Compare Stock Ports to Various Combinations of "UnderCover Porting"
Compare Stock Ports to Various Combinations of "UnderCover Porting"
How we gathered the flow numbers in this catalog:
The flow numbers are gathered from dozens of tests on each particular head. After we have a wide cross section of tests, the flow figures are averaged to achieve a fair baseline. True, some ports may, on a particular casting, flow 2 to 4 percent more than our average base line. However, the next port (or the next head) may be down more than 4 percent. This is especially true with stock cast iron castings. Also, the head’s flow numbers may change over years, due to changes in production. All of our flow testing is performed at 28” of water with a SuperFlow 600 flow bench, Flow Pro software from Audi Technology and the flow bench equipment displayed in this catalog. |
 |
Vortec Bow-Tie
Stock vs. "UnderCover" Ported
|
Valves: 2.02 x 1.60
Intake Port Volume:
Stock = 185 cc's
"UC" Ported = 190 cc's |
| Lift |
Stock
Intake |
"UC"
Intake |
Stock
Exh. |
"UC"
Exh. |
| .100 |
062 |
064 |
049 |
050 |
| .200 |
128 |
135 |
106 |
110 |
| .300 |
183 |
188 |
134 |
140 |
| .400 |
225 |
232 |
152 |
165 |
| .500 |
235 |
251 |
161 |
179 |
| .600 |
236 |
252 |
163 |
183 |
|
| Bow-Tie Stock vs. "UnderCover" |
Valves: 2.02 x 1.60
Intake Port Volume:
Stock = 171 cc's
"UC" Ported = 176 cc's |
| Lift |
Stock
Intake |
"UC"
Intake |
Stock
Exh. |
"UC"
Exh. |
| .100 |
063 |
068 |
058 |
060 |
| .200 |
126 |
133 |
113 |
118 |
| .300 |
180 |
186 |
135 |
145 |
| .400 |
209 |
224 |
143 |
160 |
| .500 |
212 |
236 |
145 |
168 |
| .600 |
211 |
245 |
147 |
173 |
|
| '062 Vortec Stock vs. "UnderCover" |
Valves: 1.94 x 1.60
Intake Port Volume:
Stock = 165 cc's
"UC" Ported = 170 cc's |
| Lift |
Stock
Intake |
"UC"
Intake |
Stock
Exh. |
"UC"
Exh. |
| .100 |
062 |
063 |
048 |
059 |
| .200 |
128 |
129 |
098 |
117 |
| .300 |
179 |
184 |
127 |
148 |
| .400 |
212 |
221 |
141 |
161 |
| .500 |
216 |
227 |
150 |
170 |
| .600 |
215 |
231 |
156 |
174 |
|
|
’492 Straight Plug Stock vs. "UnderCover"
|
Valves: 2.02 x 1.60
Intake Port Volume:
Stock = 159 cc's
"UC" Ported = 165 cc's |
| Lift |
Stock
Intake |
"UC"
Intake |
Stock
Exh. |
"UC"
Exh. |
| .100 |
64 |
63 |
57 |
60 |
| .200 |
128 |
130 |
107 |
112 |
| .300 |
173 |
184 |
125 |
139 |
| .400 |
195 |
211 |
141 |
158 |
| .500 |
203 |
221 |
141 |
160 |
| .600 |
207 |
224 |
141 |
165 |
|
World Prod. Sportsman II Stock vs. "UnderCover"
|
Valves: 2.02 x 1.60
Intake Port Volume:
Stock = 200 cc's
"UC" Ported = 205 cc's |
| Lift |
Stock
Intake |
"UC"
Intake |
Stock
Exh. |
"UC"
Exh. |
| .100 |
064 |
068 |
060 |
061 |
| .200 |
130 |
139 |
107 |
116 |
| .300 |
186 |
196 |
126 |
146 |
| .400 |
214 |
231 |
139 |
161 |
| .500 |
230 |
245 |
147 |
169 |
| .600 |
233 |
252 |
148 |
174 |
|
|
World Products S/R Stock vs. "UnderCover PLUS Porting"
|
Valves: 2.02 x 1.60
|
| Lift |
Stock
Intake |
"Acid"
Intake |
Stock
Exh. |
"UC"
Exh. |
| .100 |
064 |
068 |
053 |
057 |
| .200 |
130 |
144 |
110 |
108 |
| .300 |
175 |
193 |
126 |
136 |
| .400 |
191 |
211 |
132 |
147 |
| .500 |
196 |
228 |
135 |
154 |
| .600 |
196 |
235 |
135 |
157 |
|
Iron Eagle - 200 cc Non-Platinum Stock vs. "UnderCover"
|
Valves: 2.02 x 1.60
Intake Port Volume:
Stock = 200 cc's
"UC" Ported = 205 cc's |
| Lift |
Stock
Intake |
"UC"
Intake |
Stock
Exh. |
"UC"
Exh. |
| .100 |
068 |
066 |
063 |
061 |
| .200 |
134 |
134 |
115 |
112 |
| .300 |
188 |
186 |
147 |
146 |
| .400 |
226 |
226 |
163 |
170 |
| .500 |
231 |
246 |
168 |
181 |
| .600 |
230 |
253 |
171 |
184 |
| .700 |
228 |
260 |
182 |
190 |
|
Ford 351N Stock vs. "UnderCover"
|
Valves: 2.05 x 1.60
Intake Port Volume:
Stock = 194 cc's
"UC" Ported = 200 cc's |
| Lift |
Stock
Intake |
"UC"
Intake |
Stock
Exh. |
"UC"
Exh. |
| .100 |
060 |
068 |
060 |
061 |
| .200 |
122 |
139 |
107 |
116 |
| .300 |
170 |
196 |
126 |
146 |
| .400 |
208 |
231 |
139 |
161 |
| .500 |
231 |
245 |
147 |
169 |
| .600 |
236 |
259 |
177 |
182 |
| .700 |
236 |
269 |
177 |
199 |
|
Ford 352N Stock vs. "UnderCover"
|
Valves: 2.02 x 1.60
Intake Port Volume:
Stock = 185 cc's
"UC" Ported = 190 cc's |
| Lift |
Stock
Intake |
"UC"
Intake |
Stock
Exh. |
"UC"
Exh. |
| .100 |
065 |
068 |
050 |
055 |
| .200 |
133 |
135 |
097 |
103 |
| .300 |
181 |
184 |
123 |
130 |
| .400 |
210 |
216 |
142 |
155 |
| .500 |
230 |
241 |
153 |
168 |
| .600 |
243 |
257 |
162 |
178 |
| .700 |
248 |
267 |
168 |
184 |
|
Mopar W/2 Stock vs. "UnderCover"
|
Valves: 2.02 x 1.60
|
| Lift |
Stock
Intake |
"UC"
Intake |
Stock
Exh. |
"UC"
Exh. |
| .100 |
063 |
066 |
057 |
056 |
| .200 |
121 |
133 |
105 |
104 |
| .300 |
169 |
182 |
132 |
143 |
| .400 |
211 |
228 |
144 |
167 |
| .500 |
238 |
259 |
148 |
178 |
| .600 |
242 |
269 |
150 |
184 |
|
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