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#1---Head Flow Charts & Comparisons

10/6/2011

There  are enough flow numbers on our website to keep everyone busy for a while. The numbers are from our in-house flow bench. It is a custom bench and the flow figures are generated using orifice plates and then corrected for atmospheric conditions for each test. All tests were done at 28".    Now your next question is........ What will they flow on my bench? The answer is that we don't know. That is why we supply these charts and again, I repeat, again, all flow benches do not flow the same! Benches can show a difference of about 3to 5%. 5% at 300CFM is a difference of 15CFM. We have seen benches off 6 to 8 %. 8% at 300CFM is 24CFM. An extra 24CFM will really help a guy sell heads! How does this make you feel? I know, you feel cheated, so do we, but this is what we have to deal with in this business.   So how do you go about determining a good port? After 50 years of flowing head the industry still does not have a good answer to this. Here are some indicators to help.   1. Know this for sure. If most legitimate shops are getting 350CFM airflow out of a certain head and someone suddenly starts advertising 390CFM...... that is just what it is, advertising (or a mis-used flow bench)   2. Clue to a good port. The flow should rise very quickly. For example: Lets take a head that flows a maximum of 300CFM. The  lower the lift at which that number is reached, the better the port design. If maximum flow is reached at .500" lift the head will produce a better power curve than if the valve must be opened to .700" lift or more to get the flow.  A head that flows good quickly is what we call our "Fat Flow" ports.   3. If the flow continues to increase above you maximum lift the port volume is too big and the port is poorly designed and will therefore have a lower velocity and poor power output.  4. The smallest port volume with the most flow quickly reached is the best designed port.  5. The flow numbers above about 95% of your net lift do a lot more for your ego than they do for your power curve......But, they look good in ads.  6. Flow numbers by themselves are a poor way to judge a head. Important power producing features like velocity and wet flow cannot be seen in flow numbers.  7. Keep in mind that we are constantly working on head development and these numbers can change. Or, maybe we should just buy a new flow bench. It would be a lot less work, and we could sell more head, because the numbers would look bigger.  We spend part of every week doing R&D on head porting and design all year long.      8. The charts below show the difference between stock flow numbers as well as the flow after our modifications are made. The actual gain in flow is much more important than what the flow "number" is.         You may notice as you wander around our website that from time to time there may be flow charts of the same head on two different pages. The "Stock" flow numbers may not be exactly the same on each page. This is not a mistake. We actually do the stock flow test on the exact head that we are going to port. Flow numbers routinely vary a little from head to head so it is inevitable that the numbers will vary a little.  