Speed & Science Billet Aluminium Heads, 3-5/8" Big Bore, Bare, Shovelhead

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Speed & Science Billet Aluminium Heads, Shovelhead
- 3-5/8" Big Bore
- Bare Version ( w/o valves, valve guides, valve springs, seats )
- includes CNC machines Manifold for S&S Super E
- all new developed Billet Aluminium Cylinder Heads by Speed & Science, Canada
- CNC machined from 6061-T6 Aluminium
- all new developed port and chamber geometry for respectable HP gains while still maintaining good engine lifetimes
- calculated compression ratio with 3-5/8" Big Bore Pistons: 10.05:1 with 4-1/4" Stroke (10.55:1 w. 4-1/2" and 10.80:1 with 4-5/8" Stroke)
- Hi-tensile steel thread inserts (headbolts, intake, exhaust) installed; all original thread sizes, no need for “special” fasteners
- Increased cooling area drops the head’s operating temperature up to 35F
- completely redesigned Intake <–> Head interface, thus eliminating vacuum leaks
- OEM oil drain location