OM606 D35 LA – 3.5-Litre Mercedes OM606 Engine Build

OM606 D35 LA – increased displacement, early torque delivery and mechanical diesel injection

The OM606 D35 LA is a specially developed high-performance diesel engine based on the proven Mercedes-Benz OM606 inline-six engine.

Developed by Einspritzpumpen Manufaktur NRW, the D35 LA concept increases the displacement of the standard 3.0-litre OM606 into the 3.5-litre class.

The objective of this engine concept is not simply to achieve the highest possible peak horsepower.

Our main focus is on:

• increased displacement

• very early torque delivery

• strong low- and mid-range performance

• high usable torque

• mechanical diesel injection

• individually matched turbocharger systems

• precisely machined engine components

• a complete engine concept matched to the intended application

Depending on engine configuration, injection system, turbocharger and intended use, engine specifications of up to approximately 750 hp and up to 1,450 Nm of torque can be realised.

The OM606 D35 LA is therefore particularly suitable for powerful Mercedes-Benz G-Class conversions, heavy vehicles, special-purpose vehicles, individual road projects and selected marine applications.

What is an OM606 D35 LA?

The OM606 D35 LA is not a factory-produced Mercedes-Benz engine designation.

Mercedes-Benz originally produced the OM606 as an approximately 3.0-litre six-cylinder diesel engine.

The designation OM606 D35 LA describes our extensively modified 3.5-litre development based on the Mercedes OM606 engine platform.

The engine is not converted to 3.5 litres by changing one single component.

Instead, the increased displacement is achieved through a coordinated combination of changes to the:

• cylinder bore

• crankshaft stroke

• pistons

• connecting rods

• rotating assembly

• cylinder block

• cylinder head

• fuel injection system

• turbocharger system

The result is a fundamentally different engine configuration from a standard OM606 D30 LA.

From OM606 D30 LA to OM606 D35 LA

The standard Mercedes OM606 engine has an approximate displacement of 2,996 cm³, an 87 mm cylinder bore and an 84 mm crankshaft stroke.

For our OM606 D35 LA engine concept, the engine is extensively modified to increase displacement into the 3.5-litre class.

The conversion includes, depending on the individual engine configuration:

• cylinder bore increased to 89 mm

• specially manufactured pistons

• increased crankshaft stroke

• specially designed shorter connecting rods

• modified rotating assembly geometry

• precision machining of the cylinder block

• cylinder head preparation

• reinforced and optimized valve train components

• individually configured mechanical diesel injection pump

• application-specific turbocharger configuration

Every component must work together as part of a complete system.

Simply installing larger pistons or increasing crankshaft stroke does not create a properly engineered 3.5-litre OM606.

OM606 D30 LA vs. OM606 D35 LA

SpecificationStandard OM606 D30 LAOM606 D35 LAEngine configurationInline six-cylinderInline six-cylinderCombustion systemIndirect injection dieselIndirect injection dieselDisplacementapprox. 3.0 litresapprox. 3.5 litresCylinder bore87 mm89 mmCrankshaft strokeStandardIncreasedPistonsStandard production pistonsSpecial pistonsConnecting rodsStandardSpecial reinforced designFuel injectionDepending on original versionIndividually configured mechanical injection systemTurbochargerStandard configurationApplication-specific configurationMain objectiveProduction vehicle operationHigh torque and individual performance characteristicsMaximum torqueDepending on standard versionup to approx. 1,450 Nm*

*Depending on engine configuration, fuel injection system, turbocharger, calibration and intended application.

89 mm Special Pistons

One of the fundamental modifications within the OM606 D35 LA concept is the increase in cylinder bore from the standard 87 mm to 89 mm.

Special pistons are used for this application.

Increasing cylinder diameter requires significantly more than simply fitting oversized pistons.

The cylinder block must be accurately measured and machined according to the actual piston dimensions and intended operating conditions.

Important factors include:

• cylinder geometry

• piston-to-cylinder clearance

• thermal expansion

• piston ring operation

• cylinder surface finish

• combustion loading

• mechanical loading

For this reason, cylinder machining is treated as part of the complete engine build rather than as an isolated operation.

Increased Crankshaft Stroke

In addition to the increased cylinder bore, the crankshaft stroke is increased compared with the standard Mercedes OM606 engine.

