Monohull · 7 documented fitments
Propeller upgrade for the Rival 38 — what fits, what changes.
Drawn from 7 documented Rival 38 fitments: the common setup is an Autoprop H5 around 443 mm behind the Bukh DV36. Typical result: 300–400 fewer RPM at cruise and up to 20% fuel saved over fixed pitch.
The fitment card
Documented engine variants & what they wear
Aggregated from 7 real installations — not a size chart, a service record.
| Engine | Power / max RPM | Drive | Typical ratio | Documented propeller | Rotation | Records |
|---|---|---|---|---|---|---|
| Bukh DV36 | 36 hp / 3600 | Shaft | 3:1 | Autoprop H5 · 443 mm | Right-hand | 2 |
| Thornycroft T98 | 35 hp / 3000 | Shaft | 1.79:1 | Sized per boat | Right-hand | 1 |
| Perkins 4108 | 38 hp / 3000 | Shaft | 1.79:1 | Autoprop H5 | Right-hand | 1 |
| Bukh | 36 hp / 3600 | Shaft | 3:1 | Autoprop H5 | Right-hand | 1 |
| Ford XLD 41.8 | 53 hp / 3600 | Shaft | 2.63:1 | Autoprop H5 | Right-hand | 1 |
| Yanmar 3HM35 | 35 hp / 3600 | Shaft | 2.83:1 | Autoprop H5 | Right-hand | 1 |
Indicative only — gearboxes and apertures vary between years and repowers, which is why every supplied propeller is verified against your boat first. Data current as of 2026.
Your numbers
What the change feels like on a Rival 38
Indicative curves for this size of boat — drag the cruise line. The independent-test pattern: the same six knots on several hundred fewer RPM, with the fuel flow following.
Worth knowing
Considerations for the Rival 38
- 6 engine variants are documented for this model — repowers included. Sizing follows your engine and ratio, not the year in the brochure.
- Tip clearance rules the maximum diameter — roughly 10–15% of prop diameter to the hull. The Builder asks; we verify before supply.
Rival 38 propeller questions
What size propeller does a Rival 38 take?
Documented Rival 38 installations most commonly run an Autoprop H5 around 443 mm, matched to the Bukh DV36 on a shaft drive. Exact size depends on your engine, gearbox ratio and aperture — every recommendation is verified by an engineer before supply.
How much fuel would a Rival 38 save with an Autoprop?
Typical savings over a fixed-pitch propeller are up to 20% at cruise (documented band 15–30%, honestly less if you already run a folding or feathering prop). Put your engine hours and diesel price into the fuel calculator for your own numbers — then the Builder for a verified recommendation.
My Rival 38 has a different engine than shown — does the data still help?
Yes. Repowers are common and the database usually holds several engine variants per model. The Builder starts from your actual engine and gearbox; the model records confirm diameters and clearances that are known to work on this hull.
Get the verified recommendation for your Rival 38
The Builder pre-fills from these 7 documented fitments — confirm your engine and gearbox, and an engineer replies within one business day.