Bulletin #13
Determining SAE Housing/Flywheel Dimensions for Generators
Marathon Electric manufactures generators with standard Society of Automotive Engineers (SAE) adaption configurations. This configuration allows easy coupling to most diesel and gas engines which follow the same SAE standards. The following graphic shows the typical configuration and their respective SAE denomination:
To determine the SAE adaption in your specific application, simply match dimensions XD, XB, XE, XF and XG to arrive at a combination of SAE adaptions for the engine housing and for the engine flywheel, i.e.: SAE#1 Flywheel Housing with SAE#14 Flywheel.
DIMENSIONS in Inches or (millimeters):
Engine Flywheel Housing Dimensions
| SAE No. | XD | XB | Tapped Holes Qty. | Size |
| 00 | 31.000 (787) | 33.50 (851) | 16 | 1/2-13 |
| 0 | 25.500 (678) | 26.75 (679) | 16 | 1/2-13 |
| 1/2 | 23.000 (584) | 24.38 (619) | 12 | 1/2-13 |
| 1 | 20.125 (511) | 20.88 (530) | 12 | 7/16-14 |
| 2 | 17.652 (448) | 18.38 (467) | 12 | 3/8-16 |
| 3 | 16.125 (410) | 16.88 (429) | 12 | 3/8-16 |
| 4 | 14.250 (362) | 15.00 (381) | 12 | 3/8-16 |
| 5 | 12.375 (314) | 13.12 (333) | 8 | 3/8-16 |
| 6 | 10.500 (267) | 11.25 (283) | 8 | 3/8-16 |
Engine Flywheel Dimensions
| SAE No. | XE | XF | XG | Tapped Holes Qty. | Size |
| 21 | 26.500 (673) | 25.25 (641) | 0 (0) | 12 | 5/8-11 |
| 18 | 22.500 (572) | 21.38 (543) | .62 (16) | 6 | 5/8-11 |
| 14 | 18.375 (467) | 17.25 (438) | 1.00 (25) | 8 | 1/2-13 |
| 11-1/2 | 13.875 (352) | 13.12 (333) | 1.56 (40) | 8 | 3/8-16 |
| 10 | 12.375 (314) | 11.62 (295) | 2.12 (54) | 8 | 3/8-16 |
| 8 | 10.375 (264) | 9.62 (244) | 2.44 (62) | 6 | 3/8-16 |
| 7-1/2 | 9.500 (241) | 8.75 (222) | 1.19 (30) | 8 | 5/16-18 |
| 6-1/2 | 8.500 (210) | 7.88 (200) | 1.19 (30) | 6 | 5/16-18 |
| Delco 17.75 | 17.755 (451) | 15.50 (394) | .72 (18) | 8 | 5/8-11 |
| Delco 15.50 | 15.500 (394) | 13.88 (353) | .72 (18) | 8 | 5/8-11 |
| Delco 12.75 | 12.750 (324) | 11.00 (279) | 0 (0) | 4 | 1/2-13 |
Davidson Sales Company represents Marathon Electric Mfg. Co., a leader in design and manufacture of electric generators for industrial power generation. If you have any questions about this product line, contact us.
