vannik wrote: ↑Sat Jun 02, 2018 3:33 amThis is the issue I have with the current "prescribed" STA values, I do not believe the targets for a 2 valve engine should be the same as for a 4 valve engine. And the various 2 valve layouts should each have separate set of target values. As I said before, there are tuners that developed their own values and use it very successfully but do not share. DV probably has the largest database of all by a large percentage but understandably he will not share as he makes his income from it.
PipeMax v4.00 calculates an easy 904.9 Peak HPVincenzo :
Intake = 52/86 318 duration 0.972441 Lift 107.0 CL
Exhaust= 88/56 324 duration 1.047244 Lift 106.0 CL
LSA = 106.5 deg
Overlap= 108.0 deg
Despite the near matching STA's, when all the relevant data is run through EngMod4T and Blair's
software, both computed outputs fall way short of the target 900 bhp at the stipulated 7500 rpm.
and can make a lot more HP with Vac-Pump + Lite Oil + Race Oil Pan
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Camshaft = Solid Roller Lifter
600 RPM/Sec Dyno Test Level=10
Peak HorsePower @ 7500 RPM 904.9
Peak Torque Lbs-Ft @ 5800 RPM 702.1
i get this from my Time-Area equations ( different equations than Blair )
Intake Time Area TQ Valve Lift = 0.953882 Exhaust Time Area TQ Valve Lift = 0.879506
Intake Time Area HP Valve Lift = 1.047193 Exhaust Time Area HP Valve Lift = 0.940888
Cam Specs might be this instead :
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--------------------------------- Recommended Camshaft Specs at 0.050” inch Lobe Lift -------------
Cam Lobe Separation Angle (LSA) 108.118
Camshaft Intake Valve Lift 0.97629
Camshaft Exhaust Valve Lift 0.88333
Camshaft Intake Duration 272.584
Camshaft Exhaust Duration 292.018
Camshaft Overlap Duration 66.066
* Specs adjusted for ValveTrain Deflection = 0.0000 Intake Lash= 0.0140 Exhaust Lash= 0.0140
... sort of max-effort with only 11:1 CR and 1 Carb on a Single-Plane Manifold
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535.02108289 Cubic Inches at 7500 RPM with Intake System = 110.62117 % PerCent Volumetric Efficiency
Complete Intake System Flow @28 in. = 428.1298 -to- 458.4661 CFM at 0.97059 Lift (1.00000 % VE Loss)
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. = 306.0206 -to- 334.9050 CFM at 0.89455 Lift (no Flow Pipe)
Dyno HP Weather Correction Equation = 8• SAE J607 (June1974) • STP • SuperFlow-FTQ • (Default)
Dyno Correction Factor= 1.0000000 Fuel Type = Gasoline • Race Gas • HP and Torque increase
Fuel BTU=19000.0 Air/Fuel Ratio=12.500000 BSFC=0.519804 Mixture Distribution= 90.0 Quality= 90.0
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Camshaft = Solid Roller Lifter
600 RPM/Sec Dyno Test Level=7 Level=8 Level=9 Level=10
Peak HorsePower @ 7500 RPM 871.4 882.5 893.6 904.9
Peak Torque Lbs-Ft @ 5800 RPM 670.5 684.7 693.3 702.1
HorsePower per CID 1.629 1.649 1.670 1.691
Torque per Cubic Inch 1.253 1.280 1.296 1.312
Peak Torque BMEP in psi 189.0 193.0 195.4 197.9
(1) 4-Barrell Carb CFM @ 1.5 inHg. 1296 1442 1515 1588
--------------------------------- Recommended Camshaft Specs at 0.050” inch Lobe Lift -------------
Cam Lobe Separation Angle (LSA) 108.118 108.501 108.982 109.419
Camshaft Intake Valve Lift 0.97629 1.01654 1.05846 1.10210
Camshaft Exhaust Valve Lift 0.88333 0.91975 0.95768 0.99716
Camshaft Intake Duration 272.584 274.552 276.534 278.530
Camshaft Exhaust Duration 292.018 294.124 296.243 298.378
Camshaft Overlap Duration 66.066 67.337 68.426 69.616
* Specs adjusted for ValveTrain Deflection = 0.0000 Intake Lash= 0.0140 Exhaust Lash= 0.0140
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* User's current Camshaft Specs : OverLap Duration = 64.30100
Lobe Separation Angle (LSA)= 112.00000 Camshaft Advanced = 3.88200 degrees
Intake Lobe CenterLine = 108.11800 Exhaust Lobe CenterLine = 115.88200
Intake Duration at 0.05000” Lobe Lift Exhaust Duration at 0.05000” Lobe Lift
Intake Duration = 278.58400 Exhaust Duration = 298.01800
Intake Open = 31.17400 BTDC Exhaust Open = 84.89100 BBDC
Intake Close= 67.41000 ABDC Exhaust Close= 33.12700 ATDC
Intake Rocker Ratio = 1.90000:1 Exhaust Rocker Ratio = 2.02000:1
Intake Lobe Lift = 0.510837 Exhaust Lobe Lift = 0.442847
Intake Valve Lift = 0.970590 Exhaust Valve Lift = 0.894550
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Intake System Flow Valve Lift = 1.087387 Exhaust System Flow Valve Lift = 0.989642
Intake Port Flow Valve Lift = 1.096436 Exhaust Port Flow Valve Lift = 0.982633
Intake Curtain Flow Valve Lift = 1.135719 Exhaust Curtain Flow Valve Lift = 1.013048
Intake Time Area TQ Valve Lift = 0.953882 Exhaust Time Area TQ Valve Lift = 0.879506
Intake Time Area HP Valve Lift = 1.047193 Exhaust Time Area HP Valve Lift = 0.940888
Intake Z-Factor Valve Lift = 1.060082 Exhaust Z-Factor Valve Lift = 0.989609
0.250 L/D Ratio Int Valve Lift = 0.557500 0.250 L/D Ratio Exh Valve Lift = 0.430000
Note : the Valve Curtain Area will equal the Valve Area @ 0.250 Valve Lift/Diameter Ratio
Intake Mach Z-Factor = 48.5375 % SOS Exhaust Mach Z-Factor = 68.2787 % SOS
Mach Z-Factor definition = PerCent % of the Speed of Sound ( SOS ) at the Valve's Curtain Area
Mach Z-Factor Valve Lift = calculated from Speed of Sound velocity thru Valve Curtain Areas
System Flow Valve Lift = calculated from Intake and Exhaust System Flow and Valve Diameters
Port Flow Valve Lift = calculated from Intake and Exhaust Port's Flow and Valve Diameters
Curtain Flow Valve Lifts = calculated from Flow thru the Intake and Exhaust Valve Curtain Areas
Time Area Valve Lifts = calculated from User's Camshaft Durations, Curtain Areas, RPM Range
DCR Cylinder Volume CC = 838.869367 Dynamic Compression Ratio = 8.654420:1
DCR Effective Stroke = 3.4445 inches Valve Lash Compression Ratio = 7.701312:1
Static Compression Ratio = 11.000000:1 Ve% + Lash Compression Ratio = 8.596294:1
Cranking Psi @ 150 RPM = 157.4 Psi -to- 180.9 Psi @ 260 RPM ( depending on Ring seal / Piston Rock )