Date cc Model Note Metal Cyl Bore (mm) Cyl Bore (in) Ref No. Veloce Part No. Comp Length Bottom Skirt Diameter Clearance - Inch Weight Head No.Rings Top Width Ref.No or Radial Depth Second Width Ref.No or Radial Depth Third / Oil RingWidth Ref.No or Radial Depth Ring Below Pin Width Ref Pin Dia Pin Length Type Pin Ref No.
1928/9 249 U Offset inlet port 1 on Circumference at bottom of skirt   Cast Iron 63.00 2.4803 8112   1 19/32 3 27/32       Two Stroke 2 1/8 0.091" 1/8 0.091" * * * *     GP.8112
1929 249 USS 48mm Offset Port 48mm at Bottom of Skirt   Al 63.00 2.4803 3871   1 25/32 4 1/32       Two Stroke 2 3/32 0.091" 3/32 0.091" * * * *     GP.3871
1930/1 249 GTP inlet port 1 5/16 on circumference at bottom of skirt   Al 63.00 2.4803 3867   1 4       Two Stroke 2 1/8 0.091" 1/8 0.091" * * * *     GP.3867
1930/3 249 GTP inlet port 1 on circumference at bottom of skirt   Al 63.00 2.4803 3868   1 4       Two Stroke 2 1/8 0.091" 1/8 0.091" * * * *     GP.3868
1934/40 249 GTP inlet port 1 1/16 on circumference in middle of skirt   Al 63.00 2.4803 WP.1520   1 25/32 4 1/32       Two stroke 2 3/32 0.091" 3/32 0.091" * * * *     127E.11
1932/3 249 GTP inlet port 1 5/16 on circumference at bottom of skirt   Al 63.00 2.4803 3869   1 25/32 4 1/32       Two stroke 2 3/32 0.091" 3/32 0.091" * * * *     GP.3869
  249 GTP offset inlet port 1 on circumference at bottom of skirt   Al 63.00 2.4803 3872   1 25/32 4 1/32       Two Stroke 2 3/32 0.091" 3/32 0.091" * * * *     GP.3872
  249 GTP inlet port 1 13/16 on circumference in middle of skirt   Al 63.00 2.4803 3873   1 25/32 4 1/32       Two stroke 2 3/32 0.091" 3/32 0.091" * * * *     GP.3873
  249 GTP   Al 63.00 2.4803 3870   1 25/32 4 1/32       Two stroke 2 3/32 0.091" 3/32 0.091" * * * *     GP.3870
1934/49 248 OHV MOV /MAC Slipper Design Al 68.00 2.6772 WP.357   1 9/16 3       Dome (with valve pockets) 3 1/16 0.098" 1/16 0.098" 5/32" 0.098" * * 5/8     158E.38
6.0 to 1         * *
1956 349 OHV Viper (Split skirt Alfin barrel) superseded by 2301-5 Al (52) 72.00 2.8346 2301-4 M27-13 2.437 3.408 2.8347 0.000   Dome (with valve pockets) 3 0.0625 0.115" 0.0625 0.115" 0.1575 0.115" * * .8226     2.09E+05
1956 349 OHV Viper (Split skirt Alfin barrel) Al (52) 72.00 2.8346 2301-5 M27-13 2.437 3.408 2.8337 0.001   Dome (with valve pockets) 3 0.0625 0.115" 0.0625 0.115" 0.1575 0.115" * * .8226     2.09E+05
  349 OHV Viper Scrambles (Solid skirt Alfin barrel) superseded by 2301-? Al (52) 72.00 2.8346 2310-3 M27-17 2.437 3.408 2.8335 0.001   Dome (with valve pockets) 3 0.0625 0.115" 0.0625 0.115" 0.1575 0.115" * * .8226     2.09E+05
  349 OHV Viper Scrambles (Solid skirt Alfin barrel) Al (52) 72.00 2.8346 2310-? M27-17 2.437 3.408 2.8315 0.003   Dome (with valve pockets) 3 0.0625 0.115" 0.0625 0.115" 0.1575 0.115" * * .8226     2.09E+05
1960 349 OHV Viper (Split skirt Iron barrel) Superseded by 2310-10 Al (52) 72.00 2.8346 2310-8 M27-27 2.437 3.408 2.8327 0.002   Dome (with valve pockets) 3 0.0625 0.115" 0.0625 0.115" 0.1575 0.115" * * .8226     2.09E+05
1960 349 OHV Viper (Split skirt Iron barrel) Al (52) 72.00 2.8346 2310-10 M27-27 2.437 3.408 2.8315 0.003   Dome (with valve pockets) 3 0.0625 0.115" 0.0625 0.115" 0.1575 0.115" * * .8226     2.09E+05
