What does a Stage 1 Predator 212 make?
Engine output on a stand — there is no drivetrain and no chassis in these numbers, which is the same basis Harbor Freight rates the engine on. Simulated at 800 ft and 75°F; thinner air makes less power and wants less fuel, so both the horsepower and the jet move with them. Governor removed. Compression 9.06:1.
Where each one wins
| RPM | Stage 1 | governor out only | diff |
|---|---|---|---|
| 1500 | 2.42 | 2.07 | -0.35 |
| 2000 | 3.33 | 2.85 | -0.48 |
| 2500 | 4.28 | 3.66 | -0.62 |
| 3000 | 5.27 | 4.51 | -0.75 |
| 3500 | 6.33 | 5.42 | -0.91 |
| 4000 | 7.44 | 6.36 | -1.08 |
| 4500 | 8.60 | 7.34 | -1.26 |
| 5000 | 9.81 | 8.24 | -1.57 |
| 5500 | 10.26 | 8.24 | -2.02 |
Horsepower at each rpm. Everything except the part named is identical between the two runs.
The classic first build: an angled pod filter, a header, 18 lb valve springs so the stock cam stops floating, a bigger carb and a jet to match.
Every part in that list is cheap, and together they do more than any one of them suggests. The comparison here is against the same engine with only the governor gone, so what you are seeing is what the hardware adds on top of the rpm you already unlocked.
Do the jet with the filter and header. Adding airflow without adding fuel leans the engine out, and a lean 212 is a holed piston waiting for a warm day.
The build
| Engine | Predator 212 Hemi (Gen 2) — 27/25mm valves · 5.5mm stems |
|---|---|
| Governor | Governor removed (full rev range) |
| Piston | Stock flat top — Hemi OEM (ARC DJ-1285PH · .550" CH) |
| Head | Stock Hemi head — as-cast factory |
| Head gasket | Stock HEMI — fiber .045" (ARC DJ-1310TP) |
| Camshaft | Stock cam — Hemi & Non-Hemi factory grind |
| Valve springs | 18 lb Hemi specific (OMB/GPS) |
| Retainers | Stock retainers — OEM (ARC DJ-1040) |
| Valves | Stock valves — OEM |
| Rocker arms | Stock rocker arm — 1:1 ratio |
| Connecting rod | ARC 6256 Billet — Hemi (+.020" raises CR) |
| Flywheel | ARC 6696 Billet — Hemi Speedway (32° BTDC) |
| Ignition coil | Stock coil — factory (no rev limiter) |
| Carburetor | 22mm clone carb — GPS / OMB Stage kit carb |
| Air filter | Pod / cone filter — GPS / OMB angled filter kit |
| Exhaust | GPS header + screw-on muffler kit |
| Fuel | Pump 87 octane |
The other one
| Engine | Predator 212 Hemi (Gen 2) — 27/25mm valves · 5.5mm stems |
|---|---|
| Governor | Governor removed (full rev range) |
| Piston | Stock flat top — Hemi OEM (ARC DJ-1285PH · .550" CH) |
| Head | Stock Hemi head — as-cast factory |
| Head gasket | Stock HEMI — fiber .045" (ARC DJ-1310TP) |
| Camshaft | Stock cam — Hemi & Non-Hemi factory grind |
| Valve springs | Stock springs (~10.8 lb) |
| Retainers | Stock retainers — OEM (ARC DJ-1040) |
| Valves | Stock valves — OEM |
| Rocker arms | Stock rocker arm — 1:1 ratio |
| Connecting rod | ARC 6256 Billet — Hemi (+.020" raises CR) |
| Flywheel | ARC 6696 Billet — Hemi Speedway (32° BTDC) |
| Ignition coil | Stock coil — factory (no rev limiter) |
| Carburetor | Stock Mikuni clone 18mm — Hemi factory |
| Air filter | Stock foam filter — factory |
| Exhaust | Stock muffler — factory |
| Fuel | Pump 87 octane |