Baldwin B31 vs Champ PH3506: Oil Filter Compatibility
Compare Baldwin B31 and Champ PH3506 oil filters by compatibility, dimensions, thread size, gasket fit, bypass valve, anti-drainback valve status, and match confidence. Use this comparison as a fitment review, not as an automatic substitution guarantee. Both use a 13/16-16 thread.
Quick verdict
Both use a 13/16-16 thread.
- Thread size is the first hard-fit check for any comparison of spin-on filters.
- Gasket OD and gasket ID are the most important seal-related dimensions.
- Height differences can matter for clearance even when thread and gasket fit appear close.
- Bypass and anti-drainback differences may be important, depending on the application.
Baldwin B31 and Champ PH3506 specifications
How matching is scored| Specification | Baldwin B31 | Champ PH3506 |
|---|---|---|
| Thread size | 13/16-16 | 13/16-16 |
| Gasket OD | 69.9 mm | 70.4 mm |
| Gasket ID | 60.9 mm | 62.2 mm |
| Can OD | 76.2 mm | 77.47 mm |
| Height | 88.9 mm | 88.65 mm |
| Internal bypass valve | No | No |
| Bypass PSID | Not applicable | Not applicable |
| Anti-drainback valve | Yes | Yes |
What matters in this specific comparison
Thread size matches: both are 13/16-16.
Gasket OD differs by 0.5 mm (Baldwin B31: 69.9 mm, Champ PH3506: 70.4 mm).
Gasket ID differs by 1.3 mm (Baldwin B31: 60.9 mm, Champ PH3506: 62.2 mm).
Baldwin B31 is 0.2 mm taller (Baldwin B31: 88.9 mm, Champ PH3506: 88.65 mm) -- check clearance before substituting.
Can OD differs by 1.3 mm (Baldwin B31: 76.2 mm, Champ PH3506: 77.47 mm).
Open related filters
Before substituting, verify thread fit, gasket sealing dimensions, height clearance, bypass behavior, and anti-drainback requirements for your specific application.