#310---- Head Flow Comparisons Updated 11/2009
Differences in Flow Benches

1/11/2010


                  
 Head Flow Number Comparisons     
     

  Here are enough flow numbers 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 cannto 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.   


 Edelbrock LA Stage 3 CNC w/ 2.08" intake valve  

                                
Stage 3 CNC Ported Heads with 2.08" Valves
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        


 

Edelbrock Small Block RPM Magnum
Hughes Super Prepped w/ 2.02" Valve
 

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
Hughes Fully CNC Ported w/ 2.08" VALVE
 

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

 

 


BB Edelbrock RPM Stage 3 CNC w/ 2.190" valve 

                         

Lift

2.14" OEM Inrtake

CNC Stage3 Intake

Gain

 

OEM

CNC Stage3 Exhaust

Gain

.100"

74

79

+5

 

 

 

 

.200"

147

158

+11

 

98

103

+5

.300"

209

224

+15

 

 138

138

+7

.400"

247

273

+26

 

 167

 183

 +16

.500"

268

298

+30

 

 188

 206

 +18

.600"

275

311

+36

 

 203

 223

  +20

.700"

278

317

+39

 

 214

 234

 +20

 

Vol: 230 CC                                         76cc              


 


 BB Edelbrock Victor Stage 3 CNC w/  2.200" valve 

                         

440 Port Size
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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 

 

 

 

 

 
 
BB Edelbrock Victor Stage 3 CNC 2.200" Intake valve
                 Max Wedge Port Size 

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 EZ 440 Port Size
with Hughes Super Prep work

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 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
 
 
 
 
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.
 
 
 
 
 
 
 
Magnum or "Iron Ram" style heads
 
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                 
 
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
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" 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 with Hughes Super Prep 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
               

 



    


 
        

 

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