etc

A Series Engine Capacities


Many questions exist regarding differing bore and stroke capacities of the A series motor for our Sprites and Midgets. The following tables lists the more common bore and stroke combinations, courtesy of Steve Koen.

 

 
 A series engine bore and stroke comparisons
 		 
 
  
  
  
  
  
  
  
  
  
  
 
  
 		Imperial
  
  
  
  
 
  
  
  
  
  
  
  
  
  
  
 
 Nominal engine capacity
 		948cc
 948cc
 998cc
 998cc
 1098cc
 1275cc
 1275cc
  
 
 Std stroke
  
 3.00 inches
  
 3.00 inches
  
 3.30 inches
 3.20 inches
  
  
 
 Long stroke
  
  
 3.30 inches
  
 3.30 inches
  
  
 3.30 inches
  
 
 Std bore
  
 2.48 inches
 2.48 inches
 2.54 inches
 2.54 inches
 2.54 inches
 2.78 inches
 2.78 inches
  
 
 Capacity
  
 57.8 cubic inches
 63.5 cubic inches
 60.9 cubic inches
 67.0 cubic inches
 67.0 cubic inches
 77.7 cubic inches
 80.0 cubic inches
  
 
  +0.010" bore
  
 2.49 inches
 2.49 inches
 2.55 inches
 2.55 inches
 2.55 inches
 2.79 inches
 2.79 inches
  
 
 Capacity
  
 58.4 cubic inches
 64.2 cubic inches
 61.3 cubic inches
 67.3 cubic inches
 67.3 cubic inches
 78.3 cubic inches
 80.6 cubic inches
  
 
  +0.020" bore
  
 2.50 inches
 2.50 inches
 2.56 inches
 2.56 inches
 2.56 inches
 2.80 inches
 2.80 inches
  
 
 Capacity
  
 58.7 cubic inches
 64.5 cubic inches
 61.9 cubic inches
 68.0 cubic inches
 68.0 cubic inches
 78.6 cubic inches
 80.9 cubic inches
  
 
  +0.030" bore
  
 2.51 inches
 2.51 inches
 2.57 inches
 2.57 inches
 2.57 inches
 2.81 inches
 2.81 inches
  
 
 Capacity
  
 59.2 cubic inches
 65.0 cubic inches
 62.4 cubic inches
 68.5 cubic inches
 68.5 cubic inches
 79.1 cubic inches
 81.5 cubic inches
  
 
  +0.040" bore
  
 2.52 inches
 2.52 inches
 2.58 inches
 2.58 inches
 2.58 inches
 2.82 inches
 2.82 inches
  
 
 Capacity
  
 59.7 cubic inches
 65.6 cubic inches
 62.9 cubic inches
 69.1 cubic inches
 69.1 cubic inches
 79.7 cubic inches
 82.1 cubic inches
  
 
  +0.060" bore
  
 2.54 inches
 2.54 inches
 2.60 inches
 2.60 inches
 2.60 inches
 2.84 inches
 2.84 inches
  
 
 Capacity
  
 60.8 cubic inches
 66.8 cubic inches
 63.9 cubic inches
 70.2 cubic inches
 70.2 cubic inches
 81.1 cubic inches
 83.5 cubic inches
  
 
 73mm bore
  
 n/a
 n/a
 n/a
 n/a
 n/a
 2.87 inches
 2.87 inches
  
 
 Capacity
  
 n/a
 n/a
 n/a
 n/a
 n/a
 83.0 cubic inches
 85.5 cubic inches
  
 
 73.5mm bore
  
 n/a
 n/a
 n/a
 n/a
 n/a
 2.89 inches
 2.89 inches
  
 
 Capacity
  
 n/a
 n/a
 n/a
 n/a
 n/a
 84.2 cubic inches
 86.7 cubic inches
  
 
 74mm bore
  
 n/a
 n/a
 n/a
 n/a
 n/a
 2.91 inches
 2.91 inches
  
 
 Capacity
  
 n/a
 n/a
 n/a
 n/a
 n/a
 85.3 cubic inches
 87.9 cubic inches
  
 
  
  
  
  
  
  
  
  
  
  

 

 

  
 A series engine bore and stroke comparisons
 		 
 
  
  
  
  
  
  
  
  
  
  
 
  
 		Metric
  
  
  
  
 
  
  
  
  
  
  
  
  
  
  
 
 Nominal engine capacity
 		948cc
 948cc
 998cc
 998cc
 1098cc
 1275cc
 1275cc
  
 
 Std stroke
  
 76.20 mm
  
 76.20 mm
  
 83.72 mm
 81.28 mm
  
  
 
 Long stroke
  
  
 83.72 mm
  
 83.72 mm
  
  
 83.72 mm
  
 
 Std bore
  
 62.90 mm
 62.90 mm
 64.59 mm
 64.59 mm
 64.59 mm
 70.61 mm
 70.61 mm
  
 
 Capacity
  
 947 cc
 1,041 cc
 999 cc
 1,097 cc
 1,097 cc
 1,273 cc
 1,311 cc
  
 
  +0.010" bore
  
 63.25 mm
 63.25 mm
 64.77 mm
 64.77 mm
 64.77 mm
 70.87 mm
 70.87 mm
  
 
 Capacity
  
 958 cc
 1,052 cc
 1,004 cc
 1,103 cc
 1,103 cc
 1,282 cc
 1,321 cc
  
 
  +0.020" bore
  
 63.41 mm
 63.41 mm
 65.10 mm
 65.10 mm
 65.10 mm
 71.01 mm
 71.01 mm
  
 
 Capacity
  
 962 cc
 1,057 cc
 1,015 cc
 1,115 cc
 1,115 cc
 1,288 cc
 1,326 cc
  
 
  +0.030" bore
  
 63.66 mm
 63.66 mm
 65.35 mm
 65.35 mm
 65.35 mm
 71.26 mm
 71.26 mm
  
 
 Capacity
  
 970 cc
 1,066 cc
 1,022 cc
 1,123 cc
 1,123 cc
 1,297 cc
 1,336 cc
  
 
  +0.040" bore
  
 63.92 mm
 63.92 mm
 65.61 mm
 65.61 mm
 65.61 mm
 71.51 mm
 71.51 mm
  
 
 Capacity
  
 978 cc
 1,074 cc
 1,030 cc
 1,132 cc
 1,132 cc
 1,306 cc
 1,345 cc
  
 
  +0.060" bore
  
 64.52 mm
 64.52 mm
 66.12 mm
 66.12 mm
 66.12 mm
 72.14 mm
 72.14 mm
  
 
 Capacity
  
 997 cc
 1,095 cc
 1,047 cc
 1,150 cc
 1,150 cc
 1,329 cc
 1,369 cc
  
 
 73mm bore
  
 n/a
 n/a
 n/a
 n/a
 n/a
 73.00 mm
 73.00 mm
  
 
 Capacity
  
 n/a
 n/a
 n/a
 n/a
 n/a
 1,361 cc
 1,402 cc
  
 
 73.5mm bore
  
 n/a
 n/a
 n/a
 n/a
 n/a
 73.50 mm
 73.50 mm
  
 
 Capacity
  
 n/a
 n/a
 n/a
 n/a
 n/a
 1,379 cc
 1,421 cc
  
 
 74mm bore
  
 n/a
 n/a
 n/a
 n/a
 n/a
 74.00 mm
 74.00 mm
  
 
 Capacity
  
 n/a
 n/a
 n/a
 n/a
 n/a
 1,398 cc
 1,440 cc