The combination of increased bore and increased stroke creates the displacement of the 3.5-litre OM606 D35 LA.

Increasing stroke has another important effect:

It contributes significantly to the desired torque characteristics of the engine.

Our D35 LA concept is designed to provide strong usable torque at relatively low engine speeds, rather than developing all of its performance only at high rpm.

This makes the engine particularly interesting for vehicles where acceleration, pulling power and drivability are more important than a single maximum horsepower figure.

Special Connecting Rods for the OM606 D35 LA

The modified crankshaft geometry requires connecting rods specifically matched to the D35 LA rotating assembly.

We use specially designed and reinforced connecting rods for this purpose.

Connecting rod geometry must match the complete combination of:

• crankshaft

• crankshaft stroke

• piston design

• piston pin location

• cylinder block geometry

• intended cylinder pressure

• engine speed

• performance target

The connecting rods used in the OM606 D35 LA are therefore not simply generic performance parts.

They form an integral part of the complete engine design.

Exact dimensions, geometry and proprietary engineering parameters of our components are part of our internal technical development and are not published.

Cylinder Block Machining

Increasing displacement to approximately 3.5 litres requires extensive precision machining.

Before and during the engine build, the cylinder block and relevant components are measured and inspected.

Depending on engine condition and specification, our machining work can include:

• dimensional inspection of the engine block

• cylinder measurement

• cylinder boring

• precision finishing of the cylinder bores

• honing

• deck surface machining

• inspection of relevant bearing locations

• dimensional control before assembly

• turning and milling operations

• component fitting and verification

Cylinder machining is performed according to the components actually used in the engine.

This is especially important with custom pistons and modified rotating assemblies.

Cylinder Geometry and Piston Clearance

Correct cylinder geometry is essential for a high-performance diesel engine.

The cylinder must not only have the correct nominal diameter.

It must also be evaluated for:

• roundness

• taper

• surface condition

• piston clearance

• piston ring operation

An incorrect piston-to-cylinder clearance can lead to serious engine problems.

Excessively tight clearance can create increased friction and thermal problems.

Excessive clearance can result in:

• increased oil consumption

• poor ring sealing

• piston noise

• reduced mechanical efficiency

Precision machining is therefore one of the foundations of the D35 LA engine build.

Cylinder Head and Valve Train

Increasing displacement, torque and cylinder pressure also increases the demands placed on the cylinder head.

Depending on the individual engine specification, the cylinder head is inspected and prepared accordingly.

Possible work can include:

• cylinder head inspection

• dimensional inspection

• resurfacing

• valve inspection

• valve seat machining

• valve guide inspection

• valve train inspection

• installation of appropriately specified components

The exhaust side of a high-performance diesel cylinder head is particularly important because of the thermal loads generated during operation.

Reinforced and Optimized Valves

For selected high-performance engine configurations, reinforced or optimized valve components can be used.

This is particularly relevant where significantly increased:

• exhaust gas temperature

• cylinder pressure

• air mass

• fuel delivery

• turbocharger pressure ratio

change the operating environment compared with a standard production engine.

The valve itself cannot be considered separately from the valve seat, guide and cylinder head.

Heat transfer between these components is essential to reliable operation.

Mechanical Injection Pump for the OM606 D35 LA

A high-performance diesel engine is only as good as its fuel injection system.

One of our major advantages is that engine building and mechanical diesel injection technology are combined within the same specialist workshop.

For suitable OM606 D35 LA projects, we build and calibrate mechanical Bosch inline injection pumps specifically for the engine configuration.

The injection system can be configured according to:

• engine displacement

• required horsepower

• required torque

• turbocharger configuration

• vehicle weight

• transmission

• axle ratio

• intended operating range

• throttle response

• maximum engine speed

• intended application

The objective is not simply to achieve the highest possible maximum fuel delivery.

The complete delivery characteristic of the injection pump must match the engine.

This includes how fuel delivery develops across the operating range.

Mechanical Diesel Injection – Engine and Pump as One System

The injection pump has a direct influence on:

• combustion pressure

• torque delivery

• exhaust gas temperature

• smoke behaviour

• turbocharger response

• engine speed characteristics

• overall drivability

For this reason, we do not treat the OM606 engine and its mechanical injection pump as two unrelated components.

