Seals the oil cooler fan to the oil-to-air heat exchanger core.
Same role as the water fan shroud on the smaller oil circuit: holds the 5.2 in Spal fan against the core and prevents bypass.
No part-specific design process is documented. The Cooling, Aerodynamics subsystem design process applies: 1. Powertrain sets the required heat rejection from previous-year endurance data; that becomes a target mass airflow (CR26I: 0.265 kg/s water, 0.060 kg/s oil). 2. Characterise the core on the flow bench to get pressure drop against velocity, and fit Darcy-Forchheimer coefficients (water radiator viscous 1,919,749.6, inertial 52.945; oil cooler viscous 7,387,951.3, inertial 132.358). 3. Model the core in ANSYS Fluent as a porous region and the fan as a pressure jump over a fan boundary, using the manufacturer fan curve. 4. Sweep radiator angle. CR26I found 0 deg gave 0.459 kg/s with 0.78 lbf drag, +45 deg forward lean gave 0.343 kg/s with 0.31 lbf drag. Forward lean was accepted because it still beat target and cut drag and lift. 5. Design the duct and shroud around the chosen core position, then validate the assembled system with tufting and coast-down testing.
3D printed directly in PA6-GF rather than laid up, because the part is small enough that printing is faster and stiff enough.
PA6-GF30 (glass-filled nylon), 3D printed. From the cost report drawings and CAD: From the cost report drawings: PA6-GF30 (Oil Cooler Fan Shroud rev003).
None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.
Sized around the Spal VA31-A101-46A 5.2 in fan (approximately 244 CFM, 0.902 lb, 4.6 A maximum draw). From the cost report drawings and CAD: Measured mass, as built: CR25 564.0 g (1.243 lb) (weighed as: Oil cooler fan + shroud). CAD mass, CR26I master assembly: 0.620 lb (0.281 kg). CG at X 51.88 in, Y 16.09 in, Z 9.24 in in vehicle coordinates. (CAD component: Oil Cooler Fan Shroud rev003) Dimensions called out on the cost report drawings. These are the figures printed on the drawing, not a labelled specification; open the drawing itself for what each one refers to. Oil Cooler Fan Shroud rev003 (as drawn): 6.50, 0.65, 100.58, 10.06, 101.83, 10.18, 246.06, 24.61, 105.02, 10.50 Source: CR26e Weight Tracker.xlsx, Final IRL Weights (weighed, not CAD) | SolidWorks mass model exports: CR22 (5 May 2024), CR25 (4 Jul 2025), CR26I (30 Jul 2025), CR26E (22 Mar 2026) | Cost report drawings: CR25/Powertrain/Design/Y - Cost Report Drawings/Lubrication/Oil Cooler Fan Shroud rev003.pdf; CR26i/Powertrain - IC/Design/Y - Cost Report Drawings/Lubrication/Oil Cooler Fan Shroud rev003.pdf; CR27i/.Powertrain/Design/Y - Cost Report Drawings/Lubrication/Archive/Oil Cooler Fan Shroud rev003.pdf Quantity per car, as costed: 1
Nothing in CrimsonStorage covers these yet.