Model: 4M10G70
Part Number: 1004877734
Brands: Baudouin
Engine Model: 4M10G70
Engine Type: Marine and industrial diesel
Scope of application: marine propulsion, marine auxiliary, generator sets
The 4M10G70 is the lowest-rated engine in the Baudouin 4M10G family, widely used for auxiliary duty driving generators on working boats. Part 1004877734 is the piston for this rating, with a cooling gallery fed by an oil jet under the crown and ring grooves machined for the G70 ring set.
Although the load is lower than on a G110, auxiliary engines often run at a near-constant setting for many hours, and the piston sees steady heat rather than varying load. That makes cooling and oil flow the deciding factors in piston life.
Pistons differ between 4M10G ratings in bowl shape, compression height and compression ratio. Fitting a G88 or G110 piston to a G70 changes combustion and produces smoke and high exhaust temperature, and injector adjustment cannot correct it.
Auxiliary engines are often serviced less attentively than propulsion engines because they are less visible in daily operation. That is precisely why injector faults and cooling problems go unnoticed until a piston fails.
Check every cooling jet for flow and confirm the correct nozzle before fitting new pistons. A blocked jet overheats the crown. Check the pin bore with the small end bush; if the pin rocks visibly, the piston is worn and replacement is the only reliable repair.
Keep pistons in their packaging until the block is ready. Store them upright, not stacked on crowns, and keep the pin and circlips with the piston they belong to. Mixing pins between pistons causes unexplained noise after a rebuild.
Run the rebuilt engine at varying load rather than holding a fixed generator setting. Increase load gradually over the first hours and change oil early. Holding rated load immediately glazes the bores.
Poor fuel and neglected injectors are the two most common causes of piston damage on auxiliary engines. Keep fuel filters changed and have injectors tested at the recommended hours. A leaking injector both dilutes the oil and washes the bore.
Correct injection timing, clean fuel and adequate cooling keep pistons alive. Keep the cooling jets clear and maintain the heat exchanger so coolant temperature stays in range.
Auxiliary engines are often treated as secondary equipment, yet they are what keeps the lights and refrigeration running. Because they are less visible than the main engine, injector faults and cooling problems are noticed later, and by then the piston has already been through hundreds of hours of over-fuelling or overheating.
Give the auxiliary engine the same service schedule as the main engine. Check coolant level and condition at every watch, record running hours and have the injectors tested at the recommended interval. That discipline costs very little and prevents exactly the failures this piston page describes.
Measure clearance at the skirt at right angles to the pin with the piston at room temperature. Too little seizes the piston when hot; too much rattles at cold start. Both are avoidable by measuring rather than trusting that the parts are matched.
A genset engine runs at a fixed speed, so the piston sees a steady heat input rather than the cycling of a road engine. That steady state is why cooling jet flow and coolant temperature matter more than transient behaviour, and why a partially blocked jet shows up as crown damage rather than as an obvious overheat.
Check coolant temperature against the alarm set point at full load. If the engine runs close to the alarm on a cool day, it will exceed it on a hot one, and the pistons pay the price.
No. Each rating uses its own piston.
It is supplied bare by default. Complete assemblies are available.
Yes, within one engine.
Over-fuelling, incorrect timing or a blocked cooling jet.
Browse the Baudouin piston and components category, and pair the piston with the 4M10G70 overhaul kit 1000156637 or the 4M10G70 cylinder head 1004713403.
Baudouin 4M10G70 Piston (1004877734). This piston carries the combustion load and forms half of the combustion chamber. Its crown profile is matched to the rating, not just to the bore diameter.
Confirm the piston number and the engine plate together. Pistons are specified by rating, so the engine model alone does not identify the right part.
Numbers beginning 1004 are numeric-series numbers used on later WP7 and WP8 production, where mounting detail changed without a change of nominal type. On this engine, confirm the 4M10G70 application against the engine plate before ordering.
Check piston-to-bore clearance and ring end gaps in the actual bore. Measuring in a spare liner gives a false reading and is a common cause of oil use after a rebuild.
Ordering note. Photographs of the actual unit can be sent before dispatch on request. That is the cheapest way to avoid a return when a casting revision is in doubt.
Related reading: Piston Ring Selection: Gap, Tension and Bore Condition
| We Are 30 Years Diesel Engine Parts Supplier | |
| Brand | EPID |
| Warranty | 12 Months |
| Condition | 100%New |
| More Models | Weichai: 4M10G70, and other Weichai series. |
| Shipping | By sea / air / express (DHL, FEDEX, TNT, UPS, EMS) |
| Packing | Standard exporting packing or as required |
| Payment Term | L/C, T/T, Western Union, Trade Assurance |
| Delivery Time | 3-7 days (depend on order) |
| Selling Point | 1. On-time Delivery 2. Genuine Quality Assurance 3. Professional Supplier |
Auxiliary engines are often serviced less attentively than propulsion engines because they are less visible in daily operation. That is precisely why injector faults and cooling problems go unnoticed until a piston fails.
Check every cooling jet for flow and confirm the correct nozzle before fitting new pistons. A blocked jet overheats the crown. Check the pin bore with the small end bush; if the pin rocks visibly, the piston is worn and replacement is the only reliable repair.
Keep pistons in their packaging until the block is ready. Store them upright, not stacked on crowns, and keep the pin and circlips with the piston they belong to. Mixing pins between pistons causes unexplained noise after a rebuild.
Run the rebuilt engine at varying load rather than holding a fixed generator setting. Increase load gradually over the first hours and change oil early. Holding rated load immediately glazes the bores.
Poor fuel and neglected injectors are the two most common causes of piston damage on auxiliary engines. Keep fuel filters changed and have injectors tested at the recommended hours. A leaking injector both dilutes the oil and washes the bore.
Correct injection timing, clean fuel and adequate cooling keep pistons alive. Keep the cooling jets clear and maintain the heat exchanger so coolant temperature stays in range.
Auxiliary engines are often treated as secondary equipment, yet they are what keeps the lights and refrigeration running. Because they are less visible than the main engine, injector faults and cooling problems are noticed later, and by then the piston has already been through hundreds of hours of over-fuelling or overheating.
Give the auxiliary engine the same service schedule as the main engine. Check coolant level and condition at every watch, record running hours and have the injectors tested at the recommended interval. That discipline costs very little and prevents exactly the failures this piston page describes.
Measure clearance at the skirt at right angles to the pin with the piston at room temperature. Too little seizes the piston when hot; too much rattles at cold start. Both are avoidable by measuring rather than trusting that the parts are matched.
A genset engine runs at a fixed speed, so the piston sees a steady heat input rather than the cycling of a road engine. That steady state is why cooling jet flow and coolant temperature matter more than transient behaviour, and why a partially blocked jet shows up as crown damage rather than as an obvious overheat.
Check coolant temperature against the alarm set point at full load. If the engine runs close to the alarm on a cool day, it will exceed it on a hot one, and the pistons pay the price.
Browse the Baudouin piston and components category, and pair the piston with the 4M10G70 overhaul kit 1000156637 or the 4M10G70 cylinder head 1004713403.
No. Each rating uses its own piston.
It is supplied bare by default. Complete assemblies are available.
Yes, within one engine.
Over-fuelling, incorrect timing or a blocked cooling jet.
EPID supplies diesel engine parts for Weichai, Baudouin, Yuchai, Caterpillar, Sinotruk, FAW Xichai and Cummins engines. Every order is checked against the original part number before packing, and our team can identify a part from a photo of the engine plate. Ask for a quotation with your model and quantity and we will reply within one working day.
