| Intake porting guide |
| Step 5 Open passage from flange inward to back of pushrod pinch on left side of passage |
| pg-4 |
| The passage doesn't need to be made appreciably larger. Opening the pushrod pinch on the left side helps when the larger intake valve size is used. When shaped correctly this size passage will flow 350 cfm. This is more than adequate for most hot street builds under 600 hp. |
| Although polishing the passage makes it "pretty" it isn't necessary. Some final sanding with a 120 grit sanding drum or cartridge roll will smooth the surface and help you to see any low spots or surface irregualrities. Some surface roughness will help to keep fuel in suspension. Especially on the passage floor. |
| D0VE style intakes ported according to this guide will flow about 300 to 340 cfm at .6" to .7" lift. This is enough air flow to support 600 hp in a max effort application. |
| One minor issue with the passanger car intake ports is the shape of the floor at the flange. The floor is low and has a bell mouth right near the flange from 12:00 o'clock to about 7:00 o'clock. One sure way to alleviate this is to port match to the CJ intake gasket ( felpro # 1231) This shapes the passage kind of like a funnel and helps flow potential appreciably. You must use a CJ port intake manifold. Flow with a manifold attached is enhanced when the first 3/4" of the port left and right sides both, is perpendicular to the flange. If the intake manifold runner size at the flange is smaller than that first 3/4'' of the intake port this is ok. Do not open the manifold runner exit to the port entry size. This WILL hurt flow at high velocities.This is especially an issue when manifold runner cross section is smaller before the flange. The whole intake tract must be taken into consideration when modifications are being made. |
| Do not open the whole passage up to the CJ size. Open the first 3/4" and taper into the passage. Making the passage a bit larger is good, say .100" or so. Pay close attention to the areas adjacent to the push rod tunnels. Use care so as to not break through. |
95
163
223
268
301
325
342
355
163
223
268
301
325
342
355
| The cross sectional area of this port is near CJ size as it is now. The bath tub shape appears to be more efficient from a velocity standpoint. And remember that these ports flow better when the first 3/4" of the passange is straight off the flange or 90 degrees to the flange. 12-02, SMJ/RHP |
| A maximized D0VE-C intake port with the CJ match and straight entry treatment will flow near 390 cfm on a bench and in excess of 300 cfm with a CJ port stealth with an 850 holley DP. 600+ hp no problem !!! A proper CJ match is alot of work though so be prepared. |
| Pic courtesy of Rick at automated inc. |
| CJ--PI--STD |
