Here are the ‘very summarized’ results of how sixteen different pairs of heads recently performed on the 312 dyno mule.  A pair of the ECZ-C’s and C1TE-D’s was a before and after milling comparison which  jumps the number of published tests to eighteen.  The same carburetor, intake, headers, timing, and valve lash was used in all these tests.  The camshaft is a Crower Monarch with 0.450” lift, 238°@0.050”, ground on 110° lobe centers, and installed 2° advanced or 108° intake lobe centerline.    The intake manifold is an unported Mummert dual plane paired up with a 750cfm vacuum secondary Holley sitting atop a 2” oval opening carb spacer.  1.6:1 roller rockers are being used for all tests.  Total ignition timing is 38° BTDC.  For these particular test results, the headers are used with mufflers which helps to keep this particular information set comparable.  The degree or amount of porting when performed on the heads is not listed on this particular chart.

 

Cylinder Head	Peak HP	Peak Torque	Comp Ratio	Ported
Mummert Aluminum	377	368	9.8:1	Yes
Mummert Aluminum	354	356	9.8:1	No
113	333	350	9.2:1	Yes
G	328	350	9.4:1	Yes
G	324	349	10.6:1	Yes
G	304	337	9.6:1	Yes
G	302	337	9.2:1	Yes
G - stock	290	344	9.2:1	No
471	296	332	8.3:1	Yes
ECZ-C – stock	288	336	9.0:1	No
ECZ-C – stock	280	335	8.6:1	No
ECZ-C – stock	273	330	8.1:1	No
ECZ-C       after milling	295	339	9.0:1	Yes
ECZ-C       before milling	290	334	8.4:1	Yes
C1TE-D    after milling	297	337	9.0:1	Yes
C1TE-D    before milling	295	335	8.4:1	Yes
COAE-A - stock	283	332	8.7:1	No
COAE-A w/larger valves	273	328	8.9:1	No

 

A special thanks goes out to those of you that donated heads, shipping, and/or funds to make all this happen.  For those of you that sent funds without any name(s) on the envelopes, an extra thanks also.  This testing has generated a plethora of information which is being put together for a series of articles for the Y-Block Magazine.

Lorena, Texas (South of Waco)

There is some amazing information in that chart!  A thankyou isnt sufficient, but "Thankyou!" Ted.

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.

Some interesting data. In most cases, an increase in compression or port/valve work increase power except in the case of the larger valve C0AE's and the 10.6:1 G's, which performed well but weren't at the top of the G list. It looks like reasonable street performance can be had with virtually any head.

Are you going to score these using the Engine Masters format?





Lawrenceville, GA

And the ported 113 made more power that the G with less compression.

Glen Henderson



Freedom is not Free

Letohatchee, AL

Great work, thank you very much, and thanks to all who helped out.

 lincoln/merc. y-blocks &mel's                                                               bucyrus, ohio.

Thank you Ted ! Wish I had this info when I built my engine, very happy with the way it runs but for the amount it cost to go to G heads I probably would have just done work to my C's.

1956 Fairlane Victoria (ORREO)

 

Overlooking Beautiful Rimrock AZ

Awesome info, Ted! Thanks for the amazing work putting this together.



It's interesting that the high-compression stock C heads weren't that far off in power from the stock G heads! It's easy for me to lust for the "best" heads, but the G head valves are only slightly larger and the chamber volume is only slightly smaller. These numbers prove that the difference really isn't that great, from a practical point of view.



You may have just saved me some bucks! Thanks again!



Now, if I could only stop lusting for that tri-power...

Thanks for the testing Ted!  You do us all a great service.   But I think I will benefit even more when I can bolt those "G" heads on my engine at Bonneville.  I plan on making two full runs with the C1TE heads that are on the engine now (very similar to the ones tested) then swap for the old "Brick" heads and we can see what that change makes on the course.   I also have a Mummert intake to run, but I have a ported "B" on the engine now and will run that with the "G" heads to get an apples to apples test.  As long as my +.060 292 bottom end will hold up and the truck handles good I should be able to make quite a # of runs to compare set ups.

Next year hopefully some CNC ported Mummert heads, I think that is what I will need for a D/PP reacord.

   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

Great job as always Ted! Great info.

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?

Ted

Once again a great job. Thank you for all your time and effort.

Seeing the results of the cylinder head test and having facts and hard data as opposed to myth, urban ledgends and speculation makes me smile. Since I remember the day when the Yblock G heads were just the ones with the larger intake valves already in them and not the object of almost magical regard this helps to put it into perspective. In the case of the G heads maybe you really do not get what you pay for after all.

So don`t believe everything you hear. Pete