CALLIES ULTRA BILLET CRANKSHAFT - 4.000" STROKE - CLEVELAND MAINS - APO-71@-UB

Our Ultra Boost (UB) family of crankshafts represent the pinnacle of severe duty shafts. Designed specifically for the most harrowing, ultra-high output applications where no exceptions are to be made for reliability, years of experience and talent culminate to shape the industry’s most capable crankshaft. Each Ultra Boost crank is machined from Callies renowned 4330 bar stock, sourced from TimkenSteel right here in Ohio. Taking lessons from the Top Fuel world, where our crankshaft routinely outperforms the competition, we’ve implemented similar design language into the Ultra UB line. Two of the most prominent changes include increased material found on the pin arms and pin tops. These changes, along with others, allow for the most reliable crankshaft that is offered today— helping make sure you spend more time at the track than in the shop.

Callies has developed a wide range of part numbers for the continually evolving and popular LS family of engines.  Any main journal, rod journal, post configuration,  stroke or other specialized characteristic that you may require can be provided. Callies Ultra billet UB crankshafts are truly custom made to match your project.

Standard Features:

Stroke Range: 2.720 in – 4.750 in.
LS1, LS7, LT1 posts are available
6, 8, or 9 bolt pattern flange options
Rod Sizes: 1.850, 1.888, 2.000, 2.100, 2.200 w/sbc width, 2.200 BBC width
Main Journal Sizes: Standard LS, Ford Cleveland 351
8 or 6 counterweight designs available
No drill finish balancing available upon request
Aero efficient Ultra-Shed counterweight profiling is standard
Aeroshed super finishing included with all Ultra Billets
All Ultra LS boosts are produced from TimkenSteel 4330 alloy steel