Mummert Intake Question
Print Topic | Close Window

By Florida_Phil - Last Month
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?
By charliemccraney - Last Month
Which article is it?
By Ted - Last Month
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.
A dyno test where nine different modified single four barrel intakes were run on a 352” Y saw the peak horsepower values range between a low of 455 and a high of 502.  The intake manifolds in that test included modified Ford iron ECZ-B iron units as well as Blue Thunder and Mummert aluminum intakes.  I’ll add that carburetor spacers are also a key factor when dealing with the various intake manifolds.

By Florida_Phil - Last Month
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. 
By DryLakesRacer - Last Month
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 3500Smile
By 55blacktie - Last Month
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. 
By Florida_Phil - Last Month
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?
By Joe-JDC - Last Month
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
By 55blacktie - Last Month
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: 
By 55blacktie - Last Month
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?
By Florida_Phil - Last Month
55blacktie (10/14/2020)
I would think that a larger carburetor would better compliment your cam, possibly 600 cfm. What are you using for exhaust?
I have 1957 Thunderbird cast iron exhaust manifolds on my car with stock pipes exiting rear through the bumper. I feel like I could use a bigger vacumn secondary carb.  I started out trying to keep my car looking stock. At this point, I've changed so many things that it doesn't matter.  I would like to stay with one 4V.  No more old carbs for me.  

By 55blacktie - Last Month
Isky recommends 600-650 cfm with your cam.
By 55blacktie - Last Month
Joe, where did you get the flow numbers for the "B" intake? At what lift?

By Florida_Phil - Last Month
I'm think about buying an aluminum intake and running a bigger carb to see what that buys me. I have a Holley 4V off a '66 "S" code 390 motor under my bench.   I would like to use it so I don't have to go to a dual feed passenger side gas line.   I hate to use tube headers due to exhaust leaks, but it may have to. 
By 55blacktie - Last Month
I bought Sanderson's ceramic-coated headers for my 55 Tbird. The only issue should be having to remove the engine oil dipstick tube during installation, then replacing the tube once the headers are in place. I had considered buying the repop 57 manifolds, but they cost as much as the headers and aren't ceramic coated. The Sanderson headers did well in Ted's test; that why I bought them. I also bought Borla's 2 1/4" Pro XS mufflers and resonators, and will run 2 1/4" pipes through the bumper guards. 

Holley has a 600 cfm single-feed, vacuum-advance carburetor. 

The question still remains, whether the Mummert/Blue Thunder intake will hurt low-rpm torque and HP.
By Joe-JDC - Last Month
I have been porting heads and intake manifolds since 1972, and I have my own porting booth at home, along with a SF-600 flow bench that I have owned since 1994.  I have made special fixtures to flow intake manifolds on my flow bench, and I always flow a manifold before starting any porting work.  I use that information so that I can balance the runner's flow as close as possible between all ports.  Joe-JDC
By miker - Last Month
Phil, I've had no problems with either the Reds headers on iron heads or the FPA headers on aluminum heads on my bird. Higher quality flanges than headers I've used on other engines is what I attribute that to.
By 55blacktie - Last Month
Joe, too bad we aren't neighbors. You're not in California, are you? In your opinion, how much work goes into a "street port" for G heads, besides installing 1.94/1.60 valves? Have you gotten numbers similar to those posted on

By 55blacktie - Last Month
Joe, what increase in cfm would you see by opening up the "B" intake plenum to 2 oval ports and gasket-matching? This is a more appropriate question for Phil's original post.
Phil, that 600cfm (I believe that's what they were) carb you mentioned from an "S" code 66 390 is what I use on my 57 Fairlane 312. The motor was true to 57 including the cam except was .030 overbore. That carb was a very good match for that motor. Not over carburated  at all. Wish I could find another one of those carbs, unmolested, of course. Good luck, JEFF...............
By 2721955meteor - Last Month
have a 600cfm holley4v  on a292.040 over bore,56merc reground cam,works great,lots of power,dual exhaust,with heat riser on drivers side,works great on cold starts, purchased the carb from holleys used website(warranty carbs repaired and resold) at very good price. have used this setup for 4years. myn is in a 1949 mercury  f47
By slumlord444 - Last Month
My experience with the Blue Thunder intake has been great. I replaced my port matched E intake and carbs with the Blue Thunder and a 750 Holley. Engine has Mummert heads and a custom grind Isky cam with Sharp roller rockers. Night and day difference. Better torque in the 5000 rpm range.
By PF Arcand - Last Month
Phil: Black Tie brings up a point.. will an aluminum intake on your engine hurt low end power?.. In the recent cylinder head tests printed in Y-Blk magazine, c/w a Mummert aluminum intake, the "score" for the engine with stock. "G" heads, up to 3500 rpm, was identical to the engine with aluminum heads!  If you're not planning to run over 5000 it worthwhile ??     
By Florida_Phil - Last Month
I'm going on vacation next week.  When I return, I am going to rebuild my "S" code Holley and put it on my iron manifold.  I'll post my results.  Next, I think I'll work on the exhaust. I hate to scrap the 57 Thunderbird manifolds, but the stock pipes are pretty restrictive. My exhaust system is from NPD.  The tubes are small and made up of numerous pieces held together with clamps. It's noisy too and not in a good way.  As 55 TBirds go, my car performs well.  It could be better,
By 55blacktie - Last Month
The stock down pipe, between manifold and muffler, is 2". from the muffler to the exit, the pipe narrows to 1.75." You could keep your manifolds and go with 2" mufflers and pipes, or go with 2 1/4" from down pipe to exit, while still retaining manifolds. If desired, you could later install headers, with only the down pipe between header and muffler needing to be replaced. 
There used to be an outfit that flow-ported and coated iron manifolds to make them more efficient.  Probably much more expensive than headers, but I always wondered what happened to that company, and if anyone has had dealings with them lately (?).  Sure would be simpler, especially for those wanting to retain a more original appearance.
BTW: My Bird had 2” exhaust installed when I obtained it, but everything was rusted out. Buying aluminized OEM replacement parts (except for the glasspacks) was just more expedient on a car with an unmodified engine, and the open exhaust likely more than made up for the smaller pipe sizes.
By Florida_Phil - Last Week
I tried the 600 cfm 390 GT Holley carburetor on my TBird.  Ran into a small amount of clearance trouble with the coil and I had to make a new fuel line. Other than that, no issues.  To be honest, I think it runs better with the Holley 465 cfm.  The bigger carb seems a little stronger in the upper RPM  range, It drives better with the 465 around town.   It's hard to beat the torque and drivability of the 465 on the street.  I guess that's why Ford used it on the 57 312s?