So, what would happen if you took a set of OOTB Stealth heads.....and.......
Stripped them
Put 'em on a flowbench
Checked the valve stem diameters and the valve heads for roundness
Checked valve guide clearance
Back cut the valves
Do a rough performance valve job in the heads and set valve installed heights + or - .001"
Do combustion chamber, bowl and port clean up
Do a finish valve job
Re-flow the cylinder heads
Note any big flow discrepancies and send them back to the grinding bench
Re-flow the heads
Grind extra pushrod clearance along the intake ports for 1.6 rockers and 3/8 pushrods
CC the heads
Mill the heads
Measure the valve springs for proper pressure
Clean the heads and components, lube the guides and valve stems
Assemble the heads and set the spring installed heights
What would incidentally happen to the flow rates of those heads? Well...............
Lift............OOTB IN/EX cfm......Prepped IN/EX cfm
.100...........70/57.........................75/59
.200.........148/114.....................152/128
.300.........210/159.....................216/172
.400.........248/193.....................263/208
.500.........268/218.....................288/236
.600.........277/234.....................299/256
.700.........278/244.....................305/268
Stripped them
Put 'em on a flowbench
Checked the valve stem diameters and the valve heads for roundness
Checked valve guide clearance
Back cut the valves
Do a rough performance valve job in the heads and set valve installed heights + or - .001"
Do combustion chamber, bowl and port clean up
Do a finish valve job
Re-flow the cylinder heads
Note any big flow discrepancies and send them back to the grinding bench
Re-flow the heads
Grind extra pushrod clearance along the intake ports for 1.6 rockers and 3/8 pushrods
CC the heads
Mill the heads
Measure the valve springs for proper pressure
Clean the heads and components, lube the guides and valve stems
Assemble the heads and set the spring installed heights
What would incidentally happen to the flow rates of those heads? Well...............
Lift............OOTB IN/EX cfm......Prepped IN/EX cfm
.100...........70/57.........................75/59
.200.........148/114.....................152/128
.300.........210/159.....................216/172
.400.........248/193.....................263/208
.500.........268/218.....................288/236
.600.........277/234.....................299/256
.700.........278/244.....................305/268
