When leaving the primary port near stock shape (just cleaning up the rough casting), does porting the secondary ports have any effect on emissions? The secondary throttle plates should be close to closed (only slightly open via the throttle stop screw)at idle positions, and the secondary injectors are offline.

If you were to completely close the secondary runners, (say by blocking off the intake runners), would the primary ports be the only ports affecting emissions?

 

no response to this? Whether a secondary only ported engine will have any affect on emissions when there is no flow to them? I am only curious about air/fuel flowing into the block-off secondaries, but I can't really see that occuring since the air/fuel will be under vacuum at that point.

The only problem I am seeing right now is setting the idle as the secondary throttle stop screw will not affect anything, so I will have to set idle completely based upon the BAC Valve and setting then finding a way to set the primary throttle, probably through cable tension.

 

bump, I would also like to hear some information.

 

It will pass