valve size and duration?
Moderator: Team
valve size and duration?
How do you know how much duration and lift you need with a certain valve size to achieve the rpm that you want. I thought there was a formula around here but I cant find it when I do a search. Im building a 496 with a 2.17 intake valve size and want peak hp around 6500. Anyone know about how much duration and lift I would need to get there.
There was a formula for a curtain area and port size here not too long ago.
I would think the min. port cross section would be included in this, as it will pay a part in the peak rpm.
I would think the min. port cross section would be included in this, as it will pay a part in the peak rpm.
67 camaro
girly rollers on pumpgas:
420 - 641hp BretBauerCam, 1.39, 9.79 @ 137.5
383 - 490hp 224/224, 1.56, 10.77 @ 124.6
502 - 626hp 252/263, 049s 1.44, 10.08 @ 132.7
62 Nova cruiser
383/200-4R/12-bolt w 373s
224/224 HR cam
1.57 10.97 @ 121.2
girly rollers on pumpgas:
420 - 641hp BretBauerCam, 1.39, 9.79 @ 137.5
383 - 490hp 224/224, 1.56, 10.77 @ 124.6
502 - 626hp 252/263, 049s 1.44, 10.08 @ 132.7
62 Nova cruiser
383/200-4R/12-bolt w 373s
224/224 HR cam
1.57 10.97 @ 121.2
-
- Vendor
- Posts: 3647
- Joined: Sat Feb 14, 2004 4:04 pm
- Location: Abbeville, LA
- Contact:
with a 2.170 Intake Valve
about .050" less Valve Lift on Camshaft with 2.300 vs 2.170
sorry for the way Data comes out formatted in this Post
Code: Select all
496.049 Cubic Inches @ 6500 RPM with 100.0 % Volumetric Efficiency PerCent
Required Intake Flow between 298.9 CFM and 316.4 CFM at 28 Inches
Required Exhaust Flow between 241.6 CFM and 258.9 CFM at 28 Inches
600 RPM/Sec Dyno Test Low Normal Best
Peak HorsePower 688.2 698.8 709.3
Peak Torque Lbs-Ft 616.5 625.9 635.4
HorsePower per CID 1.387 1.409 1.430
Torque per Cubic Inch 1.243 1.262 1.281
BMEP in psi 187.4 190.3 193.2
Carb CFM at 1.5 in Hg. 933 1038 1143
Target EGT= 1298 degrees F during 4 second 600 RPM/Sec Dyno accel. test
Octane (R+M)/2 Method = 104.1 to 106.8 Octane required range
Air Standard Efficiency = 62.989 % for 12.000:1 Compression Ratio
Peak HorsePower calculated from Cylinder Head Flow CFM only
600 RPM/Sec Dyno Test Lowest Average Best Potential
Head Flow Peak HP = 431.6 680.0 762.7
----- Engine Design Specifications -----
Engine Size CID = 496.049 Intake Valve Net Area = 3.589
CID per Cylinder = 62.006 Intake Valve Dia. Area = 3.698
Rod/Stroke Ratio = 1.444 Intake Valve Stem Area = 0.109
Bore/Stroke Ratio = 1.014 Exhaust Valve Net Area = 2.667
Int Valve/Bore Ratio = 0.503 Exhaust Valve Dia. Area = 2.776
Exh Valve/Bore Ratio = 0.436 Exhaust Valve Stem Area = 0.109
Exh/Int Valve Ratio = 0.866 Exh/Int Valve Area Ratio = 0.751
Intake Valve L/D Ratio= .323 Exhaust Valve L/D Ratio= .362
CFM/Sq.Inch = 80.8 to 85.6 CFM/Sq.Inch =87.0 to 93.3
Curtain Area -to- Valve Area Convergence Intake Valve Lift = .543
Curtain Area -to- Valve Area Convergence Exhaust Valve Lift = .470
Intake Valve Margin CC's Exhaust Valve Margin CC's
1.00 CC = 0.0165 1.00 CC = 0.0220
0.50 CC = 0.0083 0.50 CC = 0.0110
0.25 CC = 0.0041 0.25 CC = 0.0055
0.10 CC = 0.0017 0.10 CC = 0.0022
------- Piston Motion Data -------
Average Piston Speed (FPM)= 4604.16 in Feet Per Minute
Maximum Piston Speed (FPM)= 7658.58 occurs at 72.669 Degrees ATDC
Piston Depth at 72.669 degree ATDC= 1.8370 inches Cylinder Volume= 439.2 CC
Maximum TDC Rod Tension GForce= 3433.34 G's
Maximum BDC Rod Compression GForce= 1666.79 G's
------- Current Camshaft Specs @ .050 -------
IntOpen= 22.50 IntClose= 62.50 ExhOpen= 70.00 ExhClose= 30.00
Intake Duration @ .050 = 265.00 Exhaust Duration @ .050 = 280.00
Intake CenterLine = 110.00 Exhaust CenterLine = 110.00
Compression Duration= 117.50 Power Duration = 110.00
OverLap Duration = 52.50 Lobe Center Angle (LCA)= 110.00
