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 Second Width Ref. No. Third / Oil RingWidth Ref. No. Ring Below Pin Width Ref Pin Dia Pin Length Type Pin Ref No. R
1928/9 249 U Offset inlet port 1 Ύ” on Circumference at bottom of skirt Brass gudgeon pin buttons Cast Iron 63.00 2.4803 3145   1 29/32 3 27/32 62.93 0.003 12.25 oz   2 1/8” P157 1/8” P157 * * * * ½” 2 7/32” FF 1152B
1922/6 249 Inlet port 1 5/8” on Circumference at bottom of skirt Seeger rings Cast Iron 63.00 2.4803 1107   1 21/32” 3 29/32” 62.94 0.003 13.5 oz Two Stroke 2 3/32” P151 3/32” P151 * * * * ½” 55.5mm SC 1146A
1927 249 Inlet port 1 5/8” on Circumference at bottom of skirt Brass gudgeon pin buttons Cast Iron 63.00 2.4803 5275   1 21/32” 3 29/32” 62.91 0.004 9.25 oz Two Stroke 2 1/8” P157 1/8” P157 * * * * ½” 2 7/32” SC 1153B
1929 249 USS 48mm Offset Port 48mm at Bottom of Skirt   Al 63.00 2.4803 4940   1 25/32” 4 1/32” 62.85 0.006   Two Stroke 2 3/32” P151 3/32” P151 * * * * ½” 55.5mm SC 1146A
1930/1 249 GTP inlet port 1 5/16” on circumference at bottom of skirt Seeger rings Al 63.00 2.4803 2223   1 Ύ” 4” 62.87 0.005   Two Stroke 2 1/8” P157 1/8” P157 * * * * ½” 2 3/16” SC 31A
1930/3 249 GTP inlet port 1 Ύ” on circumference at bottom of skirt Seeger rings Al 63.00 2.4803 4335   1 Ύ” 4” 62.85 0.006   Two Stroke 2 1/8” P157 1/8” P157 * * * * ½” 2 3/16” SC 31A
1934/40 249 GTP inlet port 1 1/16”  on circumference in middle of skirt Seeger rings Al 63.00 2.4803 4378   1 25/32 4  1/32 62.92 0.003 7.75 oz Two stroke 2 3/32” P151 3/32” P151 * * * * ½” 2 3/16” SC 31A
1932/3 249 GTP inlet port 1 5/16”  on circumference at bottom of skirt   Al 63.00 2.4803 4102   1 25/32 4  1/32 62.85 0.006 7.5 oz Two stroke 2 3/32” P151 3/32” P151 * * * * ½” 2 3/16” SC 31A
1932/3 249 GTP offset inlet port 1 Ύ” on circumference at bottom of skirt   Al 63.00 2.4803 4329   1 25/32” 4 1/32” 62.85 0.006   Two Stroke 2 3/32” P151 3/32” P151 * * * * ½” 2 3/16” SC 1146A
1934/40 249 GTP inlet port 1 1/16” on circumference in middle of skirt Seeger rings Al (412) 63.00 2.4803 4378   1 25/32 4  1/32 62.92 0.003 7.75 oz Two stroke 2 3/32” P151 3/32” P151 * * * * ½” 2 3/16” SC 31A
  249 GTP Wire circlips Al 63.00 2.4803 8852   1 25/32 4  1/32 62.88 0.005   Two stroke 2 3/32” P151 3/32” P151 * * * * ½” 2.214” RC10 3115A
  249 Offset inlet port  1 13/16” on circumference at bottom of skirt    Al 63.00 2.4803 4319   1 25/32” 4 1/32” 62.85 0.006   Two Stroke 2 3/32” P151 3/32” P151 * * * * ½” 2 3/16” SC 31A
