1986 to 1999 Evo Sportster Specs

evolution sportster specifications

Some specifications for 883, 1100 and 1200 Evolution Sportsters, 1986 to 1999

  • Bore 883std. 3.00″   .010os 3.010″   .020os  3.020″
  • Bore 1100:  std.   3.350″
  • Bore 1200:  std. 3.498″  .010os 3.508″  .020os 3.518″
  • Stroke:  3.812″  (3 13/16″)
  • Connecting Rod Length: 6.926″

Keith Black Forged Pistons

keith black pistons for evolution engines

When building a high performance engine you want to use the very best. Keith Black Forged Pistons are an excellent choice. KB Performance pistons are a Forged 4032 low expansion alloy. The 4032 alloy is preferred for high performance / high compression applications. They offer offset wrist pins for a quiet running engine. The low expansion alloy allows for a tighter piston to wall running clearance which lets the piston rings do their job better. This means better compression with less blow-by and better oil control to keep oil out of the combustion chamber. The cleaner the charge, the better it burns, the more power you have. :?)