S&S Cycle Sidewinder 3 5/8 Big Bore Cylinders for 1936–1999 Big Twins - Manual (Page 19)

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Head Gasket Surface Flatness Check
Before top end is assembled, head gasket to cylinder mating surfaces should be checked.
Incomplete contact between gasket surfaces of cylinders and cylinder heads may cause combustion leakage possibly resulting in
damage to cylinders and/or other engine components.
Perform following steps for panhead and/or shovelhead
A. Thoroughly clean head and cylinder gasket surfaces.
B. Apply valve grinding compound to surface and lap head to cylinder.
C. If brief lapping reveals that surfaces are not fully contacting each other, machine head gasket surface just enough to make complete
contact.
NOTE: If head gasket surface on cylinder head is machined, be sure that depth of recess equals height of fire ring, or head gasket may not seal. If more
than .010" material is removed from head gasket surface, recheck piston to head and piston to valve clearances.
Incorrect cylinder fire ring recess depth machined in cylinder heads may cause combustion leakage possibly resulting in damage to
cylinders and/or other engine components.
D. Thoroughly clean all lapping compound from heads and cylinders before assembling.
Lapping compound is highly abrasive and may damage engine components if allowed to circulate in engine oil.
Perform followings steps for knucklehead and Harley-Davidson® Evolution® engines:
A. Thoroughly clean head and cylinder gasket surfaces.
B. Place straight edge ruler across head gasket surface at different places around diameter to determine flatness.
C. If unevenness is revealed, machine head gasket surface just enough to make complete contact.
Final Top End Assembly
NOTES:
• We have good luck assembling base gaskets clean and dry. If you wish to use gasket cement we recommend using a ‘‘drying” type such as “Copper
Coat” as “non-drying” type will occasionally allow gasket to squeeze out of position.
• We prefer to install head gaskets dry also. If you prefer, you can use a gasket sealer such as “Copper Coat.”
Knucklehead, panhead, and shovelhead Top End Assembly Procedure
NOTE: We recommend installing cylinders without heads bolted to cylinders for two reasons.
1. Combined weight of cylinder and cylinder head makes assembly cumbersome and hard to handle during installation.
2. Separate installation of cylinders and cylinder heads permits more leeway for adjustment to achieve a better manifold fit.
Installation of cylinders and cylinder heads as assemblies may result in damage to rings and piston assemblies. Improper intake
manifold fit may cause intake air leaks/improper fuel mixture and resultant damage to engine components.
CAUTION
CAUTION
CAUTION
CAUTION