Oil Cooler Line Sizing Calculator
Input your engine's displacement and power output to determine the correct AN hose and fitting size for oil cooler feed and return lines, recommended cooler core dimensions, estimated flow rates, and critical oil temperature guidance for street and track use.
Engine Specification
Number of Coolers
Recommendations
Feed / Return Line
-8 (AN8)
12.7mm / 1/2"
Est. Oil Flow
8–14
L/min
Cooler Size
34-row
450 × 180mm (competition)
Cooler Count
1
N/A
Naturally aspirated engines have moderate oil heat. A thermostat sandwich plate is recommended to maintain ideal oil temperature (90–110°C).
AN Size Velocity @ Estimated Flow (max)
| AN Size | Bore ID | Area (mm²) | Velocity (m/s) | Assessment |
|---|---|---|---|---|
| -6 | 9.5 mm | 70.9 | 3.29 | Optimal |
| -8 | 12.7 mm | 126.7 | 1.84 | Optimal |
| -10 | 15.9 mm | 198.6 | 1.18 | Oversized |
| -12 | 19 mm | 283.5 | 0.82 | Oversized |
| -16 | 25.4 mm | 506.7 | 0.46 | Oversized |
Oil Temperature Reference
Installation Guidelines
Always fit an oil thermostat. A sandwich plate thermostat (typically opening at 80–85°C) prevents overcooling during warm-up and on cool days. Running cold oil causes as much wear as running hot.
Feed from the block, return to the block. Connect to the factory oil pressure port (or sandwich plate) for feed. Return to the block — never directly to the sump — to ensure proper filtration.
Cooler placement matters. Position the cooler in a high-airflow area (front of car, behind grille opening). Avoid locations shielded from airflow at low speeds such as the inner wheel arch.
Turbo oil drain priority. On turbocharged engines, ensure the turbo oil drain line is gravity-fed and adequately sized (-10 or -12 AN) to prevent oil backing up in the turbo bearing housing.