Have now completed running an assortment of headers and exhaust systems on the 312 dyno mule.  The mule engine is the same +060 over 312 that’s been used in a variety of other tests.  Specifics for this engine are cast pistons being 0.025” in the hole, ECZ rods, a Crower Monarch camshaft with 238° dur @ 0.050” and 0.459” lift at the valve after lash, an unmodified Mummert intake, and 750cfm Holley on top of a 2” carb spacer.  A set of mildly ported G heads that have been heavily milled brings the compression ratio to 9.6:1 .  Originally being unposted G heads, a pair of posts were installed into each head prior to using them for this series of tests.  With the mill and the porting, these heads were roughly worth 18HP over a set of stock G heads that had a measured static compression ratio of 9.2:1.  With the mild port job, consider these heads a Stage I port job.  There’s over 300 dyno pulls now on the mule engine and the bottom end is still holding up fine other than the rear main has started leaking.  Although the oil from the rear seal is not pouring out, it’s enough to remind you that this engine is now marking its territory.

 

Mufflers were tested on most of the exhaust combinations and only with the EMC headers did the HP & TQ numbers actually improve with the addition of mufflers.  All other systems did not particularly like the mufflers.  Different inlet sized chambered mufflers were used and which ones being used was determined by the exhaust sizing going into them.  The test range for this series of tests was 2300 to 5500 rpms.  The test range was lowered down to 2300 rpms for the exhaust system testing to get the engine rpms down to that critical lower rpm range that would be seen on a daily driver.  Many of the exhaust systems were tested with varying extension pipe lengths and with & without mufflers.

 

For simplicity while also providing a quick overview of how each system performed, here’s the charted summary based on the best score for each system that was tested.  Scoring is calculated by adding the average torque and horsepower for the test range, multiplying by 1000 and dividing by the cubic inch.  I’ll add that the best score didn’t necessarily give the best peak HP or TQ values but scoring does gives a better indication of how the ‘as tested’ exhaust system will work in regards to overall performance.  On this chart, the peak HP and peak TQ values are those that belong with the score while the ‘Testing configs” column tells how many variants of that particular exhaust system were actually tested.

 

Description.	Score	Peak HP	Peak TQ	Avg HP	Avg TQ	Mufflers	Testing configs
Single exhaust with crossover pipe	1484	239	303	202	276	NO	2
1955/56 Dual Exhaust manifolds	1629	274	327	223	301	NO	4
Reds two tube headers	1635	278	327	224	302	NO	3
1957 Dual Exhaust manifolds	1650	279	330	226	305	NO	4
Fenton cast iron manifolds	1663	282	332	228	308	NO	2
Tri-Y stepped shorty Tbird headers non-firing order specific - GB	1675	294	332	230	309	NO	4
Ram Horns w/2” into 2¼” pipes	1683	283	337	230	312	NO	2
Shorty 1.625” w/box collectors - DC	1693	284	336	231	314	NO	1
Sanderson 1½” T-Bird header w/2” pipes	1724	290	346	236	319	NO	4
Sanderson 1½” T-Bird header w/2¼” pipes	1726	289	346	236	320	NO	4
JC 4 tube car chassis shorty headers	1739	296	347	238	322	NO	6
Tri-Y pickup headers firing order specific-CC	1739	297	347	238	322	NO	5
Sanderson 1½” T-Bird header w/2½” pipes	1751	297	350	240	324	NO	3
Sanderson 1½” Pickup headers w/2½” pipes	1751	300	350	240	324	NO	5
Fenderwell headers 1.75” tubes - MW	1768	306	344	242	327	NO	5
Fenderwell headers 1.625” tubes	1769	308	346	243	327	NO	5
KC 4 tube Maxton Mile 1 5/8” headers	1775	310	351	244	328	NO	4
EMC headers 1.75”/1.875” stepped	1780	310	349	244	329	YES	4

 

Unfortunately the individual numbers don’t tell the whole story.  The torque curves could be manipulated with different lengths of exhaust pipes or the point in which the muffers were inserted into the system.  I’ll work on some graphs down the road which will better illustrate this.

 

A big Thank You to all of you that contributed parts or pieces for this exhaust test.  For those of you that sent manifolds or headers for testing, email me and let’s work on getting those pieces back to you.  My email address is under contact info at the following site:  www.eatonbalancing.com

Lorena, Texas (South of Waco)

Very interesting Ted. Thank you so much for all your hard work.

1956 Fairlane Victoria (ORREO)

 

Overlooking Beautiful Rimrock AZ

The greatest improvement comes by simply fitting dual exhaust. That switch alone accounts for nearly half of the total power improvement in the table.

1 1/2" headers are not nearly as bad as I had thought but it does look like 1 5/8" might be generally the best for street performance.

Excellent work, Ted!



At 10.6:1, is it still on pump gas?


Lawrenceville, GA

It's good to see 50 years later that 1958 dual manifolds were an improvement on my 56 Ford over the stock single. Not just in my head. And besides that it sounded a heluva lot better. And I kinda think the girls were impressed by the 2 chrome tips hanging under the bumper

Kenneth

Fredricksburg, Texas

Ted - we owe a lot to you on having all this information at our fingertips. Talk about dispelling myths, etc.

How many of you guys vote for Ted being the next author of a "Y block book"? Obviously, one geared towards performance. In my opinion its about time for another one to hit the mainstream, dispell the myths, tell the real story, and give all of the performance features of the mightY engine we love.

Daniel Jessup

Lancaster, California

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

"The 21st Century Y-block"  by Ted Eaton.  Sounds Good!

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

Ted,

Is one of these the headers I sent home with you last year? I think they were pickup style. You had once said you thought they would flow very well. Also how is my project going? Chuck in NH

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Ted,

I would like to concur with the rest of the guys that we are so lucky that we have you doing all the testing for us and I can tell you it has been very beneficial to me and many of us Y-Blockers.  I saw a post a while back that Alan Frakes had made indicating that he might be sending you  a set of the Bird headers that J. Mummert handles.  David Church has a set he will run on his E-Bird that he is restoring and I have a set that will be on my Bird if we can ever get through with the restoration.

Thanks to You Again for all your work.

Larry Boyer

57 Black Bird

Larry, I was never able to send the FPT tbird headers as I was busy driving the car!



Ted, thanks for all your hard work this is great reference and like Charlie said what a interesting thing to see what happens when you lose the crossover pipe and step up to duals!

       A  L  A  N   F  R  A  K  E  S   ~  Tulsa, OK    

I would like to thank you for another great job of finding and presenting the facts of the Ford Yblock. Mr. Eaton you have done another outstanding job and I am impressed and grateful for all of your hard work. Pete