Compstar H/5 Crankshaft
5.000" Spread Bore BBC
Purpose built specifically for Extreme Displacement high horsepower applications, H/5 crankshafts exemplify High Value design. Starting with a blank sheet of paper, Compstar engineers set out with only one goal in mind: "create the strongest, most durable crankshaft value for Extreme Displacement engines."
H/5 is an outstanding example of High Value material. Each H/5 is produced from true AISI 4340 steel that is mill certified and examined by our metallurgist prior to acceptance. All H/5 crankshafts receive the Callies/ Compstar Ultra-Case nitrite surface treatment, resulting in an effective case depth of .020 inch. This deep nitride generates a compressive stress layer that strengthens and hardens the entire shaft.
H/5 crankshafts incorporate unique and proprietary Overlap Bars that are strategically placed in the overlap area between each rod and main journal. These Overlap Bars improve stiffness while significantly reducing bending fatigue. This added stiffness is especially important in long stroke Extreme Displacement engines. With their mass focused close to the crank centerline, Overlap Bars greatly improve strength with minimal influence on balance.
We believe with High Value design, each H/5 provides you with the best Steel, Heat Treatment, Material Distribution, and Precision of any crankshaft in this class. H/5 cranks are available in 5.375 and 5.500 strokes.
The H5 is fully counterweighted
Overlap bars increase the strength of the long stroke H5
Front view of the H5 overlap bars
H/5 Rear View
H/5 Overall View