S&S CYCLE S&S® Super Stock® 89cc Cylinder Head Kit For 1999-'05 HD® Big Twins - Silver Powder Coat Finish 106-4270

These S&S^® Super Stock^® high performance cylinder heads are designed for 1999-'05 engines with stock crankcase. They work well with engines of stock displacement, but are ideal for somewhat larger stroker or big bore engines up to 110". The 89cc combustion chamber provides a slightly higher than stock, but still manageable compression ratio in larger than stock engines. This makes them a good choice for touring bikes and other heavy vehicles. The large 2.000" intake and 1.605" exhaust valves maintain port velecity for good low and midrange response, but supply enough air for slightly larger engines to perform to their full potential. S&S^® High performance valve springs allow the installation of camshafts with up to .650" lift. Intake ports flow 264 cfm compared to stock heads at 182cfm. S&S^® High performance valve springs allow the installation of camshafts with up to .650" lift. Compatible with stock rocker boxes, exhaust, and intake manifolds. Silver powder coat finish matches stock silver engine components.

• High port flow gives great performance now, and more later when additional upgrades are done
• Heads are fully assembled with springs and valves
• Compression ratios vary depending on cylinder heads chosen, pistons used and engine displacement; see Compression Ratios chart for specifications
• 79cc heads work great with stock motors for 88" to 103" motors; 89cc heads work best for motors over 103" or with high-compression pop-up pistons
• 79cc have 1.940" intake and 1.575" exhaust valve and springs for up to .640" lift; 89cc have 2.000" intake and 1.605" exhaust and .640" springs
• Heads are machined for compression releases unless noted otherwise (sold separately); S&S rocker boxes required when using S&S compression releases
• Do not include rocker arm components, intake manifold or gaskets
• Heads include four long headbolts, and reuse four long OEM headbolts
• Accept OEM intake manifolds
• Made in the U.S.A.
• Must use S&S rocker boxes (PART #90-4110) if S&S compression releases are used.
• Not compatible with Twin Cooled heads.
  
  NOTE: Accept OE rocker boxes
  
  

Fitment Guide

Specs