The injection system is developed as part of the complete engine concept.

This is particularly important for high-torque engines where a poorly matched injection system can produce excessive thermal and mechanical loading even when maximum horsepower appears acceptable.

Turbocharger Matching – Torque Instead of Excessive Turbo Lag

The larger displacement of the OM606 D35 LA provides significant advantages when configuring the turbocharger system.

Our objective is to achieve a very early increase in boost pressure and strong torque delivery at low and medium engine speeds.

For us, turbocharger selection is not based on the principle:

“The larger the turbocharger, the better the engine.”

Instead, the turbocharger must be selected according to the complete operating concept.

Important parameters include:

• engine displacement

• desired airflow

• fuel delivery

• compressor characteristics

• turbine characteristics

• exhaust housing

• boost pressure

• exhaust back pressure

• engine operating range

• vehicle weight

• transmission ratios

• intended use

A heavy Mercedes G-Class requires a completely different torque characteristic from a lightweight competition vehicle.

For the OM606 D35 LA, usable torque and response are therefore major priorities.

Up to 1,450 Nm of Torque

Depending on the complete engine configuration, OM606 D35 LA engines can be built for performance levels of up to approximately 750 hp and up to 1,450 Nm of torque.

These figures do not represent a standard specification for every engine we build.

The appropriate power level depends on many factors, including:

• engine configuration

• turbocharger

• injection system

• cooling system

• lubrication

• transmission

• vehicle weight

• axle ratio

• maximum engine speed

• driving profile

• intended service life

• continuous or intermittent load

Not every vehicle needs 750 hp.

In many applications, a lower maximum horsepower level combined with a very strong and broad torque curve can create a much better vehicle.

This is especially true for heavy off-road vehicles, expedition vehicles and towing applications.

High Torque Instead of Peak Horsepower Only

Peak horsepower alone says relatively little about how an engine behaves in real-world operation.

For many vehicles, it is much more important to understand:

• when torque begins to increase

• how quickly boost pressure develops

• how much torque is available in the low rpm range

• how broad the useful power band is

• how the engine responds under load

The additional displacement of the OM606 D35 LA gives us a strong foundation for creating a diesel engine with substantial low- and mid-range performance.

The objective is a powerful engine that is usable in the vehicle, rather than one designed solely to produce a high figure on a dyno sheet.

OM606 D35 LA for Mercedes-Benz G-Class

One of the most interesting applications for our 3.5-litre OM606 concept is the Mercedes-Benz G-Class.

Possible applications include:

• Mercedes-Benz G-Class W460

• Mercedes-Benz G-Class W461

• Mercedes-Benz G-Class W463

• expedition vehicles

• off-road vehicles

• heavy travel vehicles

• towing vehicles

• individually converted G-Class projects

Heavy vehicles particularly benefit from strong low-rpm torque.

In these applications, a very high peak horsepower figure is often less important than having sufficient torque available early and across a wide operating range.

This is one of the principal objectives behind the OM606 D35 LA.

OM606 D35 LA for W140 and Other Mercedes Projects

The D35 LA engine is not limited to the G-Class.

It can also provide the basis for other individual Mercedes-Benz projects, including:

• Mercedes-Benz W140

• classic Mercedes conversions

• high-performance road cars

• off-road projects

• special-purpose vehicles

• selected marine applications

• motorsport projects

Every engine configuration is developed according to its intended use.

A road vehicle, an expedition vehicle and a competition engine should not receive identical specifications.

Lubrication and Thermal Management

Increasing engine output also increases the demands placed on the lubrication and cooling systems.

Engine oil performs several critical functions:

• lubrication

• friction reduction

• bearing protection

• heat transfer

• contamination transport

For high-performance applications, oil pressure and oil temperature must therefore be considered as part of the complete engine concept.

The same applies to the cooling system.

More fuel and more engine output ultimately create additional heat that must be controlled.

For this reason, reliable high-performance engine construction requires considerably more than reinforced internal parts.

The thermal balance of the entire engine must remain under control.

Engine Monitoring and Data Logging

For demanding engine projects, monitoring the actual operating conditions of the engine provides valuable information.

