Inspection · F1 / F2

Octane engine inspection

For CFR F1 research and F2 motor methods. Checks and calibration review before deciding to open the crankcase for overhaul.

When to schedule

Worth a check even before the hour interval

After a seasonal restart, a long idle, or a sudden drop in reference-fuel repeatability, inspect before replacing assemblies. On combination units switching research to motor method, intake humidity, mixture heat and ignition must be switched as a set — not only the compression-ratio handwheel.

Public CFR Engines service guidance often discusses F1/F2 top-end overhaul around 100–150 operating hours. That interval is for overhaul, not for this inspection. Inspection decides whether that interval has been reached.

On site

Checklist by condition, not by hearsay

Typical items on site or in the shop. Tolerances follow the ASTM or GB text the laboratory runs.

Nameplate, model, classic gauges vs digital control
Coolant temperature, flow and leaks
Oil level, pressure, emulsion
Compression-ratio scale backlash to the same mark
Intake temperature probe still in the original location
Research-method humidity control or ice-tower piping in use
Motor-method mixture heat vs temperature display
Four-bowl levels, needle-valve seep, cross-feed between bowls
Ignition advance appearance, spark plug and HT lead
Knockmeter zero after warm-up; return after a light tap
Pickup washer, torque, and signal cable away from heat
Exhaust free, fuel drip-free, grounding sound

Recent reference-fuel raw records from the laboratory are more useful than a single verbal description.

What you receive

An inspection record with measured conditions, anomalies and a clear recommendation: continue rating, adjust, or stop for tear-down. Formal standard reports remain the laboratory’s responsibility.

Next step

Tell us the engine model, the symptom, and the last rating run

A nameplate photo helps: research method, motor method, or cetane, and where the reading drifts.