Aluminum Heads(Iron heads at bottom of page)          Small Block Edelbrock RPM "LA" Heads              Hughes 4600 / Edelbrock 60779                        Small Block "LA" Edelbrock Heads                         Super Prepped (Hand Work)                                    # HUG4600-P Test Stock Int cfm Super Prep Int cfm Int cfm Gains   Stock Exh cfm Super Prep Exh cfm Exh cfm Gains .100" 67.6 71.6 +4         .200" 128.0 138.5 +10.5   84.4 92.9 +8.5 .300" 185.2 192.6 +7.4   129.8 137.6 +7.8 .350" 208.1 215.7 +7.6   142.6 153.9 +11.3 .400" 227.1 235.8 +8.7   151.2 168.5 +17.3 .450" 240.4 253.5 +13.1   157.2 175.2 +18 .500" 253.7 254.1 -.4   161.3 176.3 +15 .550" 256.4 253.3 -3.1   163.3 176.3 +13 .600" 257.7 252.0 -5   164.2 176.3 +12.1 .650" 251.7 252.0 +.3   164.9 176.3  +11.4                             Small Block "LA" Edelbrock Heads                  C.N.C. Super Prepped (C.N.C. & Hand Work)                                        #HUG4600-SCP Test Stock Int cfm CNC Prep Int cfm Int cfm Gains   Stock Exh cfm CNC Prep Exh cfm Exh cfm Gains .100" 67.6 72.1 +4.5         .200" 128.0 150.4 +22.5   84.4 87.8 +3.4 .300" 185.2 209.5 +24.3   129.8 136.5 +6.7 .350" 208.1 231.3 +23.2   142.6 153.0 +10.4 .400" 227.1 248.5 +21.4   151.2 169.1 +17.9 .450" 240.4 257.0 +16.6   157.2 178.4 +21.2 .500" 253.7 252.9 -.8   161.3 184.2 +22.9 .550" 256.4 253.2 -3.2   163.3 186.6 +23.3 .600" 257.7 254.4 -3.3   164.2 188.7 +24.5 .650" 251.7 256.2 +4.5   164.9 189.8  +24.9                                                      Small Block "LA" Edelbrock Heads                                     Intake Port Volume 199cc                   Fully C.N.C. Ported with 2.08" Intake Valves                                            # HUG4600-S3              Lift Stock Intake CFM CNC'd Intake CFM CFM Gained   Stock Exhaust CFM CNC'd Exhaust CFM CFM Gained .100 69.5 71.1 1.6     76.0   .200 135.6 146.2 9.6   109.0 118.1 9.1 .300 189.9 214.9 25.9   139.2 155.6 16.4 .350 214.0 240.6 26.6   147.6 165.1 17.5 .400 228.9 262.5 33.6   158.6 173.4 14.8 .450 234.7 276.0 41.3   164.6 181.2 16.6 .500 241.4 286.3 44.9   169.9 189.3 19.4 .550 249.7 297.3 47.8   172.1 196.4 24.3 .600 255.9 293.8 37.9   176.1 197.9 21.8 .650 255.9 295.6 39.7   179.9 198.1 18.2 .700 261.3 297.7 36.4   182.3 200.1 17.8 .750 263.2 299.6 36.4          Small Block Edelbrock RPM Magnum Heads          Hughes 4610 / Edelbrock 61779             Edelbrock Small Block RPM Magnum                   Super Prepped  (Hand Work)                              # HUG4610-P Test Stock Intake Hughes Prepped Intake CFM Gained   Stock Exhaust Hughes Prepped Exhaust CFM Gained .100 69.3 72.7 +3.4         .200 125.8 137.9 +12.1   82.1 82.1 0 .300 182.5 188.5 +6.0   133.3 132.2 -1 .350 206.4 212.9 +6.5   152.5 148.3 -4.1 .400 228.3 235.1 +6.8   167.3 165.1 -2.2 .450 243.9 257.0 +13.1   176.3 176.3 0 .500 247.2 262.3 +15.1   184.0 185.1 +1.1 .550 255.0 268.7 +13.7   189.3 190.3 +1.0 .600 258.3 270.1 +11.8   192.5 195.6 +.61 .650 259.0 272.0 +13.0   194.6 198.8 +4.2 .700 259.6 274.3 +14.7   197.7 201.8 +4.1               Edelbrock Small Block RPM Magnum                  C.N.C. Super Prepped  (C.N.C. & Hand Work)                              # HUG4610-SCP Test Stock Intake Hughes Prepped Intake CFM Gained   Stock Exhaust Hughes Prepped Exhaust CFM Gained .100 67.6 72.7 +5.1         .200 124.6 150.7 +26.1   78.3 89.7 +11.4 .300 181.5 206.4 +24.9   132.2 