Stan
I am trying to use Blair's and time area.
Nowhere's does it need flow numbers.
Sorry, I just looked and the head I would use on this example
has a 2.23" intake valve (432 cfm @ .800")
and while I am correcting myself the exhaust valve is 1.72".
Stan ,
your Compression Ratio + VE% + Head CFM is already included ( sort of hidden inside )...
inside your desired 900 Peak HP at 7500 RPM
and inside your Peak TQ = 630.24 ( BMEP = 177.645 )
535 ci Pontiac engine for this example.
bore = 4.350", stroke = 4.500", rod = 6.700", cr = ??? (Pump gas), ( i used 10.25 and 11.0:1 CR )
Intake Valve = 2.230", Exhaust Valve = 1.720"
Maximum Head CFM @28in. = 431.99999455 to 462.61053223 CFM at 111.62117 % VE
Maximum Piston CFM = 962.46928032 occurs at 73.077765 degrees ATDC
Minimum recommended Flowbench Test Pressure = 62.4 inches vertical Manometer Water Column
Maximum Piston Velocity = 9325.689975 FPM occurs at 73.077765 degrees ATDC
Average Piston Velocity = 5625.000000 in Feet Per Minute
Piston Depth at 73.077765 degree ATDC= 1.950290 inches Cylinder Volume = 474.9729 CC
Crank Angle at which Rod and Crank axis form a 90 degree angle = 71.4368729 ATDC
Maximum TDC Rod Tension GForce = 4802.0155 G's Acceleration Ft/Sec^2 = 154500.2788
Maximum BDC Rod Compression GForce = 2387.5943 G's Acceleration Ft/Sec^2 = 76818.5744
i get these minimum Cam Specs : (* Race only Engine with 10.25:1 CR )
0.8617 = Intake Valve Lift 278.0 Duration @0.050"
0.8334 = Exhaust Valve Lift 298.0 Duration @0.050"
LSA = 108.118 degrees
* Specs adjusted for ValveTrain Deflection = 0.0000 Intake Lash= 0.0250 Exhaust Lash= 0.0250
.... * minimum Cam Specs required to achieve 900 Peak HP @ 7500 RPM
i get these maximum Cam Specs : (* Professional Race only Engine with 11.0:1 CR )
0.97059 = Intake Valve Lift 284.0 Duration @0.050" ( Time-Area = 0.9569 Lift )
0.90592 = Exhaust Valve Lift 300.0 Duration @0.050" ( Time-Area = 0.8932 Lift )
LSA = 112.982 degrees
* Specs adjusted for ValveTrain Deflection = 0.0000 Intake Lash= 0.0250 Exhaust Lash= 0.0250
* maximum Cam Specs required to achieve +900 Peak HP and higher than 900 Peak HP @ 7500 RPM
Cylinder Head Intake Port Flow @28 in. = 432.0000 -to- 462.6105 CFM at 0.97059 Lift (111.62117 Ve%)
Cylinder Head Exhaust Port Flow @28 in. = 310.1252 -to- 339.3970 CFM at 0.90592 Lift (no Flow Pipe)
"has a 2.23" intake valve (432 cfm @ .800")
and while I am correcting myself the exhaust valve is 1.72"
i realize you only want to use Blair's Equations/Methods !
i'd like to see how my Calcs compare to Blair's Methods ?
.... very interesting Thread !
.... waiting to see your Data results from Blair's methods