These graphs are specifically for Geoff but others can feel free to comment.  These show the results of some dyno testing with the aluminum heads where both the rocker arm ratios and the intake manifold was being experimented with.  All this took place on the EMC engine combination using last years 824cfm carburetor.  This years carb of choice is making more power but was not included in this round of testing due to waiting for another pair of metering blocks to show up for it.

Looking at the scores for each combination that was tested, the 1.6/1.6 rocker assemblies with the modified plenum intake is 19 points better than the next best combination that was tested.  Each manifold was tested with both rocker arm combinations so there was a total of four different combinations in which to evaluate.  The scoring was only figured based on the 2500-6500 rpm range and does not take into account any activity that’s taking place above 6500 rpms.

Lorena, Texas (South of Waco)

Lorena, Texas (South of Waco)

Finally got in some more metering blocks for the carb I plan on using on the EMC engine and the changes in the metering blocks netted some nice gains both in peak numbers and averages.  Also experiemented with the ignition curves as the aluminum heads were preferring something different in this area as compared to the iron heads.   The carb and ignition changes now has the engine peaking at 540+ HP at 6200 rpms.  And the current combination is now 313.1 points ahead of its 2009 EMC score which now has it slowly moving up in last years rankings.  At this point the engine has now overtaken the Ford 427 SOHC and the two Chrysler Hemis that were immediately ahead of the Y in the 2009 EMC rankings.  Here’s a graph showing the current horsepower and torque curves.  Keep in mind that this is still a pump gas engine and all testing is being performed through a set of mufflers.  Next on the list is getting back to the exhaust and doing some more work in that area with Geoff Mummert’s help but that will take place sometime after Columbus.

Lorena, Texas (South of Waco)

Your score is up from last year and other contestants scores this year should be lower due to the dual plane intake requirement and 6500 RPM test limit. All in all should be better than last time.

Keep up the great work!

http://ford-y-block.com 

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