Depending on the project, parameters can include:

• engine speed

• engine oil pressure

• engine oil temperature

• coolant temperature

• boost pressure

• intake air temperature

• exhaust gas temperature

• lambda value where appropriate

• additional pressure and temperature values

• data logging

Monitoring these values allows the actual operating condition of the engine to be evaluated.

It can also help identify abnormal operating conditions before they result in major damage.

For special projects, individual display, control and safety functions can also be integrated.

Complete OM606 Engine Building in Our Workshop

The OM606 D35 LA is not based on assembling a collection of aftermarket components.

The engine requires precision machining and careful integration of all relevant systems.

Our capabilities include areas such as:

• complete engine rebuilding

• engine block machining

• cylinder boring

• honing

• cylinder head machining

• valve and valve seat machining

• turning

• milling

• dimensional inspection

• custom component integration

• engine assembly

• mechanical Bosch injection pump rebuilding

• mechanical injection pump calibration

• injector service

• turbocharger matching

• engine monitoring

• data logging

This allows us to combine engine machining, engine building and mechanical diesel injection technology within one complete project.

Engine, Injection Pump and Turbocharger from One Technical Concept

A high-performance OM606 should never be developed as three separate systems consisting of an engine, injection pump and turbocharger.

They influence each other directly.

More fuel changes:

• combustion pressure

• torque

• exhaust temperature

• exhaust energy

The turbocharger influences:

• airflow

• boost response

• intake temperature

• exhaust back pressure

The engine itself determines:

• displacement

• compression

• airflow demand

• mechanical load limits

• thermal limits

For this reason, our objective is to develop the complete system around the intended application.

Not an Off-the-Shelf Engine

An OM606 D35 LA is not built according to one universal specification.

Different customers require very different engine characteristics.

A heavy G-Class used for travelling or towing has completely different requirements from a lightweight performance vehicle.

Possible priorities can include:

• very early torque delivery

• strong pulling power

• excellent drivability

• low operating rpm

• broad torque range

• high peak horsepower

• off-road performance

• towing

• long-distance operation

• marine operation

• competition use

• individual special applications

The engine configuration is selected according to these requirements.

Standard Parts Where They Make Sense

We do not replace every original Mercedes engine component simply because an engine is being modified.

Many original components are very well engineered and can remain suitable depending on the intended application.

Our approach is therefore to determine:

Which component actually needs to be changed?

A component is modified or replaced where technical requirements justify doing so.

This can involve:

• retaining an original component

• machining an existing component

• using a reinforced component

• modifying component geometry

• manufacturing a special component

• developing a completely new solution

This engineering-based approach avoids unnecessary components while concentrating on the areas that actually determine the performance and reliability of the engine.

Custom Components and Special Solutions

Standard replacement or performance parts are not always suitable for special engine projects.

For individual OM606 applications, custom technical solutions may be required.

Depending on the project, this can include:

• component measurement

• geometric adaptation

• mechanical machining

• special pistons

• special connecting rods

• modified rotating assemblies

• individually configured fuel injection systems

• custom turbocharger concepts

• specialized engine monitoring

Exact dimensions, engineering parameters and proprietary details of our own engine developments remain confidential.

OM606 D35 LA – 3.5L Stroker Engine

Internationally, an engine concept of this type is often described as an OM606 3.5L stroker, OM606 3.5 stroker engine or 3.5-litre OM606 engine build.

Our OM606 D35 LA follows a more comprehensive approach than simply increasing crankshaft stroke.

The increased displacement is combined with:

• increased cylinder bore

• modified crankshaft geometry

• special pistons

• special connecting rods

• precision block machining

• cylinder head preparation

• mechanical injection pump calibration

• turbocharger matching

• engine monitoring where required

The entire engine is designed as one technical system.

Frequently Asked Questions About the OM606 D35 LA

Is the OM606 D35 LA an original Mercedes-Benz engine?

No.

Mercedes-Benz did not produce an OM606 D35 LA as a standard production engine.

The OM606 D35 LA is our specially developed approximately 3.5-litre engine concept based on the Mercedes OM606 platform.

Is the OM606 D35 LA the same as an OM606 3.5 stroker?

The term OM606 3.5 stroker is commonly used internationally for increased-stroke OM606 engine builds.

