804
KB
PERFORMANCE PISTONS
Note: It is important to use our ring end gap instructions to avoid ring
butting.
Safe top ring end gaps can be found by multiplying the bore diameter
by the appropriate ring end gap factor from the adjoining chart.
Example: 3.5" bore Street Normally Aspirated" = 3.5" bore x .0065" =
.023" top ring end gap.
Note: Second ring end gaps do not need extra clearance.
The Keith Black 390 Hypereutectic alloy is cast in a permanent steel
mold which makes it possible to build a light weight piston that makes
more power, runs quietly, uses less fuel and lasts longer than any other
type of piston being made today. We can now forget about running
loose, noisy, oil-burning pistons. The low heat transfer of the alloy keeps
the skirts cool so piston expansion is minimal.
The KB piston will make maximum power at 2 to 4 degrees less total
timing than conventional pistons. All KB pistons sets are supplied with
Hastings Moly Ring sets.
Engine
1000cc 1200cc
1200cc 883 to1200cc
Sportster Evolution Evolution Conversion
Model
XLH-XLCH XL
XL 1 9 8 8 -u p X L
Years
1972-85 1988-up w/High Cams 1986-up
C.I.D.
61"
74"
74"
74"
Bore
3.188" 3.498" 3.498"
3.498"
Stroke
3.812" 3.812" 3.812"
3.812"
Head Type Dome Flat Top Flat Top
Dish
Cyl Height 5.330" 4.650" 4.650
4.650"
Comp. Ratio 9.0:1
9.0:1
9.0:1
9.0:1
STD
.005
.010
.020
.030
.040
RING END
PISTON TO WALL
APPLICATION
GAP FACTOR
CLEARANCE
Street Normally Aspirated
.0065"
.00075"-.0015"
Street Nitrous or Supercharged
.0080"
.0015"-.0025"
Flat Track Gasoline.0080"
.0010"-.0030"
Flat Track Alcohol
.0060"
.0010"-.0030"
Drag Gasoline
.0075"
.0010"-.0030"
Drag Alcohol
.0065"
.0010"-.0030"
Drag Supercharged or Nitrous Gas .0095"
.0015"-.0030"
Drag Supercharged Alcohol
.0085"
.0010"-.0030"
Drag Supercharged Fuel
.0115"
.0020"-.0040
"
V-Twin Piston Kits include 2 Cast Alloy Pistons, Genuine Hastings 3-Piece
Ring Set, 2 Wrist Pins and 4 Circlips.
V-Twin Piston Kits
Piston Sets use 22588-78 Pin Lock, VT No. 12-0929
COMP STD 9:1 STD 9:1
LC 8.4:1
STD
STD
STD
900cc XL 1000cc XL 1000cc XL 883cu V2 1100cc V2 1200cc V2
Dia. 3" Bore
3
3
/
1 6
" Bore 3
3
/
1 6
" Bore Evolution Evolution Evolution
STD
.005
.010
.020
.030
.040
.050
.060
.070
Wrist Pin and Lock Kit.
VT No. OEM
Year/Model
Wrist Pin Locks, 10 packs.
Over 100,000 Kits Sold Since 1978!
