* Oil leaks: Excessive pressure can force oil past seals and gaskets, leading to leaks.
* Damage to seals and gaskets: Constant pressure can prematurely wear out seals and gaskets.
* Engine damage: Extreme pressure buildup can damage internal engine components.
* Blowby: Excessive blowby (pressure from combustion leaking past the pistons) will increase, leading to more contaminants in the crankcase oil.
The method of ventilation can vary:
* PCV (Positive Crankcase Ventilation) system: This is the most common and recommended method. It uses a PCV valve to regulate crankcase pressure and route blowby gases back into the intake manifold for combustion. This is generally preferred for its emissions control benefits.
* Road draft ventilation: Older engines sometimes used a simple vent tube routed to the atmosphere. This is less efficient and not environmentally friendly due to unfiltered fumes escaping the engine. It's generally not recommended for modern applications.
* Breather cap/filter: Some setups might use a breather cap or filter on one valve cover, and route the other to the intake. This can be simpler than a full PCV system, but still helps control pressure.
In short, while the *specific* method can vary, proper crankcase ventilation is essential for the long-term health and proper operation of your 350 Chevy. Not venting them is a recipe for disaster.
