In an effort to increase productivity, and profits, many aftermarket automotive performance engine component manufacturers in the United States have discontinued supplying important internal engine components such as crankshafts and connecting rods. A lack of available parts can create unique challenges for those in the performance and restoration engine rebuilding industry.
One engine model that has seen a significant reduction of available parts is the turbo Buick 3.8L engine. Popular aftermarket engine component manufacturers such as Eagle have discontinued selling forged connecting rods for these engines. Other options exist for the engine builder, but the reduced competition has driven up costs.
Crankshafts, once sold by both Eagle and Cat are no longer available. Those wishing to rebuild a Buick V6 engine, with a steel forged crankshaft, must look to other sources to assemble a forged rotating assembly for these high performance engines. Since a properly tuned turbo Buick engine can easily run nine seconds in the quarter mile, with the right internal engine components, the crankshaft is the most important rotating component of an engine that is being built to handle high horsepower.
Few aftermarket crankshaft suppliers exist for the 3.8L turbo charged Buick V6 engine. However, exporting countries such as China have seized on the opportunity to manufacture their own crankshafts for turbo Buicks. At the present time, Chinese manufacturers are exporting both 3.400 standard stroke and 3.625 stroker crankshafts to the United States.
We have inspected a good number of aftermarket crankshafts from China. Overall, they appear to be a solid piece. However, a few areas of concern should be addressed by those purchasing one of these cranks. The turbo Buick crankshafts from China typically have a crank keyway that must either be modified or a special key would need to be used for the harmonic balancer. Another area of the forged crankshaft that may need additional machine work is the flywheel flange area. Unlike American made crankshafts, the Chinese version has a large radius where the flywheel mounts at. This can cause the flywheel to not seat properly against the rear flange. Either the flywheel needs to be modified or the radius machined out of the rear crankshaft flange.
The finish grind on Chinese made crankshafts is average at best. Crank pin and main journal taper has checked within tolerance on most pieces. Journal out of round was limited and within specification on most pieces. We did need to complete a crankshaft grinding operation on a few of the crankshafts we inspected. But the overall majority of these crankshafts are within tolerance and have specifications which make them suitable for high performance applications.
It is important to note that the Chinese made 3.8L forged crankshafts should be internally balanced. While internal balancing is common for most performance applications, customers must be advised that additional expenses involving harmonic balancer and flexplate balancing or replacement will be required.
Overall, the quality and dependability of Chinese made crankshafts appears average. When customers are faced with few affordable choices for a forged crankshaft for their turbo Buick engine, imported automotive crankshafts have proven to be a dependable product that does not bust the budget.