Related Clues:
- Engine option
- 50 percent (prefix)
- Prefix with "sphere"
- Prefix meaning "half"
- Fractional prefix
- It means ''half''
- Half prefix
- Auto engine nickname based on its shape, briefly
- Sphere lead-in
- Prefix with -trope
- Engine with dome-shaped combustion chambers
- High-end car engine
- Hot-rod engine, briefly
- 50%, up front?
- Prefix with ''sphere''