138.7 +6.5 .350 204.2 230.0 +25.8   147.2 162.3 +15.1 .400 224.9 249.8 +24.9   162.3 177.4 +15.1 .450 236.2 259.6 +23.4   171.8 191.4 +19.6 .500 246.5 265.5 +19.0   180.8 199.8 +19.0 .550 247.8 267.3 +19.5   187.2 204.9 +17.7 .600 244.5 265.0 +20.5   192.5 209.1 +16.6 .650 245.2 265.9 +20.7   196.7 212.2 +15.5                   Edelbrock Small Block RPM Magnum               Fully C.N.C Ported with 2.08" intake valves                                   # HUG4610-S3 Test Stock Intake Hughes CNC Intake CFM Gained   Stock Exhaust Hughes CNC Exhaust CFM Gained .100 69.3 75 +5.7     62   .200 125.8 158.1 +32.3   82.1 86.0 +3.9 .300 182.5 214.3 +31.8    133.3 140.4 +7.1 .350 206.4 240.6 +34.2    152.5 161.6 +9.1 .400 228.3 264.3 +36.0    167.3 181.2 +13.9 .450 243.9 282.9 +39.0    176.3 198.9 +22.6 .500 247.2 292.5 +45.3    184.0 210.3 +26.3 .550 255.0 297.3 +42.3    189.3 219.5 +30.2 .600 258.3 299.1 +40.8    192.5 226.1 +33.6 .650 259.0 298.9 +39.9   194.6 230.4 +35.8 .700 259.6 304.0 +44.4   197.7 233.6 +35.9          Big Block Edelbrock RPM Heads          Hughes 4650 / Edelbrock 60929                             Edelbrock Big Block RPM                       Super Prepped (Hand Work)                                   # HUG4650-P Test Stock Intake CFM Prepped Intake CFM CFM Gained   Stock Exhaust CFM Prepped Exhaust CFM CFM Gained .100" 74.0 75.1 +1   67.9 75.8 +8 .200" 147 152.3 +6   117.2 132.2 +17 .300" 209 225 +14   149.4 166.1 +17 .350" 230 239.0 +12   167.0 183.9 +16 .400" 247 264.8 +18   179.0 199.1 +20 .450" 256 275.6 +19   190.6 209.8 +19 .500" 268 284.0 +16   202.3 221.0 +19 .550" 281.4 285.6 +4   213.1 231.2 +18 .600" 282.0 286.0 +4   220.9 238.8 +18 .650" 280.0 285.6 +5   225.9 247.5 +22                                           Edelbrock Big Block RPM                       C.N.C. Super Prepped (C.N.C. & Hand Work)                                   # HUG4650-SCP                                                           Edelbrock Big Block RPM                                     Fully C.N.C. Ported                                       # HUG4650-S3                          Lift 2.14" OEM Inrtake CNC Stage3 Intake Gain   OEM CNC Stage3 Exhaust Gain .100" 74 78 +4         .200" 147 1.68 +21   117 115 -2 .300" 209 233 +24    149 157 +12 .400" 247 280 +33    179  194  +15 .500" 268 309 +41    203  219  +16 .600" 275 318 +43    217  223  +5 .700" 278 322 +44    222  228 +6                             Big Block Edelbrock Victor Heads              Standard 440 Size Intake Ports              Hughes 4656 / Edelbrock 77929                                  Edelbrock Big Block Victor (440 Port Size)                                Super Prepped (Hand Work)                                          # HUG4656-P                                                  Edelbrock Big Block Victor (440 Port Size)                 C.N.C.Super Prepped (C.N.C. & Hand Work)                                     # HUG4656-SCP                                                                Edelbrock Big Block Victor (440 Port Size)                                         Fully C.N.C. Ported                                          # HUG4656-S3                           Port Volume: INT 313cc EXH 84cc Lift Stock Intake CFM CNC'd Intake CFM CFM Gained Stock Intake CFM CNC'd Exhaust CFM CFM Gained .100 74.4 81.2 