Update: I took the C heads to the machinist early this week. C heads didn't pass the mag test, G heads did. No wonder I got C's for free.

  Dennis in Lititz PA

I took the G heads to the machinist today.[1st one I worked on to get the valves out]. I took another look at his Wallys. One was for 1975 Newark OH, the other 3 were for 1977, Englishtown,Gainesville, and Pomona.They said class winner but they didn't say what class. I think he had a 60 corvette.

  Dennis in Lititz PA

Dennis.  I looked through my collection of heads and didn’t find an EBU head in which to cc a combustion chamber on.  Best estimates based on the piston being 0.043” in the hole and 7.00:1 compression ratio puts the chamber volume at 70cc.  If going for the full rated 7.2:1 CR, then the combustion chamber would be 67cc.  This is using a 0.021” steel shim gasket that figures out at a 4½cc volume.

Lorena, Texas (South of Waco)

Dennis:

You probably want to discuss air flow with him.  The G heads may have too big ports and valves to be streetable with 256 inches.  Of course, you can always put more cubic inches under the G heads.  It just never ends when the bug bites, does it?  But I just now remembered that Ford put G heads on 272s.

John in Selma, IN

John - "The Hoosier Hurricane"

I went to my machinist today and showed him this topic printout.Now he wants me to bring both C and G heads. Wants to cc both of them and the runners.



I also saw 4 Wally's on a shelf. I'll have to look next time to see what years and class they were for. I was told he used to race in his younger days.

  Dennis in Lititz PA

Frank:

I think Ford claimed they made the C heads 10:1 on a 312 when they milled them .060 for the 260 horse "race kit".  Dennis would not get as much gain on his 256 though.  Dennis, looks like the C heads would make a good choice for you, plus, you already have them.  Have at it, and good luck.

John

John - "The Hoosier Hurricane"

John,

     How much does he gain cutting his C heads .060? I thought those were fairly good flowing heads.

Frank/Rebop

Bristol, In ( by Elkhart) 

John, I was concerned with water leaks with bigger heads. I have a 54 3x2 on now. [no air or water leaks] I also have a big port 3x2 and a 4 barrel B intake.Also C and G heads.

  Dennis in Lititz PA

Dennis:

I made some rough calculations that have some variables in them, so the results are only indications of what will happen when you use different heads.  I didn't calculate the CCs of the 239 heads, since I don't have any figures for other heads either.

When you took your 239 out to 256, you took the compression ratio to 7.7.  With '55 2 barrel heads, you would have 7.1.  With '55 4 barrel heads, 8.1.  With '56 ECZ-C heads, 7.36.  With '60-'62 passenger heads, 7.7, but you are back to the '54 size valves.  Remember, these are all BALLPARK numbers, not actual measurements.  I don't remember, is your intake a '54 or a later one?  Is this the leak you are trying to fix?  Also, there may be some water passage issues when putting later heads on a '54.  Ford used to make a special head gasket for this swap.  I assume that making sure there are holes in the gasket where needed would be all that is needed.  I once put late steel shim gaskets on a 239 and water leaked into the cylinders.  Composition gaskets solved that problem.  If you have the '54 intake, a change to a later one would make good sense if you change heads.  Also, as a rule of thumb, Y heads can be milled .060 with relative safety.  The intake surface of the head needs to be milled about 1.4 times the amount taken off the head surface.  Hope this helps.

John in Selma, IN

John - "The Hoosier Hurricane"

Ted, I pulled the rocker covers. Here's the numbers inside EBU 6090 A1 date code 42S. It uses a small plug like a lawnmower with a washer. Thanks if you can help.



There was also a fomoco script inside an oval. Very fine detail,I was surprised they went to that much trouble.

  Dennis in Lititz PA