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Understanding SAE Bellhousing and Flywheel Measurements

SAE Housing & Flywheel Dimensions

Below are listed standard Society of Automotive Engineers (SAE) adaptation 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:

Flywheel Measurements

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 adaptations for the engine housing and for the engine flywheel, i.e.: SAE#1 Flywheel Housing with SAE#14 Flywheel.

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

Dimensions in inches (millimeters)


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

Dimensions in inches (millimeters)

BellHousingMesurement Mar2011

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