6.8       .200 137.0 170.9 33.9 99.4 101.0 1.6 .300 191.7 235.1 43.4 158.1 165.1 7.0 .350 220.1 267.8 47.7 180.8 193.5 12.7 .400 247.8 290.4 42.6 198.8 217.4 18.6 .450 273.9 313.0 39.1 215.3 234.2 18.9 .500 293.8 320.3 26.5 224.9 248.6 23.7 .550 309.5 331.9 22.4 230.9 260.3 29.4 .600 310.7 342.0 31.3 235.9 271.5 35.6 .650 311.0 349.6 38.6 239.0 278.8 39.8 .700 316.4 354.7 38.3 240.7 284.6 43.9 .750 318.6 356.3 37.7 241.9 288.5 46.6                                                           Big Block Edelbrock Victor Heads              Max Wedge Size Intake Ports              Hughes 4658 / Edelbrock 77949                    Edelbrock Big Block Victor (Max WedgePort Size)                                Super Prepped (Hand Work)                                          # HUG4658-P                                                  Edelbrock Big Block Victor (Max WedgePort Size)                     C.N.C.Super Prepped (C.N.C. & Hand Work)                                       # HUG4658-SCP                                                          Edelbrock Big Block Victor (Max WedgePort Size)                                      Fully C.N.C. Ported                                           # HUG4658-S3  Lift Stock Intake CFM CNC'd Intake CFM CFM Gained Stock Intake CFM CNC'd Exhaust CFM CFM Gained .100 74.4 79 5       .200 137.0 171 34 99.4 101.0 1.6 .300 191.7 235 43 158.1 165.1 7.0 .350 220.1 268 48 180.8 193.5 12.7 .400 247.8 293 45 198.8 217.4 18.6 .450 273.9 317 43 215.3 234.2 18.9 .500 293.8 327 33 224.9 248.6 23.7 .550 309.5 341 31 230.9 260.3 29.4 .600 310.7 352 42 235.9 271.5 35.6 .650 311.0 364 53 239.0 278.8 39.8 .700 316.4 372 56 240.7 284.6 43.9 .750 318.6 379 60 241.9 288.5 46.6                                                                    INDY Cylinder Heads 440 EZ (Standard 440 Intake Port Size)    HUG4950/ IND440-H1-SEZ-1     INDY Big Block440-EZ (Standard 440 Port Size)               Super Prepped (Hand Work)                         # HUG 4950-P Test Stock Indy Intake Port Intake Port with Super Prep CFM Gained      Stock Indy Exhaust Port Exhaust Port with Super Prep CFM Gained .100 70 71 +1   59 61 +2 .200 128 153 +25   101 106 +5 .300 188 209 +21   138 145 +7 .350 215 231 +16   153 160 +7 .400 236 258 +22   168 179 +11 .450 261 277 +16   182 191 +9 .500 276 293 +17   196 203 +7 .550 287 308 +21   212 216 +4 .600 294 319 +25   217 223 +6 .650 299 325 +26   224 230 +6 .700 303 329 +26   230 234 +6                      INDY Cylinder Heads 440 EZ   (Max Wedge Intake Port Size)              HUG4950MW           INDY Big Block440-EZ (Max Wedge Port Size)                  Fully CNC Ported                # HUG 4950-MW-S3           Use the chart below to view flow numbers.                   Flow Comparisons Between the  INDY EZ-295 vs. Hughes C.N.C's INDY EZ's  This chart is to show the difference in INDY EZ MaxWedge CNC vs. Hughes Max Wedge CNC on the same head.     