Ive looked countless times for flow numbers on irons but have only came up with people saying how great such and such heads look, and time slips. I want to post up numbers that I personally have tested, I will not post names, not bashing anyone, strictly data. Feel free to add what you have came up with if it is actual data, not what your car ran in the 1/4. This is strictly for FUN, and can be competitive for some!
One thing I did notice on all the testing was the heads all became turbulent around .450-.500 lift. Just an observation.
Below are numbers I tested off a superflow 300 bench, 69 degrees in the shop at the time, at sea level.
First up, stock 8445 heads, stock valves, absolutely NO work untouched heads. This is the intake
Flow conducted at 25" water at .050 lift increments.
.050 29
100 55
150 80
200 100
250 126
300 136
350 142
400 144
450 148
500 150
Around .500 lift the head dies out and gained nothing. Results may vary but that is what I got.
Next is a stock intake port with a back cut valve. The port actually performed poor with just a valve cut.
Stock intake port, back cut valve 25" water:
.050 24
100 52
150 81
200 102
250 122
300 136
350 142
400 144
450 145
500 146
Next up is my personal stock ported head. Very minimal work in the bowl and short side radius with a back cut valve. I do not remember what we cut the valve at, will post that info later. This was about 1hr of work. Keep in mind these flow numbers are at 25" water. Add roughly 6% if you want to compare to an industry flowed head.
Stock intake, minimal hand porting, back cut valve @25" water:
L %
.050. 29
100 58
150 88
200 112
250 138
300 152
350 154
400 156
450 159
500 160
Between .450-.500" lift head has not more to gain.
Next up is another example of a hand ported head. This was by a professional and looks pretty good. Stock intake valve with a valve job, hand ported, polished chamber, very minimal material taken from runners and valve boss. Looks to be mostly bowl work. These were tested at 28" of water by request as it was tested next to an industry supplied iron head.
.050 32
100 57.5
150 86
200 106
300 137
400 166
500 176
Thought I took a pic of intake runners. Will post a pic tonight.
Next up is another professionally ported iron head. 1.775" intake valve, combustion chamber has been re shaped to unshroud the valves, tested at 28" water.
.050 27
100 57
150 91
200 118
250 148
300 170
350 182
400 182
450 184
500 185
I would LOVE to see pics of an iron head that outflows the last head I posted and data. I'm chasing the dragon right now with this head porting and all the info I can get the better.
UPDATED 1/11/16
Did some more porting and testing today. Still working with a stock back cut intake valve, VERY minimal material work in the intake runner, just enough to remove the casting bumps.
Test done at 25" water, stock intake valve w/ back cut.
.050 30
.100 58
.150 81.5
.200 104
.250 124
.300 144
.350 160
.400 165
.450 169
.500 173
.500 183 @ 28" water! Thats good progress, i'm pretty happy about it.
I picked up 13 cfm today doing bowl work. Pretty interesting that most of this work is in the bowl. I also took a little off the chamber to unshroud the intake valve, I'll post pics next week if I finish the port.
One thing I did notice on all the testing was the heads all became turbulent around .450-.500 lift. Just an observation.
Below are numbers I tested off a superflow 300 bench, 69 degrees in the shop at the time, at sea level.
First up, stock 8445 heads, stock valves, absolutely NO work untouched heads. This is the intake
Flow conducted at 25" water at .050 lift increments.
.050 29
100 55
150 80
200 100
250 126
300 136
350 142
400 144
450 148
500 150
Around .500 lift the head dies out and gained nothing. Results may vary but that is what I got.
Next is a stock intake port with a back cut valve. The port actually performed poor with just a valve cut.
Stock intake port, back cut valve 25" water:
.050 24
100 52
150 81
200 102
250 122
300 136
350 142
400 144
450 145
500 146
Next up is my personal stock ported head. Very minimal work in the bowl and short side radius with a back cut valve. I do not remember what we cut the valve at, will post that info later. This was about 1hr of work. Keep in mind these flow numbers are at 25" water. Add roughly 6% if you want to compare to an industry flowed head.
Stock intake, minimal hand porting, back cut valve @25" water:
L %
.050. 29
100 58
150 88
200 112
250 138
300 152
350 154
400 156
450 159
500 160
Between .450-.500" lift head has not more to gain.
Next up is another example of a hand ported head. This was by a professional and looks pretty good. Stock intake valve with a valve job, hand ported, polished chamber, very minimal material taken from runners and valve boss. Looks to be mostly bowl work. These were tested at 28" of water by request as it was tested next to an industry supplied iron head.
.050 32
100 57.5
150 86
200 106
300 137
400 166
500 176
Thought I took a pic of intake runners. Will post a pic tonight.
Next up is another professionally ported iron head. 1.775" intake valve, combustion chamber has been re shaped to unshroud the valves, tested at 28" water.
.050 27
100 57
150 91
200 118
250 148
300 170
350 182
400 182
450 184
500 185
I would LOVE to see pics of an iron head that outflows the last head I posted and data. I'm chasing the dragon right now with this head porting and all the info I can get the better.
UPDATED 1/11/16
Did some more porting and testing today. Still working with a stock back cut intake valve, VERY minimal material work in the intake runner, just enough to remove the casting bumps.
Test done at 25" water, stock intake valve w/ back cut.
.050 30
.100 58
.150 81.5
.200 104
.250 124
.300 144
.350 160
.400 165
.450 169
.500 173
.500 183 @ 28" water! Thats good progress, i'm pretty happy about it.
I picked up 13 cfm today doing bowl work. Pretty interesting that most of this work is in the bowl. I also took a little off the chamber to unshroud the intake valve, I'll post pics next week if I finish the port.
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