I figure this question from Daniel deserves a new thread which in turn will help to keep this topic separated from the 3X2 testing thread.

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I recently tested the new Mummert manifold against the stock ECZ-B intake on the dyno mule prior to the 3X2 testing but the testing was performed with Reds (or Hedmans?) headers going into 4’ long 2” diameter lead pipes with no mufflers.  That exhaust system was later found to be too restrictive and in the ECZ-B vs Mummert test, a dip in the torque curve became obvious with the Mummert intake.  When the Mummert intake was later reinstalled on the engine with the better exhaust system, that dip in the torque curve cleaned up nicely.  At this point the stock intake hasn’t been rerun with the improved exhaust system yet so there isn’t a good direct comparison of the two manifolds with the improved exhaust system.

 

But I do have a comparison of both manifolds with the ‘poor’ exhaust system.  Both 4V manifold tests did use a L1850 600 cfm Holley that has had the air horn milled off and a K&N shorty stub stack on its top and the engine was using a set of replacement 1.40:1 rockers at the time.  Using the same scoring format as used in the 3X2 intake testing, the results with the ‘poor’ exhaust system are as follows:

1590.4 pts – Mummert aluminum intake with a HVH 1” ‘Performer’ dual slotted spacer

1572.7 pts – Stock ECZ-B iron intake with a Wilson 1” four hole spacer

 

Translated to peak torque and HP numbers, the results look like this:

314.4 Tq / 260.9 HP – Mummert aluminum 4V intake

313.9 Tq / 249.9 HP – Stock ECZ-B 4V intake

 

In looking at the raw data, the stock manifold is a better performer up to 3700 rpms at which point the Mummert intake takes over.  Overall score does fall to the Mummert manifold though if you have your foot into the throttle heavily.  If you’re simply just driving around, then the tip of the hat goes to the stock ECZ-B intake when using a restrictive exhaust system.

 

It was after that particular round of 4V intake testing that the four tube headers with mufflers from the EMC project were tried while sorting out the Stromberg carbs on the Edelbrock 573 and a clean 22 HP was found just in changing out the exhaust from one to the other.  After that one change the engine started responding nicely to the other changes including the rocker arm ratios.  With the Reds/Hedmans headers, the engine seemed to be stalemated at the 250 HP mark even with many of the changes that were being made and using the ECZ-B intake.  The Mummert intake was worth another eleven horsepower over the stock intake but it was eventually found that the exhaust system was holding back the potential for more.  That same engine is now sitting at 292 HP with the Mummert manifold with the improved exhaust system and 1.6:1 rocker arms.  The stock unported G heads are still on the engine at this point and there are plans to retest the stock intake on the stock heads with the better exhaust system at this point after looking at the data.

 

Obviously the very next round of testing will be going back and testing the stock ECZ-B 4V intake, the Blue Thunder intake, and the Mummert intake with the current exhaust system.

 

Lorena, Texas (South of Waco)

Hi Ted, could you clarify the diameter differences in the two different exhaust systems in your tests? Do you think it's the exhausts, or the rocker arms (1.4: 1 vs. 1.6:1) having the greater impact on the differences in output?

Good stuff!   Looking forward to the results.

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias

Ditto.


Lawrenceville, GA

Again Ted, WOW!

This is great information for all of us, and will prove worth its weight in gold in the long run, and for many years to come in my estimation...where is HOT ROD magazine when you need them? Wish we could set that record of the Y block's ability for excellent TORQUE and HORSEPOWER numbers at the same time. To me, the Y block tends to be an engine that delivers an awesome torque:horsepower ratio at many levels of engine rpm. From what I have read and seen, our engine responds well to subtle changes and the direct proportion of the numbers tend to remain solid over a good range of rpm.

Many people still do not believe the torque and horses coming out of a mild 292, .060 over, that installed in my old Club Sedan a couple years back. With stock G heads and the 1.54 rockers and stock exhaust (ok, she does have glasspacks) and a B intake, much juice was still being delivered to the rear wheels through the "horspower robbing" Fordomatic. Albeit a standard transmission would deliver better numbers to the rear wheels because of the rpms and such, I think old Henry knew what he was doing with the engine and transmission combinations with the known info at the time of manufacture.

Real world testing like yours lets us know solid figures and performance numbers on the same engine (a constant configuration). Believe me, being a school administrator I know a little bit about science projects, hypotheses, theories, abstracts, control groups, experiments, and the like. You are right on the money with this project.

Sounds like a good science project for my son one of these days! Can't you just see us backing up to the gymansium/science display center unloading an engine test stand with a Y block on it trying to answer the hypothesis that questions which intake flows more volume, etc??? Awesome!

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

Daniel:

Good observations, except one minor point.  Ol' Henry didn't have anything to do with the Y, he died in 1947.  But the groundwork he laid in the '40s paid dividends in the '50s.

John - "The Hoosier Hurricane"

Ted, excellent information that really underscores the importance of the exhaust system. I think that the 292HP mark for the stock heads is close to the max from the other testing I've seen.

When we did back to back testing of ECZ-B and Blue Thunder a number of years ago we found 2900 RPM to be the break even point. The engine was a 332 cu in street engine with a good set of headers and well ported ECZ-G heads.

On another engine the original flat exhaust manifolds were nearly as good as an old set of Hedman T-Bird Tri-Y's. The Y-Block just doesn't like 1-1/2" headers from the testing I've done.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

Yes, Hoosier - a slip of the tongue, er keyboard, I mean. Forgot that old Henry wasn't still alive when the Y block made its debut. But like you say, he did lay the groundwork. I love our Y better than any engine, but we all know how much of a difference the Flathead V8 made in America, much less the world.

One of Henry's best ideas (well, not too related to cars, but it was related to machinery) is Greenfield Village up in Detroit, MI. I took my kids there 2 summers ago - my kids are 6, 8, and 11 - You would have thought they were at Disney World! They just loved it. I had a hard time pulling them away. His foresight to preserve some of America's most treasured history was truly ahead of its time. By the way, my family just loved riding around in Model T's all day to see the sights...a real credit to Ford engineering and longevity.

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

Definitely the exhaust system.  The exhaust system that was being used originally on the dyno mule was a set of Reds/Hedmans headers connected to a set of lead pipes 2” diameter about four foot long.  No mufflers.  The engine was unresponsive to timing and jetting changes with that system but was overly sensitive to air changes that were taking place over the course of a days worth of testing.  It wasn’t until the four tube headers and mufflers from the EMC project was installed on this engine without any other changes that it became clear that the other exhaust system was holding the engine back.  The Y engines in general appear to be much more sensitive to exhaust system design than many of the other engines I’ve tested.

 

As a side note, the 1.4, 1.54, and 1.6 rocker arm assemblies were tested after changing out the exhaust systems and each upgrade was worth ~3 horsepower.  That’s a six horsepower increase going from the 1.4’s to the 1.6’s.  That particular test took place while the Edelbrock '573' 3X2 setup was on the engine so figure about a 1% change or increase in horsepower output for each incremental step up in rocker arm ratios. 

Lorena, Texas (South of Waco)

Ted/John,

In the exhaust issue department, What are the best diameters for headers and exhaust systems for a healthy street car?

should primary's be 1 5/8", 1 3/4" and what size collector? should the rest of the system be 2" 2.5" or larger?

I wanted to start making my own set of headers is why I am asking this.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?