1934/49 248 MOV Slipper Design CR 6.25 to 1 (Solid Skirt)   Al (412) 68.00 2.6772 4636   1 17/32 2 31/32 67.91 0.004 8.25 oz Dome (with valve pockets) 3 1/16” P275 1/16” P275 5/32" SDO 2165 * * 5/8” 60mm SC 1248A
1934/49 248 MOV Slipper Design CR 6.25 to 1 (Split Skirt)   Al (412) 68.00 2.6772 S4636   1 17/32 2 31/32 67.91 0.002 8.25 oz Dome (with valve pockets) 3 1/16” P275 1/16” P275 5/32" SDO 2165 * * 5/8” 60mm SC 1248A
1934/50 348 MAC Slipper Design CR 6 to 1 (Solid skirt, cast iron barrel only)   Al (412) 68.00 2.6772 4636   1 17/32 2 31/32 67.91 0.004 8.25 oz Dome (with valve pockets) 3 1/16” P275 1/16” P276 5/32" SDO 2165 * * 5/8” 60mm SC 1248A
1934/50 348 MAC Slipper Design CR 6 to 1 (Split skirt,
cast iron barrel only)		   Al (412) 68.00 2.6772 S4636   1 17/32 2 31/32 67.91 0.002 8.25 oz Dome (with valve pockets) 3 1/16” P275 1/16” P276 5/32" SDO 2165 * * 5/8” 60mm SC 1248A
1934/49 248 MOV Slipper Design (Solid Skirt)   Al (412) 68.00 2.6772 11559   1  9/16 3 67.91 0.004   Dome (with valve pockets) 3 1/16” P275 1/16” P276 5/32" DO 2165A * * 5/8”   RC40 3695A
1934/49 248 MOV Slipper Design (Split skirt)   Al (412) 68.00 2.6772 S11559   1  9/16 3 67.91 0.002   Dome (with valve pockets) 3 1/16” P275 1/16” P276 5/32" DO 2165A * * 5/8”   RC40 3695A
1934/50 348 MAC 6 or 6.75 to 1 Slipper Design (Solid Skirt)   Al (412) 68.00 2.6772 11559   1  9/16 3 67.91 0.004   Dome (with valve pockets) 3 1/16” P275 1/16” P276 5/32" DO 2165A * * 5/8”   RC40 3695A
1934/50 348 MAC 6 or 6.75 to 1 Slipper Design (Split skirt)   Al (412) 68.00 2.6772 S11559   1  9/16 3 67.91 0.002   Dome (with valve pockets) 3 1/16” P275 1/16” P276 5/32" DO 2165A * * 5/8”   RC40 3695A
  248 MOV Racing High Comp 10 to 1 Slipper Design   Al (402) Heat Treated 68.00 2.6772 10291   1 27/32 3  9/32 67.85 0.006 8.50 oz Special Dome 3 1/16” P5744 1/16” P5744 5/32" FSDO 5881B * * 5/8”   RC40 3695A
  348 MAC 8 to 1 Slipper Design   Al (402)  68.00 2.6772 10249   1 31/32 3 13/32 67.82 0.007   Special Dome 3 1/16” P5744 1/16” P5745 5/32" FSDO 5881B * * 5/8”   SC 1248A
  248 Pressed (forged) Piston   Al 68.00 2.6772 12526   2  3/32 2 15/16       Special 3 3/64” MDL7931 3/64” MDL7931 5/32" DO 7506 * * Ύ”   RC93 4726A
1956/66 349 Viper CR 8.5 to 1   H’lex 72.00 2.8346 W13323   2  7/16 3 11/16       Dome (with valve pockets) 3 1/16” TP10495  1/16” TP10495  5/32" EDO 12739 * * 0.8236   RC174 5213A
1934/39 348 KTT OHC   Al 74.00 2.9134 4900 K27-5 1 19/32” 2 25/32” 73.78 0.009   Dome 3 1/8” P445 1/8” P445 5/32" SDO 458 * * 0.8236 2 17/32” SC 1175A
