CR21 naming for the engine mounting hardware.
Superseded by the engine pin arrangement, which integrates engine and differential carrier mounting.
No part-specific design process is documented. The Engine subsystem design process applies: 1. Characterise the engine experimentally rather than from published data. Intake port geometry captured by pouring 2-part casting silicone into the ports, then 3D scanning and post-processing the molds. Port flow measured on a flow bench with valve lift controlled by fine-pitch fasteners threaded into a plate bolted to the head, read on dial indicators, with an individually characterised bell mouth adapted to the port inlet. 2. Measure camshaft geometry with a dial indicator rigidly mounted to the head probing the lobe surface, combined with lifter geometry to get the effective lift profile. CR26I: exhaust 180 deg ECD at 0.050 in lift, 7.95 mm max lift at 245 deg ATDC; intake 200 deg ECD, 8.67 mm max lift at 475 deg ATDC; 115 deg LSA, 150 deg overlap. 3. Measure valve spring force-displacement on an MTS Exceed, averaging multiple springs. Maximum displacement limited by coil bind at 0.9270 in. 4. Build the GT Suite model from those measurements and validate against dyno data. 5. Develop calibration on the engine test stand, then validate on track.
Milled on the CNC.
Aluminium.
Fault Vault, CR26I: engine mounting connected to the span of the main hoop brace was outlawed by the 2026 rules and the change was missed, causing an SES tech failure at competition.
Nothing in CrimsonStorage covers these yet.