Camshaft installed Straight Up = 0.00 degrees
-Recommended Camshaft Valve Lift- - Induction System Tuned Lengths -
Minimum Normal Maximum Best Length= 14.088 2nd= 11.089
Intake = 0.744 0.801 0.882 3rd Best= 8.997 4th Best= 7.569
Exhaust = 0.732 0.788 0.867 Plenum Runner Max Entry Area = 4.917
Max-effort Intake Lift = 0.924 Minimum Plenum Volume CC = 1232.9
Max-effort Exhaust Lift = 0.908 Minimum Plenum Volume CID= 75.2
Minimum Intake Valve Lift to prevent Choke = .801 Lift @ 6500 RPM
------- Operating RPM Ranges of various Components -------
Camshaft Intake Lobe RPM = 6701 Exhaust Lobe RPM = 6676
Camshaft's Intake and Exhaust Lobes operating RPM range = 4694 to 6694
Note=> Lobe RPMs are valid only for conventional 2-Valve Pushrod Engines
Current (Intake Valve Curtain Area -VS- Time) Choke RPM = 5677 RPM
Intake Valve Area + Curtain Area operating RPM Range = 4113 to 6113 RPM
Intake Valve Diameter RPM Range = 4677 to 6677
Intake Flow CFM @28in RPM Range = 4483 to 6483
with a 2.300 Intake Valve =>
Intake Valve L/D Ratio= .304 Exhaust Valve L/D Ratio= .362
CFM/Sq.Inch = 71.9 to 76.2 CFM/Sq.Inch =80.0 to 88.0
Curtain Area -to- Valve Area Convergence Intake Valve Lift = .575
Curtain Area -to- Valve Area Convergence Exhaust Valve Lift = .470
Intake Valve Margin CC's Exhaust Valve Margin CC's
1.00 CC = 0.0147 1.00 CC = 0.0220
0.50 CC = 0.0073 0.50 CC = 0.0110
0.25 CC = 0.0037 0.25 CC = 0.0055
0.10 CC = 0.0015 0.10 CC = 0.0022
------- Piston Motion Data -------
Average Piston Speed (FPM)= 4604.16 in Feet Per Minute
Maximum Piston Speed (FPM)= 7658.58 occurs at 72.669 Degrees ATDC
Piston Depth at 72.669 degree ATDC= 1.8370 inches Cylinder Volume= 439.2 CC
Maximum TDC Rod Tension GForce= 3433.34 G's
Maximum BDC Rod Compression GForce= 1666.79 G's
------- Current Camshaft Specs @ .050 -------
IntOpen= 22.50 IntClose= 62.50 ExhOpen= 70.00 ExhClose= 30.00
Intake Duration @ .050 = 265.00 Exhaust Duration @ .050 = 280.00
Intake CenterLine = 110.00 Exhaust CenterLine = 110.00
Compression Duration= 117.50 Power Duration = 110.00
OverLap Duration = 52.50 Lobe Center Angle (LCA)= 110.00
Camshaft installed Straight Up = 0.00 degrees
-Recommended Camshaft Valve Lift- - Induction System Tuned Lengths -
Minimum Normal Maximum Best Length= 14.088 2nd= 11.089
Intake = 0.702 0.756 0.832 3rd Best= 8.997 4th Best= 7.569
Exhaust = 0.691 0.744 0.818 Plenum Runner Max Entry Area = 4.917
Max-effort Intake Lift = 0.871 Minimum Plenum Volume CC = 1232.9
Max-effort Exhaust Lift = 0.857 Minimum Plenum Volume CID= 75.2
Minimum Intake Valve Lift to prevent Choke = .756 Lift @ 6500 RPM
------- Operating RPM Ranges of various Components -------
Camshaft Intake Lobe RPM = 6814 Exhaust Lobe RPM = 6789
Camshaft's Intake and Exhaust Lobes operating RPM range = 4808 to 6808
Note=> Lobe RPMs are valid only for conventional 2-Valve Pushrod Engines
Current (Intake Valve Curtain Area -VS- Time) Choke RPM = 6017 RPM
Intake Valve Area + Curtain Area operating RPM Range = 4359 to 6359 RPM
Intake Valve Diameter RPM Range = 5501 to 7501
Intake Flow CFM @28in RPM Range = 4483 to 6483
about .050" less Valve Lift on Camshaft with 2.300 vs 2.170
sorry for the way Data comes out formatted in this Post
-
- HotPass
- Posts: 494
- Joined: Sun Oct 30, 2005 1:25 am
- Location: Phoenix AZ area
-
- Vendor
- Posts: 3647
- Joined: Sat Feb 14, 2004 4:04 pm
- Location: Abbeville, LA
- Contact:
this LINKMaxrace, which version of your software are you using to produce this data? Looks awesome!
http://www.maxracesoftware.com/pipemax_win.htm
starting at *** Version 3.0 ***
towards the middle of page to the bottom
one day i'll take the time to figure out how to Post
this Data so it doesn't get Formatted so badly
its too much Data to Post anyway..takes up too much of
SpeedTalk's valuable Web space