Also available in 304 Stainless: 1.500" | 1.750" | 2.000" | 2.250" | 2.375" | 2.500" | 3.000" | 3.500" | 5.000"
All Flex Bellows sizes
304 STAINLESS FLEX BELLOWS WITH SMOOTH-BORE INNER LINER — ABSORBS THERMAL EXPANSION IN TURBO MANIFOLDS AND HOT-SIDE PLUMBING
This 4.000" ID flex bellows with a 4.000" overall length is built to take up the growth of hot exhaust tubing, with up to 0.523" (13.29 mm) of compression / extension. Both ends are a slip-fit for 4.000" OD tube, so the tube slides into the bellows for easy alignment before welding.
Turbo manifolds and hot-side tubing grow as they heat up and shrink as they cool, every time you drive. If that growth has nowhere to go, it pushes on the turbo and cracks welds. A bellows gives the tube room to compress and extend, and the solid inner liner protects the bellows and keeps flow smooth, so it can be used before the turbo.
FEATURES
- 100% 304 stainless construction
- 2-ply bellows
- Smooth-bore, directional inner liner
- Slip-fit inlet and outlet (welding required)
- Bellows OD: 4.921" (125 mm)
- Pressure tested: 145 psi at 68°F and 72.5 psi at 842°F
- Helium leak tested before shipment
Full specifications are listed in the spec table at the bottom of this page. Nominal dimensions; material tolerances apply. A dimensional drawing is included in the image gallery.
WHERE TO USE IT
- Turbo manifolds, often welded in between runners or before the collector
- Wastegate and dump tubes
- Long hot-side runs and other locations that see repeated heat cycles
BELLOWS OR FLEX COUPLING? A bellows is built for compression and extension from heat, with very little bending (0.7° max for this size). If you need to isolate engine movement and vibration, a braided flex coupling allows more angular movement, but its interlock liner is not for use before the turbo.
INSTALLATION TIPS
- The inner liner is directional and must be installed in the direction of exhaust flow.
- Don't twist the bellows, and don't use it to make up for misaligned tubes.
- Install it at its free length so it has its full compression and extension available once hot.
- Back-purge when welding, and keep weld spatter off the convolutions.
MATCHING PARTS
Pair this bellows with our 304 stainless tube, 304 mandrel bends and 304 V-band clamps and flanges. For parts that live at sustained high heat, see 304 vs. 321 Stainless. Questions about a specific part? Email us at support@aceraceparts.com.