1960 349 OHV Viper / Scrambles (solid skirt Iron barrel) Al (52) 72.00 2.8346 2310-9 M27- 24 2.437 3.408 2.8305 0.004   Dome (with valve pockets) 3 0.0625 0.115" 0.0625 0.115" 0.1575 0.115" * * .8226     2.09E+05
  348 OHC   Al 74.00 2.9134 3885   1 19/32 2 29/32       Dome 3 1/8 0.105" 1/8" 0.105" 5/32" 0.105" * * 0.8236     GP.3885
  348 OHC KTT CR 11.5 to 1 Al 74.00 2.9134 3883   2 3/32 3 7/16       Dome 3 1/16 0.106" 1/16 0.106" 5/32" 0.106" * * 0.8236     GP3883
  348 OHC   Al 74.00 2.9134 3884   1 3/4 3 1/16       Flat Bevelled 3 1/8 0.105" 1/8" 0.105" 5/32" 0.105" * * 5/8     GP.3884
  348 OHC   Al 74.00 2.9134 3888   1 7/8 3 3/16       Dome 2 1/16 0.105" 1/16 0.105"   0.105" * * 5/8     GP3888
  348 OHC   Al 74.00 2.9134 3887   1 31/32 3 9/32       Dome 3 1/16 0.105" 1/16 0.105" 5/32" 0.105" * * 5/8     GP3887
  348 OHC   Al 74.00 2.9134 3886   1 13/16 3 1/8       Cone 3 1/16 0.105" 1/16 0.105" 5/32" 0.105" * * 5/8     GP3886
1929 348 OHC KTT CR 7 to 1 Al 74.00 2.9134 3875   1 27/32 3 7/32       Dome 3 1/16 0.106" 1/16 0.106" 5/32" 0.106" * * 0.8236     GP.3875
1929 348 OHC KTT CR 8.5 to 1 Al 74.00 2.9134 3876   1 27/32 3 5/32       Dome 3 1/16 0.106" 1/16 0.106" 1/16 0.106" * * 0.8236     GP.3876
1929/30 348 OHC KTS, KSS 10.25 to 1 Al 74.00 2.9134 3877   2 1/8 3 7/32       Cone 3 1/16 0.105" 1/16 0.105" 1/16 0.105" * * 5/8     GP.3877
1929/31 348 OHC KTP, KN Al 74.00 2.9134 3878   1 25/32 3 3/32       Cone Stepped 3 1/8 0.105" 1/8" 0.105" 5/32" 0.105" * * 5/8     GP.3878
1929/31 348 OHC KTT CR 10.25 to 1 Al 74.00 2.9134 3879   1 31/32 3 9/32       Cone 3 1/16 0.106" 1/16 0.106" 1/16 0.106" * * 0.8236     GP3879
1932/35 348 OHC KTS 6.5 to 1 Al 74.00 2.9134 3881   1 3/4 3 3/32       Dome 3 1/16 0.105" 1/16 0.105" 5/32" 0.105" * * 5/8     GP.3881
1933 348 OHC KTT CR 7.75 to 1 Al 74.00 2.9134 3880   1 25/32 3 5/32       Dome 3 1/16 0.106" 1/16 0.106" 5/32" 0.106" * * 0.8236     GP.3880
1936 348 OHC KTS 6.8 to 1 Slipper Design Al 74.00 2.9134 3882   1 13/16 3 1/8       Dome 3 1/16 0.105" 1/16 0.105" 5/32" 0.105" * * 5/8     GP.3882
1936 348 OHC KSS MkII 6.8 to 1 Slipper Design Al 74.00 2.9134 WP.1536   1 13/16 3 1/8       Dome 3 1/16 0.105" 1/16 0.105" 5/32" 0.105" * * 5/8     158E.64
1936-47 348 OHC KSS Mk II Slipper Type 7.5 to 1 Al 74.00 2.9134 3874   1 29/32 3 7/32       Dome 3 1/16 0.105" 1/16 0.105" 5/32" 0.105" * * 5/8     GP.3874
1935/47 495 OHV MSS CR 6 to 1 Al 81.00 3.189 3889   1 13/16 3 5/16       Dome (with valve pockets) 3 2mm 0.116" 2mm 0.116" 4mm 0.116" * * 0.8236     GP.3889
1954 499 OHV MSS Al (52) 86.00 3.3858 1883   2.011 3.292       Dome 3 5/64 0.138" 5/64 0.138" 5/32" 0.138" * * 0.8236     2.09E+05
  499 OHV MSS Split skirt Iron barrel Al (52) 86.00 3.3858 1883 -13 M27-30 2.011 3.292 3.3838 0.002 15.00 oz Dome 3 5/64 0.138" 5/64 0.138" 5/32" 0.138" * * 0.8236     2.09E+05
1954/6 499 OHV MSS Scrambler / VM CR 8:1 Al (52) 86.00 3.3858 1883-07   2.369 3.65       Dome (with valve pockets) 3 5/64 0.138" 5/64 0.138" 5/32" 0.138" * * 0.8236     2.09E+05
1954/6 499 OHV MSS Scrambler / VM CR 9:1 Al (52) 86.00 3.3858 1883-08   2.422 3.703       Dome (with valve pockets) 3 5/64 0.138" 5/64 0.138" 5/32" 0.138" * * 0.8236     2.09E+05
  499 OHV MSS Scrambler / VM CR 9:1 Split skirt Iron barrel Al (52) 86.00 3.3858 1883-14   2.422 3.703 3.3838 0.002 14.75 oz Dome (with valve pockets) 3 5/64 0.138" 5/64 0.138" 5/32" 0.138" * * 0.8236     2.09E+05