Vetus M4.35S Saildrive Marine Diesel Engine Package

Description

An integrated SeaProp 60 lower unit and 1.8L displacement distinguish the Vetus M4.35S Saildrive Marine Diesel Engine. This 4-Cylinder package outputs 29.5BHP continuous power at 2,800 RPM for offshore sailing yachts. Vessel owners must follow seven-year hull diaphragm replacement cycles and clean marine growth from the saildrive raw water ingestion slots on strict seasonal schedules.

The structural base combines an ASTM gray cast iron monobloc with parent bores and a rigid overhead-valve cylinder head. Electrical architecture features a 12V negative ground system powered by a 1.7 kW starter motor and a 110A marine alternator. Dry mass spans 309 lbs excluding the saildrive lower leg. The engine mounting stance occupies 26.8in of length, 18.9in of width, and 22.6in of height, holding 1.27 US gal of oil.

Key Features of Vetus M4.35S

Modern cruising sailors buy Vetus M4.35S saildrive marine diesel engines to secure low-drag auxiliary propulsion without traditional shaft vibration. The integrated package represents an ideal sailing yacht auxiliary engine repower option for monohulls and catamarans up to 38ft.

• SeaProp 60 saildrive leg eliminates shaft angle vibration and packing gland drip maintenance.
• Naturally aspirated 4-Cylinder block generates smooth rotational balance across the full power band.
• Cast aluminum acoustic cover isolates mechanical valve train noise from living areas.
• Saildrive leg raw water ingestion feeds cooling fluid to the tubular heat exchanger core.
• High-capacity 110A marine alternator restores domestic battery banks during brief motoring runs.
• Dedicated saildrive foundation bed cushions mechanical shock loads from the hull laminate.
• Mechanical multi-plunger fuel injection pump ensures consistent cylinder firing across changing sea states.

Saildrive Dynamometer Testing Thermal Limits

Dynamometer load verification proves 29.5BHP continuous output and 58 ft-lbs of shaft torque at 2,800 RPM, peaking at 33.0BHP at 3,000 RPM. Raw seawater ingestion through the saildrive leg maintains tubular heat exchanger coolant temperatures stabilized at 178°F under continuous full-load motoring. Exhaust pyrometer temperatures remain under 920°F ahead of the water-injected exhaust mixer. Main journal oil pressure registers 50 PSI at cruising RPM, while crankshaft journal runout measures within 0.0004in TIR across all bearing contact surfaces.

Field Usability Protocols Installation Boundaries

Single-lever sail control levers require 4 lbs of smooth hand effort to advance the mechanical governor across the operating band. This saildrive powertrain is not built for heavy commercial workboats, steel canal narrowboats, or high-speed planing hulls. Never select this sailing yacht auxiliary engine repower package for craft without a reinforced GRP saildrive foundation bed or hulls requiring traditional shaft logs.

• Change engine oil and replace the spin-on lube filter every 150 operating hours.
• Inspect lower saildrive gear lube and replace zinc anodes every 12 months.
• Check mechanical overhead valve lash clearances to 0.010in cold every 500 operating hours.

Factory Warranty Marine Crate Manifest

Vetus backs this complete saildrive package with a 5-Year leisure and 3-Year commercial marine manufacturer warranty. The shipment crate includes the bobtail diesel engine, SeaProp 60 saildrive lower unit, mounting bed frame, 12V 1.7 kW starter, 110A alternator, wiring harness, instrument display panel, and factory maintenance documentation.