Intake Port Volumes          Exhaust Port Volumes   INDY      Hughes                   INDY        Hughes    318         298                           81                79     Test Indy Intake Hughes Intake Gain in CFM   Indy Exhaust Hughes Exhaust Gain in CFM .100" 72 77 +5         .200" 146 159 +12   91 88 -3 .300" 215 231 +16   136 135 -1 .350" 247 264 +17   155 155 0 .400" 276 283 +7   174 177 +3 .450" 297 304 +7   191 197 +6 .500" 315 323 +8   203 218 +15 .550" 331 339 +7   218 230 +12 .600" 341 345 +4   227 241 +14 .650" 349 352 +3   235 248 +13 .700" 351 352 +1   241 252 +11      Iron Heads         Magnum EQ or "Iron Ram" style heads               HUG4666 & 4668   The chart below is a flowchart comparing the Iron ram          head to the OEM head and the R/T head                   INTAKE                                         EXHAUST                     Valve Lift Magnum OEM Iron Ram Iron Ram R/T LA '576 Magnum OEM Iron Ram R/T LA '576   1.920" 1.920" 2.02" 2.02" 2.02" 1.620" 1.620" 1.620" 1.60" .100 51.2 68.2 n/a 61.4 69.0 55.1 57.2 65.9 51.0 .200" 121.1 124.1 119.0 119.2 118.0 109.0 114.1 120.2 103.0 .300" 181.5 179.6 177.0 169.3 176.0 148.4 155.3 153.7 131.0 .400" 207.5 213.8 224.0 211.0 204.0 170.8 180.0 168.0 140.0 .500" 209.0 227.0 247.0 220.6 212.0 176.2 187.3 174.0 141.0 .600" 208.4 233.1 240.0 220.6 210.0 178.4 188.7 176.0 142.0                                   Magnum "Iron Ram" Super Prepped Heads     HUG HPHD-MAG1-SP              Lift CFM @ 28" correction .100" 70.5 .200" 140.7 .300" 202.1 .350" 223.7 .400" 239.0 .450" 258.2 .500" 268.0 .550" 264.4 .600" 250.4 .650" 245.0                               Magnum "Iron Ram"       Fully Ported Heads     HUG HPHD-MAG1-S1 Lift CFM @ 28" correction .100" 67 .200" 127 .300" 187 .350" 220 .400" 241 .450" 268 .500" 285 .550" 296 .600" 298 .650" 299                              RHS "X" Head  Small Block "LA" & Magnum Style HUG20300 & 20301                  RHS   "X" Heads   (LA & Magnum heads use the same ports)    Stock with 1.92" int and 1.60" Exhaust Lift intake Exhaust .100" 66   .200" 116 91 .300" 177 138 .350" 203 155 .400" 224 167 .450" 239 171 .500" 252 174 .550" 262 176 .600" 263 178 .650" 263 179 .700" 275 179  Note: These are average numbers. Stock ports can vary by +/- 6 cfm in the same head.                     RHS "X" Heads           Super Prepped (Hand Work)  Uses 2.02" intake and stock exhasut valves Lift Stock Super Prepped CFM Change   Stock Super Prepped Change .100 66 74 +8         .200 116 146 +40   91 89 -2 .300 177 202 +25   138 139 +1 .350 203 225 +22   155 158 +3 .400 224 241 +17   167 173 +6 .450 239 258 +19   171 181 +10 .500 252 268 +16   174 187 +13 .550 262 271 +9   176 196 +15                      Big Block OEM Iron Heads          Big Block Iron '452      Stage 3 Fully Ported    Lift Ported Intake cfm   Ported Exhaust cfm .100 75.8     .200 155.0   76.4 .300 213.9   125.4 .350 227.3   142.9 .400 243.4   162.3 .450 258.4   177.4 .500 269.4   190.3 .550 278.5   199.8 .600 286.0   205.9 .650 289.4   211.1 .700 291.3   211.1              Undercover "Stealth" Porting Small Block "LA" Iron Heads           Stealth-ported" S/B Oval Track Heads       '596 casting number OEM valves 1.88-1.60               Stealth Valves 2.02-1.60     OEM Stealth CFM   OEM Stealth CFM   INT INT Change      Exh Exh Change .100" 66 71 +5   51 80 +29 .200" 89 144 +55   103 124 +21 .300"   136 192 +56   131 149 +18 .350"   176 211 +35   136 156 +20 .400" 184 226 +42   140 160 +20 .450" 186 231 +45   142 168 +26 .500" 184 223 +39   141 168 +27 .550" 183 218 +35   142 168 +26  Note: These flow figures are representative of improvements  that can be made with stealth porting on LA heads. Actual flow will vary with different casting numbers.