Overview#
The Gillette SP-8000 is an 800-kilowatt natural gas stationary standby generator — natural gas only, three-phase, built on PSI's 39.2L turbocharged V12. It produces 1,234 bhp at standby on NG — the largest PSI V12 displacement before stepping to the 52.3L V16 in the SP-1M. Stamford HCI634G alternator, DSE 7420 MKII with UL 6200 certification, four-battery 24V starting system.
At 800 kW, this is a mission-critical utility-class standby generator: data centers requiring full-UPS bypass backup, large hospitals, major campus distributions, and industrial facilities with continuous-operation requirements.
The PSI 39.2L V12 — long-stroke architecture#
The SP-8000 uses PSI's 39.2L V12 rather than a larger-bore version of the 31.8L SP-6500 engine. Key differences:
- 39.2L vs. 31.8L — longer stroke (7.28" vs. 5.91") at the same bore (5.91"), 23% more displacement from stroke extension
- Long-stroke design produces higher torque at 1800 RPM — beneficial for load acceptance in large critical facilities
- 2,392 cu in — among the largest naturally-counted displacement spark-ignition engines produced for the generator market
- Single 12" exhaust outlet — a design change from the dual 6" outlets of the SP-6500
- 127 qt oil capacity (154 qt with 6 filters) — very large oil system requiring 6 filters and planned oil change logistics
The long stroke configuration at 1800 RPM produces higher piston speed (2,185 ft/min) than the SP-6500 (1,772 ft/min), which is a consideration for long-service-life planning and overhaul scheduling.
Fuel demand and gas service design#
10,109,000 BTU/hr at full load is a substantial gas demand — nearly 10 MMBTU/hr. Dual 3" NPTF inlets at 20-30" water column (higher pressure than smaller models). This typically requires:
- Dedicated 4" or larger high-pressure gas main from utility
- On-site pressure regulator sized for full-load flow
- Utility pre-planning and potentially a gas capacity reservation
At this scale, engage your gas utility and a licensed gas engineer as early-phase design activities, not permit-stage activities.
Our service experience#
At 800 kW natural gas, the SP-8000 is at the upper boundary of what we commission and service for commercial and institutional clients in our territory. These units require a structured preventive maintenance program with annual full-load testing — no exceptions. The 12-cylinder ignition service is a multi-technician, full-day event. We treat the four-battery starting system as a safety-critical component: battery capacity testing is included in every annual service, not just when a start failure occurs.