  348 KTT CR 11.5 to 1   Al 74.00 2.9134 5450   2  3/32 3  7/16 73.81 0.007   Dome 3 1/16” P451 1/16” P451 5/32" SDO 458 * * 0.8236 2.610” RC100 1946A
  348 OHC   Al 74.00 2.9134 5150   1 3/4 3  1/16 73.78 0.009   Flat 3 1/8” P455 1/8” P455 5/32" SDO 458 * * 5/8” 2 19/32” SC 160A
  348 OHC Aluminium Buttons Al 74.00 2.9134 4078   1 7/8” 3 3/16” 73.81 0.007 10 oz Dome 2 1/16” P441 1/16” P441 * * * * 5/8” 2.5/8” FF 161B
  348 OHC   Al 74.00 2.9134 4350   1 31/32” 3 9/32” 73.82 0.007 9.75 oz Dome 3 1/16” P441 1/16” P441 5/32" SDO 458 * * 5/8” 2 19/32” SC 160A
  348 OHC   Al 74.00 2.9134 4471   1 13/16” 3 1/8” 73.79 0.008 8.5 oz Cone 3 1/16” P441 1/16” P441 5/32" SDO 458 * * 5/8” 2 19/32” SC 160A
1927/32 348 CR 7 to 1   Al 74.00 2.9134 2020 K27/6 1 7/8” 3 3/16” 73.79 0.008 9.75 oz Dome 3 1/8” P445 1/8” P445 5/32" SDO 458 * * 5/8” 2 19/32” SC 160A
1928 348 K High Comp   Al 74.00 2.9134 2523   1 27/32” 3 5/32” 73.77 0.009   Dome 3 1/16” P441 1/16” P441 5/32" SDO 458 * * 5/8” 2 19/32” CC  
1929 348 KTT CR 7 to 1   Al 74.00 2.9134 3183 K27-4 1 27/32” 3 7/32” 73.78 0.009   Dome 3 1/16” P451 1/16” P441 5/32" SDO 458 * * 0.8236 2 17/32” SC 1175A
1929 348 KTT CR 8.5 to 1   Al 74.00 2.9134 3315 K27-7 1 27/32” 3 5/32” 73.85 0.006 9 oz Dome 3 1/16” P451 1/16” P451 1/16” P451 * * 0.8236 2 17/32” SC 1175A
1929/30 348 KTS, KSS 10.25 to 1   H’lex or Al (402) Heat treated 74.00 2.9134 3351   2 1/8” 3 7/16” 73.85 0.006   Cone 3 1/16” P451 1/16” P451 1/16” P451 * * 5/8”  2 19/32” SC 160A
1929/31 348 KTP, KN   Al 74.00 2.9134 1415 K27 1 25/32”  3 3/32” 73.88 0.005   Cone Stepped 3 1/8” P445 1/8” P445 5/32" SDO 458 * * 5/8”  2 19/32” SC 160A
1929/31 348 KTT CR 10.25 to 1   Al 74.00 2.9134 4564 K27-8 1 21/32” 3 9/32” 73.78 0.009   Cone 3 1/16” P451 1/16” P451 1/16” P451 * * 0.8236 2 17/32” SC 1175A
1933 348 KTT CR 7.75 to 1   Al 74.00 2.9134 4534 K27/12? 1 25/32” 3 5/32” 73.78 0.009   Dome 3 1/16” P451 1/16” P451 5/32" SDO 458 * * 0.8236 2 17/32” SC 1175A
1932/35 348 KTS 6.5 to 1  Renumbered 5874 for die casting Al 74.00 2.9134 3909 K27-10 1 3/4 3  3/32 73.87 0.005 10.5 oz Dome 3 1/16” P451 1/16” P451 5/32" SDO 458 * * 5/8” 2 19/32” SC 160A
1934 348 KSS Slipper Design Renumbered 5874 for die casting Al  74.00 2.9134 3909   1 3/4 3  3/32 73.87 0.005 11 oz Dome 3 1/16” P451 1/16” P451 5/32" SDO 458 * * 5/8” 2 19/32” SC 160A
1936/47 348 KTT CR 11.5  to 1   Al 74.00 2.9134 3883   1 13/16” 3 1/8”   2.913   Dome 2 1/16” P451             0.8236     GP.3883
