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MG MGB GT V8 Factory Originals Technical - model # for Carter 400 carbs?

Does anyone know the model number for the unfortunately no-longer-available Carter AFB 400 carb w/electric choke? I believe Carters usually have a four digit number with a hyphen with one or two letters after it, like "1234-AB"
Harry

Harry,
I have an old Kenne-Bell catalogue at home the has the number, I'll look it up tonight. I have an unused 500 CFM AFB with elecric choke for my 3.8l V6 Buick. I think the number is in the 9400 series.
George B.

George, thanks ... the Edelbrock seems like one heck of a lot of carb to run on your 3.8L. Wasn't the old muscle-car mantra "100cfm per quart"? Won't your low-end really suffer? Are you going to put a restrictor plate in there?* I had an Edel. 500 on my Rover 4.2 and it was way too big -- sloppy and smelled like rotten eggs at the low end. Going for a Holley 390 or maybe a Carter 400 if I can find a decent one. I realize the top end won't be as glorious, but I don't often run the thing at 7K rpm!




*-incidentally, what's wrong with restrictor plates? People seem to despise them and it's not exactly clear to me why that is.
Harry

Harry,
A two inch air cleaner will probably restrict the air-flow anyway. The primaries are fairly small, so if I stay out of the secondaries untill I have good RPM I think it'll be OK. People that despise restrictor plates are used to them being used to reduce the power output of racing engines for safer racing and a more level playing field. They must not believe in those aims.
George B.

Harry,
I guess I wasn't having a "senior moment". The 400 CFM Carter AFB number is 9410. My 500 CFM Carter AFB with electric choke number is 9510. The 10 in both numbers is probably the modifier for the choke. These carburetors were used on some 60's and 70's Mopars, but I don't know which models.
HTH, George B.
George B.


If you're calling a piece a sheetmetal with holes in it a "restrictor plate," it shouldn't
be hard to see why they don't belong in the intake tract of ANY automobile. In simple
practical terms, they don't just reduce the volume of air - they horribly disturb the
flow of air. Your pistons can suck a lot of air through a restriction, but the restriction
will cause radical local changes in pressure and will also cause poorly controlled
turbulance. Presumably, you'd propose to put this restriction immediately AFTER
the carburetor, which means you'll have fuel vapor marginally mixed into the air.
Without sophisticated test equipment and development time, you won't be able to
"optimize" (ie: reduce the effect...) how the pressure and turbulance affect the fuel
mixture. In other words, your "restrictor plate" will screw up how air is vaporized in
the barrels of your carburetor.

I'm no expert in fluid dynamics. I used to race in a class that mandated an intake
tract restriction - but my colleagues were allowed to develop and build a LONG
"converging/diverging nozzle". This nozzle allowed us to have a very stream-lined
flow of air throughout the intake tract. Other methods of slowing classes of race cars
are far more elegant. Personally, I prefer having tighter turns at closer intervals -
on the race track! And for professional racing, where the engines are far from stock
anyway, it obviously makes more sense to limit displacement, limit turbo boost,
limit fuel alternatives, limit...

Incidentally, the popularity of our favorite engine (the Buick 215/Rover 3500) owes
much of it's popularity to EXACTLY that line of thinking. Because of a reduction in
allowed engine displacement, in 1967 Gran Prix teams had to quickly develop newer
SMALLER engines. Brabham turned to the old, discontinued Buick 215 as the basis
for his development, whereas Ferrari and the the other teams had to start from
scratch. This decision led to two Gran Prix championships. Though there were
undoubtedly other factors, without this success the engine may have never won its
way into Rover automobiles.
Curtis

The "10" in Carter carb model numbers indicates a Chevy, or GM style of throttle linkage.

Many of us run the 500 cfm Carter very successfully. The Carter is much more forgiving "out of the box" than the Holley. You should have no problems with a little re-jetting, running the carb on 215/3.5L V8's or the 3.8 V6. I have run both a 400 & 500 cfm on 215 Buicks with little difference in performance.

Agree on the home made restricter plates. Drilling 4 holes in a piece of aluminum will not maka a 400cfm out of a 500cfm card, just a poor performing 500.
Jim Stuart

Harry, I fully agree with Jim Stuart. I also run a Carter 500cfm with electric choke on my 3.5 L Rover. I think it runs very powerfull throughout the whole rpm range and the higher RPM's the more power. Don't see the need to change to a 400 cfm. Ask Glen Towery, he knows .
Werner
Werner Van Clapdurp

This thread was discussed between 15/08/2000 and 30/08/2000

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