Related Clues:
- It means ''half''
- Prefix meaning ''air''
- Half prefix
- Auto engine nickname based on its shape, briefly
- Type of internal-combustion engine
- Prefix with -trope
- Engine with dome-shaped combustion chambers
- High-end car engine
- Hot-rod engine, briefly
- 50%, up front?
- Prefix with ''sphere''
- Vapor, in combinations
- It means half
- Prefix with 'sphere'
- Fifty percent, up front?