Been tied up with weight reduction activities on the car for the past couple years, and finally getting back to working on the engine (swapping out the intake manifold). The present antique C396 manifold I'm using (for the stock/sleeper look) has a divided plenum, but I've got a second similar manifold that I cut down the plenum divider height. (I'm also currently working on cutting out the under-manifold exhaust crossover casting material to take another bit of weight off the top of the engine.) Once I get the manifold swapped I'll need to play with the jetting, of course, but I'd like to be a bit more familiar with the actual physics of why BBCs need this stagger jetting when used with an open plenum. I'm familiar with the unequal port lengths in the heads, but what exactly is happening there that requires the stagger jetting "bandaid"? And given that I only have one WBO2 sensor installed at a time on the exhaust, I'm trying to make sure I can make sense of the average A/F readings that the sensor is reading.
All I've ever seen in any manual or carb book is a recommendation to change the jet sizes on the cross locations, but not any actual reason why. Any constructive information I can use from the collective would be appreciated.
Thanks.
All I've ever seen in any manual or carb book is a recommendation to change the jet sizes on the cross locations, but not any actual reason why. Any constructive information I can use from the collective would be appreciated.
Thanks.