Our D35 LA concept goes beyond a simple crankshaft stroke increase.

It combines increased bore, modified stroke, special pistons, connecting rods, precision engine machining and an individually matched injection and turbocharger system.

What cylinder bore does the OM606 D35 LA use?

Our D35 LA engine concept uses 89 mm pistons, compared with the standard 87 mm cylinder bore of the OM606.

How much power can an OM606 D35 LA produce?

Depending on configuration, applications with up to approximately 750 hp and up to 1,450 Nm of torque can be realised.

The appropriate specification depends on the intended use of the engine.

Maximum output is not the correct target for every vehicle.

Why increase OM606 displacement to 3.5 litres?

Additional displacement can provide important advantages for torque development and turbocharger response.

Particularly in heavy vehicles, increasing displacement can help create strong performance at lower engine speeds.

Can the OM606 D35 LA be used in a Mercedes G-Class?

Yes.

The Mercedes-Benz G-Class is one of the particularly interesting applications for our D35 LA engine concept.

Possible vehicle generations include W460, W461 and W463.

Can you build an OM606 D35 LA with a mechanical injection pump?

Yes.

Mechanical Bosch inline injection pumps are one of our principal specialist areas.

The pump can be built and calibrated according to engine displacement, turbocharger configuration, vehicle and intended performance characteristics.

Can my existing OM606 engine be converted?

A customer-supplied OM606 can potentially be used as the basis for a D35 LA project.

However, the condition of the engine block, cylinder head, crankshaft and other relevant components must first be inspected.

Only after inspection can we determine which components can be reused and which require machining or replacement.

Do you supply complete OM606 D35 LA engines?

Complete engine projects can be discussed individually.

Depending on the project, the scope can range from mechanical machining and component preparation to a complete engine build including injection system and other associated components.

Complete Engine, Customer Engine or Individual Project

Different project scopes are possible depending on customer requirements.

These can include:

• complete OM606 engine rebuilding

• conversion of a customer-supplied OM606

• complete OM606 D35 LA engine build

• precision engine machining

• cylinder block machining

• cylinder head rebuilding

• special engine components

• mechanical Bosch injection pump building

• injection pump calibration

• turbocharger concept

• engine monitoring

• individual special projects

The exact scope is determined according to the engine, vehicle and intended use.

International OM606 Engine Projects

We work with customers and specialist companies beyond Germany.

Complete engines, engine components and injection pumps can be supplied to our workshop for inspection, rebuilding and individual project work.

For international projects, we recommend providing detailed information before shipping components.

Useful information includes:

• engine type

• engine number if available

• vehicle

• country

• intended application

• desired horsepower

• desired torque characteristics

• transmission

• existing injection pump

• existing turbocharger

• current engine condition

• photographs

• requested scope of work

For commercial customers, purchase order numbers, commission numbers and internal project references can also be assigned to the job.

Technical Enquiry – OM606 D35 LA

For an initial technical assessment of an OM606 D35 LA project, please provide as much information as possible.

Useful details include:

• existing engine type

• vehicle or application

• engine condition

• desired horsepower

• desired torque characteristics

• transmission

• vehicle weight

• axle ratio where relevant

• existing fuel injection system

• existing or planned turbocharger

• intended engine speed range

• road, off-road, towing, marine or competition use

• requested scope of work

Photographs of the engine and vehicle installation can also help with the initial assessment.

OM606 D35 LA by Einspritzpumpen Manufaktur NRW

The OM606 D35 LA represents our approach to high-performance Mercedes diesel engine building.

The objective is not to combine the largest possible turbocharger with the maximum possible fuel delivery.

Instead, we develop the engine as a coordinated technical system.

Displacement, crankshaft, pistons, connecting rods, cylinder head, mechanical injection pump, turbocharger, lubrication, cooling and engine monitoring must work together.

By combining engine building, precision machining and mechanical Bosch diesel injection technology, we can develop OM606 engine projects according to the actual vehicle and intended use.

From a torque-focused Mercedes G-Class to an individual high-performance OM606 project, the engine is configured around the application rather than around a single maximum horsepower figure.

OM606 D35 LA – approximately 3.5 litres, mechanical diesel injection and up to 1,450 Nm of torque.