1936 348 KTS 6.8 to 1 Slipper Design   H’lex (405) 74.00 2.9134 5874   1 13/16” 3 1/8” 73.89 0.004 11.5 oz Dome 3 1/16” P451 1/16” P451 5/32" SDO 458 * * 5/8” 2 19/32” SC 160A
1936 348 KSS MkII 6.8 to 1 (Ring Below Pin)   Al (412) 74.00 2.9134 5875 K27/14 1 13/16 3 1/8 73.78 0.009 11.5 oz Dome 4 1/16” P451 1/16” P451 1/16” P451 1/16” P451 5/8” 2 19/32” SC 160A
1936-48 348  KSS Mk II Slipper Type 7.5 to 1   H’lex (405) 74.00 2.9134 7426 K27/17 1 29/32 3  7/32 73.90 0.004   Dome 3 1/16” P451 1/16” P451 5/32" SDO 458 * * 5/8” 2 19/32” SC 160A
1947-48 348  KSS Mk II Slipper Type (G.Pin .060” offset)   Al (402) Heat treated 74.00 2.9134 12041   1 57/64 3  1/4 73.82 0.007 10 oz 13 dr Dome (with valve pockets) 3 1/16” P5553 1/16” P5553 5/32" FSDO 5554B * * 5/8” 2 19/32” RC45 160A
    KDT   H’lex (405) 80.00   4109   1 7/8” 3 3/16” 79.89 0.004 11.5 oz Dome 3 3/32” P1122 3/32” P1122 5/32" SDO 516B * * 0.8236 2 Ύ” SC 1696A
1935/36 495 MSS CR 6 to 1 Slipper piston Original Veloce bottom of skirt clearance 0.006" Al 81.00 3.189 5304   1 13/16 3  5/16 80.88 0.005 12.75 oz Dome (with valve pockets) 3 2mm P2609 2mm P2609 4mm SDO 2610 * * 0.8236 2.610” RC100 1946A
1937/48 495 MSS CR 6 to 1 (Ring Below Pin) Original Veloce bottom of skirt clearance 0.006" Al (412) 81.00 3.189 5941   1 13/16 3  5/16 80.89 0.004 13 oz Dome (with valve pockets) 4 2mm P2609 2mm P2609 2mm P2609 2mm SS2947 0.8236 2.610” RC100 1946A
1954/60 499 MSS CR 6.8 to 1 Split skirt   H’lex (413) 86.00 3.3858 SW12249   2.011 3.292 85.93 0.003 15.25 oz Slight Dome  3 5/64” TP9744 5/64” TP9744 5/32" DO 9745 * * 0.8236   RC174 4698A
1954/60 499 MSS CR Hi Comp 8.5 to 1 Split skirt Based on 12249 H’lex 86.00 3.3858 W12759   2.31 3.591 85.93 0.003   Dome (with valve flats) 3 5/64” TP9744 5/64” TP9744 5/32" DO 9745 * * 0.8236   RC174 4698A
1955/60 499 Scrambler Venom Clubman 8.75 to 1    Al (402) Heat treated 86.00 3.3858 13324   2 27/64 3 45/64 85.82 0.007   Dome (with valve flats) 3 5/64” MTP13196 5/64” MTP13196 5/32" MDO 13197 * * 0.8236   RC174 5216A
1956/66 499 OHV Venom Endurance CR 8 to 1 (For Cast Iron Bores only) Split Skirt   H’lex (413) 86.00 3.3858 W13319   2.422" 3 45/64 85.93 0.003   Dome (with valve flats) 3 5/64” TP9744 5/64” TP9744 5/32" EDO 10618 * * 0.8236   RC174 4698A or 4698
1955/70 499 Scrambler Venom Clubman 8.75 to 1   AE Powermax 86.00 3.3858 18544   2 27/64 3 45/64       Dome (with valve flats) 1 5/64” KTP10617 5/64” MTP13196 5/32" MEDO12600 * * 0.8236   RC174 5216