HYDM440M Hydraulic Motor | 4.40 cid Marzocchi

HYDM440M Hydraulic Motor | 4.40 cid Marzocchi | Big-Displacement Alternate Frame

HYDM440M is the second Marzocchi answer in the 40-horsepower band: a 4.40 in³ (72cc) gear motor standing beside the line’s 4.33 cid unit with functionally identical arithmetic — roughly 44 horsepower of pump drive at 1450 RPM on about 27.6 GPM of oil — and a different build series behind it. At 1.6% apart, the two displacements do not compete on performance; what separates them in practice is the hardware around the gears: port style, mount pattern, shaft details, and frame dimensions differ between Marzocchi’s series, and the correct choice for a given build is the one whose interfaces match the pump, the coupling, and the plumbing already on the table. WSHPWR stocks both precisely so that match is a selection, not a compromise.

The duty band is the top of conventional single-gear-motor territory: RTX-class 300-bar platforms at their 45 HP published demand, the strongest XW and SXW washdown duties, and production systems whose oil budget runs to the high twenties of GPM all shift. Wherever the 40-plus horsepower class is specified and the alternate frame’s interfaces fit the build better, the HYDM440M is the answer.

HYDM440M Specifications

• SKU: HYDM440M
• Manufacturer: Marzocchi (Bologna, Italy)
• Type: External gear hydraulic motor — heavy-frame class, alternate series
• Displacement: 4.40 in³ (72cc) per revolution
• Oil Flow for Pump-Speed Drive: Approximately 27.6 GPM at 1450 RPM
• Pressure and Speed Ratings: Marzocchi heavy gear class — confirm the series build sheet with WSHPWR for your duty point
• Drive Duty: Approximately 44 HP of pump drive at 1450 RPM
• Shaft and Ports: Series-specific — confirmed at order against your pump, coupling, and plumbing interfaces

Sizing the HYDM440M

The selection line — RPM ≈ 231 × hydraulic GPM ÷ 4.40 — lands the pump at 1450 RPM on roughly 27.6 GPM of oil, and torque follows displacement at T ≈ 4.40 × ΔPSI ÷ 6.283: around 160 lb-ft at heavy gear-class continuous pressures, carrying the ~44 HP tier with the 45 HP RTX 60.300-class duty essentially at rating. Supply is engineered-system territory without exception — dedicated power units or truck hydraulics with reservoir volume at 2–3× total flow, 10–25 micron return filtration with honest beta ratings, and cooling designed for equilibrium at continuous load. Send WSHPWR the circuit’s flow, pressure, and target pump; the pairing, the series selection, and the build sheet all get confirmed before anything ships.

Choosing Between the 4.33 and 4.40

When two motors deliver the same duty, the decision moves to everything else — and that is the honest guide here. The 4.33 cid unit carries SAE Code 61 flange ports and the ARNA-published rating set; the HYDM440M’s series presents its own port, shaft, and mount configuration. Match against three questions: which port style does your plumbing already speak (flange kits on the shelf, or O-ring boss)? Which shaft does your coupling hub fit without an adapter? Which frame lands on your base’s pattern? Answer those and the selection makes itself — and where both fit, availability and price break the tie. WSHPWR walks this comparison daily; one call with your build’s interfaces settles it.

Completing the Build

The HYDM440M lives in the heavy mounting world — the adjustable HYDBK3 base’s long-travel slides and drill-to-fit patterns accommodate alternate-series frames by design, and the HYDBK4-class cast-iron architecture serves where the interfaces align — with coupling and mount confirmed against your pump at order. As a repower, it is frequently the exact-match restoration for fielded systems built on this series originally: confirm shaft, mount, and ports against the installation, swap the component, resume production. WSHPWR verifies the complete drive on every heavy-class order.

Installation & Operation Notes

Confirm rotation direction against your pump before plumbing — at this torque a backward start is an expensive mistake. Torque port connections to their specification (flange bolts evenly with O-rings seated, or boss fittings to spec, per the series), set the circuit relief within the motor’s rating, route the return generously to tank through 10–25 micron filtration, and plumb any case drain above reservoir oil level. Engineer cooling for equilibrium at 44 horsepower of continuous drive, mount to structure worthy of the assembly’s mass, and verify pump speed at commissioning by the flow-÷-displacement math or a phototach — the pump’s rated RPM governs the ceiling, always.

Quality Assurance & Maintenance

Every HYDM440M carries Marzocchi’s factory testing and ships only after WSHPWR confirms the series, the interfaces, and the pairing against your stated pump and circuit. The ongoing program is gear-minimal at full scale: clean, filtered oil, a correct relief, periodic inspection of port joints, hose ends, and drain lines — no internal service schedule. Run inside its margins, it outlasts the wet ends it drives.

HYDM440M Key Features & Applications

• 4.40 cid Marzocchi — the alternate-series answer in the 40-plus horsepower band.
• ~44 HP of pump drive at 1450 RPM on ~27.6 GPM of oil.
• Selection by interface: port style, shaft, and mount decide between the 4.33 and 4.40 — not performance.
• Served by the adjustable HYDBK3 architecture’s drill-to-fit design; series confirmed at order.
• The exact-match repower for fielded systems originally built on this series.
• Ideal for RTX-class 300-bar pump drives, the strongest XW/SXW duties, production systems with high-twenties GPM oil budgets, and builds whose plumbing picks the frame.