The turbo/intercooled Syclone engine is the latest variant off the famed GM 90° small block engine platform. Application is specifically to the Syclone short wheelbase all wheel drive pickup truck to be marketed by GMC in 1991. The engine project was a joint venture between General Motors Powertrain Division and PAS TRIAD of Troy, Michigan. Engine manufacture will originate at the GMPD Romulus 4.3L plant with final assembly at the Shreveport vehicle assembly facilities of GMC Truck and Bus and PAS TRIAD.
Features of the engine include:
High specific performance (1430 KPa BMEP)
Air to water intercooling with an independent cooling loop.
Electronically controlled wastegate for boost and knock control.
High dynamic range multi-port fuel injection.
Communization with standard 4.3L engine where possible to facilitate manufacturing process and quality management.
Use of upgraded materials for highly stressed critical components including pistons, cylinder head gaskets, main bearing caps, and exhaust manifolds.
Time for concept to market was held to 18 months via an intensive concept evaluation, design/develpment program. The early engine feasibility work featured a “probe” durability test where the engine was run successfully at 600 N-m torque, approximately twice the BMEP of the standard 4.3L. Engine validation was done to a jointly developed test plan that was specifically tailored for the vehicle usage expected.
