PROJECT DART 427W, PART 2
We machine the block, balance the crank and check clearances.
The Dart Iron Eagle 351W block is a precision-cast and raw-machined product of unparalleled quality. Dart provides a bit of extra deck height and minimal bore diameter, allowing the builder to precisely achieve desired dimensions.
By Mike Mavrigian
all photos by author
CYLINDER BORES AND BLOCK DECK MACHINING
Our block was finish-machined by Scott Gressman at Gressman Powersports (Fremont, OH…a mere 80 mile drive west of my shop).
Cylinder boring and deck surfacing was handled on Gressman’s RMC CNC machine, taking advantage of RMC’s block blueprint software for the Dart 351W Iron Eagle block.
Our Dart Iron Eagle 351W block was delivered with 4.000” rough-machined bores. Our JE pistons (P/N 232474) feature a skirt diameter of 4.1205”. JE recommends a piston to bore clearance of 0.005”, so our bores required a finished size of 4.1255”.





