9.09:1 static compression ratio for a 292 with 0.020” overbore and pistons in the hole 0.025” with the Mummert aluminum heads (60cc).  G heads at 69cc’s on the same engine will have a cr of 8.22:1 while the 113 heads at 72cc’s will lower the cr even more to 7.97:1.

9.65:1 static compression ratio for a 312 with 0.020” overbore and pistons in the hole 0.025” with the Mummert aluminum heads (60cc).  G heads at 69cc’s on the same engine will have a cr of 8.72:1 while the 113 heads at 72cc’s will lower the cr even more to 8.45:1.

Lorena, Texas (South of Waco)

Ted or perhaps John M, i cant recall any mention on the new aluminum heads if they are posted in some way  or cast with reinforcment to prevent problems encountered with CI heads, and what torque tension would apply to these heads using ARP screw in head studs. thank you, regards bill.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

For the first round of testing on the aluminum heads, ARP 7/16” bolts were used.  The long bolts (top row) were torqued to 75 lb/ft while the short bolts were torqued to 70 lb/ft.  Upon removing the aluminum heads from the engine after 78+ dyno pulls, the head gaskets showed zero issues.  No distress at all.

Lorena, Texas (South of Waco)

The new heads are .600"+ and since there is more material around the ports the deck surface of the head spans a shorter distance.

http://ford-y-block.com 

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

John, thanks for that, i thought along those lines but was curious, good job.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia