big end

plural big ends

1. In a piston engine, the larger end (crankshaft end) of the connecting rod that connects a piston to the crankshaft.

   From the sound of that motor, I'd say yer big end's gone, mate.

   2 more examples

   Except in the case of the largest 4-6-2, not yet in contemplation, use of two [outside] cylinders only was decided on for the following reasons:— […] 2. The split inside big end is a source of trouble at high speeds and powers unless exceptional integrity of maintenance can be guaranteed.

   1951 July, “British Standard Locomotives”, in Railway Magazine, page 441

   Oil is carried from the big end to the small end by a centrally drilled oil hole.

   1958 April 28, “British Railways First Main-Line Diesel-Hydraulic Locomotive”, in Railway Magazine, page 265

   Antonyms: small end