Views: 0 Author: Site Editor Publish Time: 2026-10-28 Origin: Site
The marine exhaust manifold is a core high-temperature component of the shipboard diesel engine exhaust system. Mounted tightly on the cylinder head, it collects high-temperature exhaust gas discharged from each combustion cylinder and converges the gas flow smoothly towards turbochargers, exhaust boilers or after-treatment units. Unlike automotive exhaust manifolds, marine versions work in an extremely tough environment with constant vibration, alternating temperature cycles, humid salty marine atmosphere and continuous heavy-load operation during long voyages. Even minor leakage or cracking of the manifold will lead to power drop, fuel overconsumption, abnormal noise, turbo damage and unexpected vessel downtime, which may cause huge losses for ship owners and shipping operators. Our factory specializes in custom casting marine exhaust manifolds made of Si-Mo ductile iron, offering both sample supply and mass production for various marine diesel engines.
We adopt silicon‑molybdenum ductile cast iron (Si-Mo ductile iron) as the primary material for marine exhaust manifolds, which is the preferred alloy material for high-temperature exhaust castings in marine industry. By adding silicon and molybdenum into nodular cast iron, this material obtains outstanding high-temperature oxidation resistance, thermal fatigue resistance and lasting high-temperature strength. The spherical graphite structure inside can effectively restrain crack propagation under repeated heating and cooling cycles. It keeps stable mechanical performance under long-term working temperature up to 750–850°C, resisting thermal deformation, surface scaling and corrosive attack from exhaust condensate and salty humid air onboard. Compared with ordinary gray cast iron, Si-Mo ductile iron greatly extends service life and reduces the risk of thermal cracking, which is critical for marine equipment requiring high reliability.
Our marine exhaust manifolds are produced with strictly controlled sand casting workflow, supporting both one-time tooling for small sample orders and permanent tooling for bulk serial production. The whole process covers pattern design, molding, melting and pouring, shakeout, cleaning, stress-relief annealing heat treatment, CNC precision machining and multi-item inspection.
For permanent tooling, the full set includes base plate, cold box and sand flask. All flange surfaces, bolt holes and connecting ports are machined to tight tolerance to guarantee perfect sealing after assembly. Stress-relief annealing is mandatory for every casting to eliminate internal residual casting stress, so the manifold will not warp or crack after being heated repeatedly on board. After machining, each manifold will go through visual inspection, dimension checking and air tightness leakage test before delivery. We also accept reverse development according to customer samples, 2D drawings or 3D CAD files. Our engineers will verify all technical data and runner structure, and perform flow optimization to reduce exhaust backpressure before tooling fabrication.
Internal runner geometry is optimized by fluid flow simulation. Smooth transition curves inside runners reduce exhaust resistance and backpressure, helping the diesel engine discharge waste gas efficiently, improve combustion efficiency and save fuel consumption. Reinforcement ribs are arranged on high-stress zones to enhance structural rigidity. All flange layouts, hole spacing and installation dimensions follow OEM specifications, making our castings direct-fit replacement parts without modification during installation.
We can produce standard single-wall manifolds and water-jacketed cooling type manifolds according to engine requirements. The water-jacketed structure separates high-temperature exhaust gas from cooling seawater, lowering surface temperature of the manifold, protecting surrounding pipelines and cables in the narrow engine room and lowering fire risk onboard.
Our cast marine exhaust manifolds fit a wide range of marine diesel engines, including auxiliary engines on cargo ships, fishing vessels, workboats, yachts and offshore equipment power units. We supply spare parts for shipyards, marine repair workshops, marine spare parts distributors and engine remanufacturing companies. We support small-batch sample orders of 2 pcs first, followed by follow-up mass orders such as 10 pcs and more. Better unit price discounts will be offered for larger production batches.
All quotations are EXW factory price, excluding VAT, freight and export formalities.
Tooling: Permanent tooling cost requires full payment after order confirmation. One-time tooling can be applied for small sample batches to save tooling investment for customers.
Casting product payment: 50% deposit in advance, and the balance shall be settled before shipment.
Lead time: 55 working days upon receipt of deposit. This lead time only counts the production cycle, excluding sea or land transit time.
We keep full batch records and inspection certificates for traceability. Material test reports, dimension reports and inspection documents can be provided together with goods. Our technical team provides continuous support from drawing confirmation, sample trial production to after-sales installation guidance. Whether you need OEM replacement parts or customized manifolds for special marine engine projects, we can convert your technical requirements into qualified castings.
With stable casting quality, flexible sample and mass delivery scheme, we aim to be your reliable long-term supplier of marine exhaust manifold castings. Welcome to send us OE numbers, samples, 3D models or engineering drawings for quotation and sample development.
