S&S Cycle Sidewinder 3 5/8 Big Bore Cylinders for 1936–1999 Big Twins - Manual (Page 24)

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S&S Sidewinder Piston Information
Failure to follow instructions and perform required clearancing, installation and/or break-in procedures correctly may result in damage
to pistons and/or other engine components. S&S® voids its guarantee if pistons are not installed and/or broken in properly.
1. For maximum piston and ring life, fit pistons using appropriate close fit dimensions. Close fit requires absolute adherence to new engine
break-in as outlined.
2. For immediate drag strip use, fit pistons using loose fit dimensions. Attempt to break in rings and pistons with 50 easy miles if possible. Piston
and ring life will be reduced when using loose fit dimensions.
3. Measure all pistons across thrust faces 90˚ to wristpin holes. Make a series of measurements starting directly below oil ring groove and ending
at extreme bottom of skirt. Use widest measurement to represent size of piston. Some pistons will measure widest at extreme bottom of
skirt. Others will measure widest somewhere between oil ring groove and extreme bottom of skirt. If piston is notched for placement in rear
cylinder, use measurement directly above notch as extreme bottom of skirt measurement.
4. S&S recommends the use of #220–#280 grit stone for final honing of cylinders for all Sidewinder® big bore engines.
5. Follow procedure recommended in Harley-Davidson® service manual for boring and honing cylinders. S&S Cylinder Torque Plate Kit, S&S Part
#53-0016, or Harley-Davidson® torque plates, H-D® Part #33446, are required when fitting cylinders for Evolution® engines to simulate engine
operating conditions. Cylinders may distort more than .001" if torque plates are not used.
All reference to Harley-Davidson® part numbers is for identification purposes only. We in no way are implying that any of S&S® Cycle’s products are
original equipment parts or that they are equivalent to the corresponding Harley-Davidson® part number shown.
Piston Installation
1. All currently supplied pistons are forged and do not have offset wristpins. They have no special features and can be installed any way the
builder desires except for the rear piston which has a piston to piston clearance notch on front skirt thrust face of the piston. Install rear piston
with notch toward front piston.
2. Check all installations for a minimum of .060" clearance between pistons at bottom of stroke.
3. Check all installations for a minimum of .060" clearance between pistons and flywheels at bottom of stroke. New 45⁄8” Sidewinder installations
should come with proper piston to flywheel clearance. Replacement pistons may or may not come with adequate clearance. Compare
replacement pistons with ones being replaced and make corrections accordingly.
Wristpin Retainer Installation
1. All pistons use round wire wristpin retainers. Make sure retainer groove is free of burrs and foreign material.
2. Round wire style clips which are identical to and interchangeable with stock clips for Harley-Davidson® Evolution® engines require a specially
chamfered end wristpin. Install clips using factory recommended procedure. Special indexing of clip is not necessary. Be sure clip is fully
seated in groove.
Part Number Description Part # Stamped on Piston Close Fit Loose Fit Old S&S® PNs That Are Superceded
106-5535
Piston Set 35/8" Standard, HC,
.791" WP, 1936–''84 bt
106-5531 .0035" to .004" .0045" to .0055" 92-1800 92-1830 92-1840 92-1620 92-1630 92-1640
106-5536
Piston Set 35/8" +.010", HC, .791"
WP, 1936–'84 bt
106-5532 .0035" to .004" .0045" to .0055" 92-1801 92-1831 92-1841 92-1621 92-1631 92-1641
106-5537
Piston Set 35/8" +.020", HC, .791"
WP, 1936–'84 bt
106-5533 .0035" to .004" .0045" to .0055" 92-1802 92-1832 92-1842 92-1622 92-1632 92-1642
106-5538
Piston Set 35/8" +.030", HC, .791"
WP, 1936–'84 bt
106-5534 .0035" to .004" .0045" to .0055" 92-1803 92-1833 92-1843 92-1623 92-1633 92-1643
106-5789
Piston Set 35/8" +.060", HC, .791"
WP, 1936–'84 bt
106-5790 .0035" to .004" .0045" to .0055" 92-1806 92-1836 92-1846 92-1626 92-1636 92-1646
92-1900 Series Piston Set 35/8", flat top .792" WP,
1984–'99 bt
92-1900 to 92-1906 .002" to .0025" .003" to .004" - - - - - -
92-1930 Series Piston Set 35/8", flat top .792" WP,
1984–'99 bt
92-1930 to 92-1936 .002" to .0025" .003" to .004" - - - - - -
92-1940 Series Piston Set 35/8", flat top .792" WP,
1984–'99 bt and 1986–’03 xl
92-1940 to 92-1946 .002" to .0025" .003" to .004" - - - - - -
CAUTION