I see you noticed my post.  A member on the FE Forum mentions about his "little chamber 2x4 non supercharged heads".  I believe these just to be common ECZ-G cyl heads, and not some "mystery" component.

To clarify the EDB-6090-C cyl head specifications.  It was released 12-14-56 on Release # E7-995.  Same as ECZ-6090-G, except use ECR-6090-D lower water jacket core.  (ECR is 272 HD truck)  Volume of combustion chamber to be 74.16 - 77.16 CC with valves & spark plugs in place.
If I recall that same release number shows up on other Phase 1 S/C related components, i.e. - camshaft, brackets, etc ... .

Re 312 285 hp engine.  Internal Ford technical documentation on this engine is virtually non-existent, even though it was advertised.  Believed to be a kitted engine, it was "available" from the introduction of the 1957 models until the release of the supercharged engine late Dec 1956.  The 270 hp engine would continue to be available. 

Regards,
Dennis

Regarding the three different SC heads, I've picked-up the same info from John Mummert's web page with what he's gleaned of cylinder head castings, Royce.  The EDB-Ds and EDB-Es were production numbers while there is indication that the EDB-Cs were hand stamped and may have been (?) early (?) factory race application units.  The 'early' designation is tied to lettering designation usually being assigned to letters ascending in order.

See JM's info at  http://www.ford-y-block.com/cylinderheadchart.htm

In reading James Eickman's 1984 Ford Y-Block book, the info on page 27 states that the first (production) EDB-D heads had no 'posting' "which sometimes failed in competition usage", then goes on to describe Vern Schumann's modification of these heads by screwing a bolt through the water jacket to support the backside of the combustion chamber wall, and then indicates that Ford subsequently "accomplished the same with a head casting EDB-E that incorporated an internal steel support rod".
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Regarding the suggestion on the FE Forum that 'E' code 285 HP ECZ-G heads may have been factory broached .060 to reduce the combustion chamber volume and raise the compression ratio...  anything is possible, BUT the decks on the 'G' heads were thin at their normal production thickness whether produced during the '57 or (for the Mercury) the '58 model year.

The above said, my recollection is that the over-the-Ford parts-counter, late '56 power pack set-up 2x4 set-up included 'C' heads that had been broached .060 to increase their compression ratio... 

Returning to the ECZ-G head information suggested on the FE Forum by a participant, in reconditioning work, both John Mummert and Ted Eaton have not recommended milling 'G' head surfaces more than .025 maximum for reliability reasons.  I can't remember reading anything from Tim McMaster on this...      


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

I lifted this from a Y Block discussion on the FE forum.  Was I not paying attention in Y Block class?  3 S/C heads?                                                                                                                                                                                                                                                                                                                                                    

Yes, that is correct. The way Bill posted there and had previously posted about his motor, it may elude the 1957 312-270 hp 8V cyl head was a unique component, not the common ECZ-G head used across the board on 272-312 non supercharged applications. I was trying to find out if Bill had any info on a unique 270 hp cyl head.

The 57 312 8V 285 hp head may of been the ECZ-G, milled .060", along with dual valve springs and no oil seals.

Per ECZ-6090-G b/p, Volume of combustion chamber to be 66.35 - 69.35 cc with valves and spark plug in place.

In addition, there were at least three S/C cyl heads. EDB-C released for the Phase 1 application, EDB-D, and EDB-E.

Regards,
 Dennis]