12A Rebuild Parts
The following parts are recommended for all 12A rebuilds. Certain upgraded parts have been substituted, but may not be stock. These are the parts normally sent out when people want to order a basic rebuilt kit.
The parts in the top blue section may be ordered as one part number K-8185-2A-STK. The same kit, but with carbon apex seals and correct springs substituted can be ordered as K-8185-2A-RCE. Parts need to be ordered individually if ordering ceramic apex seals.
| DESCRIPTION | PART NUMBER | QTY | NOTES |
| APEX SEAL – STOCK | N201-11-300B | 6 | Click here for optional Apex Seals & Springs |
| APEX SPRING | 1011-11-304B | 6 | |
| CORNER SEAL | N225-11-321 | 12 | |
| CORNER SEAL SPRING | NF01-11-C24 | 12 | Washer type spring from 93-95 RX-7. Retains strength under high temperatures better than wire type design. |
| CORNER SEAL PLUG | N201-11-322 | 12 | |
| SIDE SEAL | 8871-23-151 | 12 | Precut |
| SIDE SEAL SPRING | 0820-11-317 | 12 | |
| OIL SEAL SET (STEEL) | N3Z1-11-S10A | 4 | 1 set is 1 inner and 1 outer. Needs 4 sets per engine. |
| O-RING – OIL SEAL OUTER | 0820-11-341 | 4 | Green |
| O-RING – OIL SEAL INNER | 1202-11-343 | 4 | Green – do not use 8341-11-343 black o-rings. |
| SPRING – OIL SEAL FRONT INNER | N225-11-351 | 2 | From 84-85 12A |
| SPRING – OIL SEAL REAR INNER | N225-11-361 | 2 | From 84-85 12A |
| SPRING – OIL SEAL FRONT OUTER | 4352-11-353 | 2 | Competition part. Heavy-duty spring provides increased pressure |
| SPRING – OIL SEAL REAR OUTER | 4352-11-363 | 2 | Competition part. Heavy-duty spring provides increased pressure |
| ENGINE GASKET SET | N231-89-100A | 1 | 84-85 set. Least expensive. works for any 12A if intake and exhaust manifold gaskets don’t matter. |
| MAIN SEAL, FRONT | 0820-10-605 | 1 | |
| MAIN SEAL, REAR | 1668-10-556A | 1 | |
| PILOT BEARING | N326-11-D03 | 1 | |
| PILOT BEARING SEAL | 1881-11-404A | 1 | |
| OPTIONAL INSTALLS | |||
| DESCRIPTION | PART NUMBER | QTY | NOTES |
| APEX SEAL – CARBON | 4352-11-301 | 6 | |
| APEX SEAL SPRING – FOR CARBON | 4352-11-304 | 6 | For use only with Carbon Apex Seal |
| APEX SEAL – CERAMIC 1PC | 0000-01-9101 | 2 | Comes with precut dual apex seal springs. 3 per box |
| APEX SEAL – CERAMIC 2PC | 0000-01-9111 | 2 | Comes with precut dual apex seal springs. 3 per box |
| CORNER SEAL SPRING – STOCK 12A | 1202-11-323A | 12 | Wire type. Use only if stock springs are required by class. Normally the washer type, NF01-11-C24, listed above will retain strength better under high temperatures. |
| ROTOR BEARINGS – STOCK | 1011-11-111 | 2 | STOCK |
| ROTOR BEARINGS – COMPETITION | 4801-11-111 | 2 | Competition bearings have 0.01 inch deeper oil groove and provide 0.0005 inch more clearance than stock bearings. Thinner overlay material improves bearing service life. |
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| MAIN BEARINGS – STOCK | 0820-10-502B | 2 | STOCK |
| MAIN BEARING – COMPETITION REAR | 4801-10-502 | 1 | Use in place of stock rear bearing. 3-window type. Recommended for any engine used at 8000 rpm and above. Increases oil flow to the inside of eccentric shaft and to rotors. |
| ECCENTRIC SHAFT | N201-11-400 | 1 | DISCONTINUED – LOW SUPPLY |
| ROTOR HOUSING FRONT AND REAR | N201-10-100 | 2 | 1976-83 (STOCK 81-83) |
| ROTOR HOUSING FRONT AND REAR | N249-10-100 | 2 | 1984-84 STOCK |
| ROTOR HOUSING FRONT | N210-10-100 | 1 | Japanese stock housing with largest of all exhaust ports. Requires least amount of exhaust port grinding for porting. |
| ROTOR HOUSING REAR | N210-10-150 | 1 | Japanese stock housing with largest of all exhaust ports. Requires least amount of exhaust port grinding for porting. |
| ROTOR HOUSING FRONT AND REAR | NLA | 2 | Factory Competition Peripheral Port – NO LONGER AVAILABLE |
| Use pdf catalogs online to search for intermediate housings. | |||