The Muffler,exhaust, cataloged under National Stock Number 2990-00-038-4341, is classified within Federal Supply Class 2990 (Miscellaneous Engine Accessories, Nonaircraft) of the Engine Accessories group. Government technical data includes 19 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 2990-00-038-4341 |
| Item Name | Muffler,exhaust |
| FSC / FSG | 2990 / 29 — Miscellaneous Engine Accessories, Nonaircraft |
| Status | ACTIVE |
| Operating Position | HORIZONTAL |
| Inlet Outside Diameter | 1.875 INCHES NOMINAL SECOND INLET IN |
| Inlet Outside Diameter | 3.750 INCHES NOMINAL FIRST INLET IN |
| Inlet Location | LOCATED ON SIDE OF BODY CENTERED 3-5/8 IN. FROM OUTLET END OF BODY,ON SIDE OF BODY CENTERED 9-3/8 IN. FROM OUTLET END OF BODY,ON SIDE OF BODY CENTERED 15-1/8 IN. FROM OUTLET END OF BODY AND ON SIDE OF BODY CENTERED 20-7/8 IN. FROM OUTLET END OF BODY IN |
| Design Type | DRY |
| Overall Diameter | 8.000 INCHES NOMINAL IN |
| Center to Center Distance Between Mounting Holes | 5-3/4 IN. C TO C DISTANCE BETWEEN BOLT HOLES SINGLE INLET IN |
| Outlet Inside Diameter | 3.750 INCHES NOMINAL FIRST OUTLET IN |
| Inlet Projection Length | 4.000 INCHES NOMINAL ALL INLETS IN |
| Baffle Quantity | 1 |
| Inlet Flange Mounting Hole Diameter | 0.500 INCHES NOMINAL SINGLE INLET IN |
| Muffler Design | BAFFLE |
| Outlet Outside Diameter | 4.000 INCHES NOMINAL FIRST OUTLET IN |
| Unable to Decode | UNABLE TO DECODE |
| Inlet Inside Diameter | 1.625 INCHES NOMINAL SECOND INLET IN |
| Inlet Inside Diameter | 3.500 INCHES NOMINAL FIRST INLET IN |
| Material | STEEL CORROSION RESISTING LOCATION NOT OTHERWISE SPECIFIED |
| Outlet Projection Length | 2.000 INCHES NOMINAL FIRST OUTLET IN |
| Outlet Location | LOCATED 9/16 IN. C TO C FROM HORIZONTAL CENTER LINE IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 1556 | 3/2 Design control — primary reference U.S. Government activity |
NSN 2990-00-038-4341 is a Muffler,exhaust, classified under FSC 2990, Miscellaneous Engine Accessories, Nonaircraft. Status: active.
Key specifications for 2990-00-038-4341: Operating Position: HORIZONTAL; Inlet Outside Diameter: 1.875 INCHES NOMINAL SECOND INLET IN; Inlet Outside Diameter: 3.750 INCHES NOMINAL FIRST INLET IN; Inlet Location: LOCATED ON SIDE OF BODY CENTERED 3-5/8 IN. FROM OUTLET END OF BODY,ON SIDE OF BODY CENTERED 9-3/8 IN. FROM OUTLET END OF BODY,ON SIDE OF BODY CENTERED 15-1/8 IN. FROM OUTLET END OF BODY AND ON SIDE OF BODY CENTERED 20-7/8 IN. FROM OUTLET END OF BODY IN. 19 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.