My 55 TBird has an iron ECZ-B Intake and a Holley 465 4V.  According to Ted's website test, his mule Y-Block engine made 240 HP with the same intake and a Holley 750.  His engine with a Mummert Intake and the same carb made 276 HP or an increase of 36 HP.  That seems like a lot of HP for an intake swap.  Mummert makes a low rise manifold to fit my TBird.  Should I consider making this swap?

Which article is it?



Lawrenceville, GA

The ECZ-B intake manifold is internally sized for using stock flowing G/113 heads and a stock camshaft.  As soon as the heads, camshaft, and cubic inches are upgraded, so too is the need to increase the flow characteristics of the intake manifold in order to capitalize on those other changes.  While porting the stock ECZ-B intake manifolds can bring those flow numbers up to equal those of the stock Blue Thunder or Mummert 4V aluminum intakes, additional porting of the aluminum intakes takes those power levels up another notch assuming the cylinder head flows are increased accordingly.
 
Here is an excerpt from an upcoming article for The Y-Block Magazine.
 

Lorena, Texas (South of Waco)

My engine is a near stock 292 +.060".  My heads are 1957 "G" heads and rockers from a 1957 passenger car. I also have an Isky 301333 cam. My 465 Holley with a 1/2 spacer runs good and is very responsive off idle to 5,000 rpm.  My car has a stock three speed transmission with O/D.  Given these factors, I would guess my engine is producing about 230-240 hp?  I would like a little more grunt.  I never turn my engine over 5,000 rpm.  If a Mummert intake and carb upgrade would give me an additional 30 HP, I think it would be worth the cost.  I've tried a few multi carb setups on my car with mixed results. 

Phil, it would be interesting to see the numbers from 1800 to 3500 rpm. If you could get 15-20 hp gain in that range I believe you could really feel it in your seat....but when you do who’s going to stop at 3500

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

1800-3500 range is where most of us run on the street. Gaining HP above 5000 is not beneficial if you lose HP and torque in the normal operating range. If I recall, Ted's tests begin at 2500 rpm. 

The question is, "Do these mods make a difference in performance you can actually feel on the street?"   Thirty HP on a 250 HP motor is a bunch.  Has anyone swapped out an iron intake manifold for a Mummert or Blue Thunder?  Was the increase in power noticeable on the street?  What carb did you use?

The average flow through that B intake manifold is ~182-185 cfm, the Mummert out of the box flows 274 cfm average.  The BT out of the box is 279 cfm average.  Joe-JDC

JDC

According to Isky, your cam range is 2500-5500 rpm. However, the stock "G" intake port flows 175 cfm/"Street Port" 215 cfm @ .500 lift. The Mummert/Blue Thunder manifold would be a good match with your cam and ported G heads at higher rpm. This might help: ford-y-block.com/porting.htm. 

Ted recommends opening up the "B" manifold plenum to 2 ovals. That should give you a few more cfm, but really no point if it outflows your heads in stock form. I would email Ted, who has had far more experience than I with such matters. He probably knows what will work best with your cam. I would think that a larger carburetor would better compliment your cam, possibly 600 cfm. What are you using for exhaust?