S&S Cycle Sidewinder 3 5/8 Big Bore Cylinders for 1936–1999 Big Twins - Manual (Page 15)

15
G. Measure width of female rod on crankpin end. See Picture 10, above left. Measurement should be 1.743” to 1.745”.
H. Assemble left and right flywheels and moderately snug nuts. Do not worry about them being true. Measure distance between connecting
rod thrust pads. See Picture 11, above right.
NOTE: S&S recommended rod side play is .015" to .035". Rod Side Play = (Distance from Pad to Pad) - (Female Rod Width)
Incorrect connecting rod side play may cause excessive rod side thrusting and potential damage to rods, flywheels and other engine
components.
If difference is less than .020", female rod must be ground on sides as final tightening will pull wheels closer together. Rod side play diminishes
about .015" when crankpin nut is final tightened. Take equal amounts off each side if amount to be removed is more than .010". If there is no rod
side play try different crankpin. If rod side play is more than .035", try different crankpin. We have run side play of as much as .045" without serious
consequences. If side play is excessive and different crankpins do not correct problem, contact your S&S Tech representative.
NOTE: If material is removed from sides of female rod, overall width of bearing cages must be reduced so bearings and cages are free to float with rods
without contacting flywheel thrust pads. Bearing cage side clearance of .008 to .020 less than rod width is recommended.
Connecting rod bearing and cage assemblies that are wider than female rod may become damaged upon contact with flywheel thrust
pads. Damaged rod bearing assemblies and/or foreign material from damaged components circulating in oil could cause further
destruction and possible failure of other engine parts.
I. Finish assembling flywheels and rods. Flywheel assemblies machined for stock 1972 to early 1981 sprocket shaft may be more difficult to
true because of the 81⁄2° sprocket shaft taper. Following above procedures will help diagnose problem if difficulty should arise.
12. Connecting Rod Alignment (All)
After flywheel assembly is installed in crankcases, rods must be checked for straightness.
NOTES:
• The purpose of this procedure is to correct for machining tolerance discrepancies in components which may lead to pistons not running true in
cylinder bores. While rods may be straight and true, it is sometimes necessary, to bend them to correct for these machining discrepancies. Do not
bend rod by using tool in wristpin hole as this method may distort wristpin bushing. We also feel that using a piston in lieu of a checking pin may
prove inaccurate due to variations in lengths of piston skirts from one side of piston to the other.
• All engines should be checked upon disassembly for incorrect piston alignment. This applies to those which are receiving new pistons as well as
those being completely rebuilt. Observe pistons for wear spots on sides above top compression ring. If one side near wristpin is worn clean while
side opposite is carboned up, then piston was not running straight and true in cylinder bore. Piston will also generally show diagonal wear pattern
on thrust faces of skirts and possibly signs of connecting rod to wristpin boss contact inside piston.
• We feel that not enough emphasis is given to checking piston alignment in cylinder bore. Proper piston alignment means connecting rods will
thrust to sides less minimizing added stress on pistons, rings, rod bearings and other related parts.
• S&S® Rod Checking Pin, Part #53-0002, was designed to help perform this procedure. It may also be necessary, to fabricate a rod bending tool as
illustrated in Figure 5, next page.
CAUTION
CAUTION
Picture 10 Picture 11