The classic D-series engine had to be on the list for CNC baffle services! Although not as common as K-series covers, we still see these come through the shop and much like the B-series non-VTEC covers, they're very difficult to clean. The chambers are very restrictive and have multiple areas that make it next to impossible to flush without removing the baffle. With these covers being so old and neglected, you shouldn't be surprised with what you find, but we always are. Take a look...
There are two variations of the D-series baffling; the Z6 (5th gen) and the Y8 (6th gen). They're virtually identical in overall shape, but the rivet locations are different from one baffle to the other. The baffles are completely flat which allowed us to easily cut a brand new baffle and finish it off with zinc coating. While the baffle chambers were exposed, we took some time to understand the inner workings which resulted in making some modifications to the chambers and baffle itself.Â
Â
There are a few entry points for crankcase pressure, but the main one is on the far right (in the photo below). When the baffle is removed, you can easily trace the pathway crankcase pressure follows. As crankcase pressure passes through the main entry point of the baffle and into the chamber, it makes its way across the valve cover past the other two small entry points. Once it reaches the end of that chamber, there's a tiny passage where crankcase pressure has to flow through in order to flow back across the length of the valve cover to reach the vent at the far corner.Â
We identified that this small passage was quite the restriction in airflow so we decided to open up another passage on the opposite end, near the main entry point. In addition to that, we modified the entry points on the baffle by opening them up significantly.
Â
This cover ended up requiring quite a bit of work, but we're happy with the outcome! The baffle service is now standard when getting your cover coated and the baffle service is also available on its own.Â
- CNC baffle extraction - drilled and tapped
- De-gasket baffle mating surfaces
- Entire cover media blasted, hot tanked, and cleaned
- Laser cut custom zinc plated baffle with enlarged entry ways
- Stainless inverted Torx (T25) head hardware
- Modified baffle walls for increased flow
- Powder coated in the color of your choosing
