What is the diff. between A code and K code Mustang 4100s?

What is the diff. between A code and K code Mustang 4100s?

Mike
Mike

December 31st, 2009, 12:44 am #1

Both the A and K code 289s had 4100s, but the A was 225 hp and the K somthing like 271 hp. Were the carburetors setup differently, and if so how? Or maybe the increased hp was gained via cam and compression. I think the A carb was 6ZA, dont know about the K.
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Lee
Lee

December 31st, 2009, 3:03 am #2

as far as boosters and jets go...not to mention manual or standard tranny, vent tube or PCV, auto or manual choke. Then there is the BIG difference...value! The "factory original" HiPo carb is worth alot more than the standard 4-V one.
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Lee
Lee

December 31st, 2009, 3:46 am #3

the venturi sizes are different as well...the HiPo one being the 1.12 vs the standard one at 1.08 inches. I looked at my book and the jets are WAY bigger on the HiPo, especially the secondaries, but some of the boosters are the same between the two different sized carbs.
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WerbyFord
WerbyFord

January 1st, 2010, 4:26 pm #4

Both the A and K code 289s had 4100s, but the A was 225 hp and the K somthing like 271 hp. Were the carburetors setup differently, and if so how? Or maybe the increased hp was gained via cam and compression. I think the A carb was 6ZA, dont know about the K.
Those are the parts that added power to the 289 k-code. The other stuff just added revs to match.
Carb was bigger, 1.12 vs 1.08 as stated (the throttle bores are bigger too).
Cam was bigger, 289/"271" had about 228-228 solid duration at .050" lobe, and the 289/"225" had about 180-180 at .050", a teeny tiny cam, great for watching the fan blades at idle but not much else.
Compression was higher, over 11-1 on the early 289/271 vs 10-1 on the 289/"225".
Exhaust manifolds are also way better than those twisted drinking straws used on the other 289s.

Intake and head flows were about the same which is why the 289-K *only* made 271hp. A good intake (and heads) will really wake it up.
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