B58 Engine, Internals and Ignition

The B58's closed-deck block and forged crank handle a lot on stock internals, which is why most builds never open the engine. Spark plugs and coils are the exception: on a tuned car, plugs one or two steps colder, gapped tighter and changed more often are cheap insurance against misfires.

Built-motor parts (pistons, rods, head studs, MLS head gaskets, cams) come in when a big turbo and a power goal past the stock rods call for them. Plan the whole build first: internals only make sense with the fuel system, turbo and tune to match.

See Best B58 mods, in order for where a built motor fits in. Some plugs and coils here also fit the S58 in the M2, M3, M4, X3 M and X4 M; see the S58 parts page.