T: (800) 992-7007

P: (530) 886-0771

P: (530) 777-7759

All orders ship from the U.S.A.

Keeping classic Minis on the road since 1974

(800) 992-7007 | (530) 886-0771


  • Condition: new
  • Sold -999
  • Made in the U.S.A.
  • DOT-approved False
  • This item qualifies for NESTED shipping; a pair can ship (almost) as cheaply as a single item!Nested Shipping Item
Price: $145.00
    SKU:  C-STR313
    Availability: Out of Stock
    Out of Stock
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    New design "Evo" 73mm piston for 1362cc big-bore engine conversion. Due to the increasing scarcity of 1300cc A and A+ series blocks, using a 73mm piston as the first big-bore oversize allows doubling the block's life. The 73mm piston gives 1362cc, for nearly identical performance to the 1380cc, yet the block can be safely rebored to 73.5mm at a later date. Plus the 73mm bore fits the existing standard gaskets better, avoiding an expensive big-bore gasket. Using a 21.4cc chamber and the BK450 black head gasket, this gives just under 10:1 with the piston down the bore .007". With the pistons at zero-deck, it gives 10.4:1. Note the rings are supplied unfitted so they can be gapped to .011-.014" range after boring to 73mm. These rings are slightly proud of the ring grooves in the piston, which is an unconventional configuration, but this is a tested design. Rings are USA made Hastings brand for ready availability. Pistons sold by the set, with rings and pins.

    Out of Stock

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