it sure makes difference.

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

Ted, Any chance that test could be duplicated on the B intake?


Frank/Rebop

Bristol, In ( by Elkhart) 

It looks to me like the intake is the limiting component; You'll probably get about the same peak numbers with any 4v carb on the A manifold. Ted, how does the low end compare with the different carbs?


Lawrenceville, GA

So, make it simple for a country boy with an "A" manifold...

Holley 600cfm sounds like a fit for a stock 272 that gets driven mostly locally, every few days..., right?

Mark

"God Bless Texas"location: Houston,TX

Very interesting on the Lincoln teapot being able to hold its own against the other carbs.

I knew the Lincoln teapot was good as we would switch the Ford/Merc Holleys years ago fast if we were fortunate enough to find a wrecked Lincoln to grab the carb.That change sure enlightened the 55/56's with the "A" style manifolds.

I ran a Lincoln teapot on my car until I switched to the FAST fuel injection two years ago.

marv