Engine Sizes

Engine Displacement and Sizes

Determining your next engine size can be quite difficult without a reference. Check out the CMDIY standard bore, engine size chart to figure out how big your current engine is, or how big you'd like your next build to be!

Standard Standard Overbore Different Stroke
Engine Variations
Original Block
Engine Size
Bore Size
Over Bore
Estimated Power
Estimated Torque

850850cc2.58" / 62.9mm----2.688" / 68.26mm (std)34bhp44lb/ft

997997cc2.458 / 62.43mm----3.200" / 81.28mm (std)55bhp54lb/ft

998998cc2.543" / 64.57mm----3.000" / 76.20mm (std)41bhp52lb/ft

9981014cc2.563" / 65.09mm+0203.000" / 76.20mm (std)--------

9981030cc2.583" / 65.60mm+0403.000" / 76.20mm (std)--------

9981046cc2.603" / 66.10mm+0603.000" / 76.20mm (std)--------

9981098cc2.543" / 64.58mm----3.296" / 83.72mm45bhp56ft/lb

9981114cc2.563" / 65.09mm+0203.296" / 83.72mm--------

9981132cc2.583" / 65.60mm+0403.296" / 83.72mm--------

9981149cc2.603" / 66.10mm+0603.296" / 83.72mm--------

12751275cc2.78" / 70.6mm----3.200" / 81.28mm (std)63bhp70lb/ft

12751293cc2.801" / 71.145mm+0203.200" / 81.28mm (std)--------

12751302cc2.811" / 71.4mm+0303.200" / 81.28mm (std)--------

12751311cc2.821" / 71.65mm+0403.200" / 81.28mm (std)--------

12751330cc2.841" / 72.16mm+0603.200" / 81.28mm (std)--------

12751361cc73mm73.003.200" / 81.28mm (std)--------

12751379cc73.5mm73.503.200" / 81.28mm (std)--------

12751398cc74mm74.003.200" / 81.28mm (std)--------





Image of my car on jack stands


Classic Mini DIY is completely free resource supported by our viewers. If you are interested in helping to keep the channel alive, consider supporting on Patreon.

Membership comes with tons of free perks and benefits!

Contribute Today

Classic Mini DIY by Cole Gentry .

Classic Mini DIY toolbox is a passion project aligned with the Classic Mini DIY youtube channel. This is a completely free resource built to keep the Classic Mini technical knowledgebase alive for years to come. Regularly updated and crowd sourced data made to help Classic Mini owners all over the world.

2024 — Classic Mini DIY LLC