Cummins KTA 19 Engine Parts - Connecting Rod Section

Connecting Rod Components for Cummins KTA19 Engines

The connecting rod assembly in a Cummins KTA19 engine is the critical mechanical link between the piston and the crankshaft, transferring combustion force into rotational energy. At Diesel Pro Power, we provide premium-quality connecting rod components and accessories for the KTA19 and QSK19 engine families—trusted worldwide in marine, industrial, and power generation applications.

Overview of Connecting Rod Function and Construction

The connecting rod in the Cummins KTA19 is a forged steel component engineered to withstand immense mechanical stress and heat cycles. It operates in high-load environments, especially in commercial marine engines and heavy-duty industrial engines where reliability is paramount. Each rod consists of a small end (housing the piston pin), a large end (housing the crankshaft journal), and a body that transmits force between the two. Supporting components such as rod bushings, bolts, and bearing shells play essential roles in ensuring smooth engine operation, even at full load and RPM.

Bearing Sets for Cummins KTA19 and QSK19 Engines

Diesel Pro Power offers standard and oversized connecting rod bearing sets for Cummins KTA19 and QSK19 engines, allowing for precise fitment based on crankshaft journal wear and rebuild specifications.

Standard Bearing Set

Bearing Set for Cummins KTA19 and QSK19 – Standard Size
This standard-size set includes the upper and lower bearing shells necessary to service a single connecting rod. These precision-machined shells maintain optimal oil clearance for lubrication and reduce friction during engine operation. Manufactured to OEM specifications, these bearings ensure durability in high-compression environments.

Use Case: Ideal for fresh builds or engines where crank journals measure within original tolerances.

0.010" Oversize Bearing Set

Bearing Set for Cummins KTA19 and QSK19 – Oversize 0.010”
These oversize bearings accommodate a crankshaft journal that has been ground down by 0.010 inches. This size is commonly used in rebuilds where minor wear or scoring required resurfacing of the journal.

Why Choose This Size? If micrometer readings on the crankshaft journal indicate slight wear beyond standard tolerances, this set provides the required oil clearance and fit.

0.020" Oversize Bearing Set

Bearing Set for Cummins KTA19 and QSK19 – Oversize 0.020”
Engine technicians turn to 0.020” bearings when more significant journal wear is present. This set is precision-fitted to journals that have been machined to 0.020 inches under OEM diameter, ensuring the connecting rod maintains proper movement and oil film thickness.

Installation Note: Ensure journals are within manufacturer limits before installation and use assembly lube during rebuild.

Connecting Rod Bushing for Cummins K19, K38, K50, and QSK19 Engines

The small end of the connecting rod features a bushing that houses the piston pin. Over time, this bushing can wear down due to repeated loading and lack of lubrication. Diesel Pro Power supplies high-quality bushings designed to restore factory-clearance tolerances.

Key Features:

• Material: Precision-machined bronze alloy for optimal durability and thermal resistance.
  
  

• Fit: Designed to press into the small end of the connecting rod for a secure, interference fit.
  
  

• Application: One bushing per connecting rod.
  
  

Why Replace the Bushing?
Excessive bushing clearance can cause piston slap, poor compression, or wrist pin failure. Replacing the bushing during overhaul ensures consistent piston travel and reduces knock.

Cummins Connecting Rod Bolts – Secure Load Handling

Each Cummins KTA19 connecting rod requires two high-strength bolts to fasten the rod cap to the rod body. These bolts are torqued to precise specifications to ensure proper clamping force.

Product Details:

• Material: Heat-treated alloy steel
  
  

• Application: Two bolts per rod
  
  

• Importance: Connecting rod bolts maintain the integrity of the big-end cap during extreme engine conditions. Stretch or fatigue in these bolts can lead to catastrophic rod failure.
  
  

Installation Tip: Always use new bolts during rebuilds. Reusing rod bolts can result in incorrect clamping force due to bolt stretch.

Understanding the Complete Role of the Connecting Rod System

Dynamic Forces and Load Transfer

In a 19-liter inline-6 engine like the Cummins KTA19, the combustion chamber generates thousands of pounds of force with every power stroke. The connecting rod:

• Transfers that force to the crankshaft,
  
  

• Maintains precise angular motion,
  
  

• Balances reciprocating mass with other rods and pistons to prevent vibration.
  
  

Because of this role, any wear in the rod bearings, bushing, or bolts can throw off engine balance and jeopardize long-term durability.

How to Inspect and Replace Connecting Rod Components

Inspection Checklist:

1. Visual Cracks: Use dye penetrant inspection to detect cracks in the rod body.
   
   

2. Bearing Wear: Look for scoring, pitting, or discoloration.
   
   

3. Bolt Stretch: Measure bolt length before reuse. Discard if stretched beyond specification.
   
   

4. Bushing Fitment: Ensure piston pin fits snugly into the bushing without excessive play.
   
   

Rebuild Steps:

1. Remove rod cap and inspect bearings.
   
   

2. Measure crankshaft journal with micrometer.
   
   

3. Select correct bearing size (Standard, 0.010", 0.020").
   
   

4. Install new bushings using a press and ream to proper clearance.
   
   

5. Install new bolts and torque to specification.
   
   

6. Check rod side clearance and end-play.
   
   

Interchangeability and Compatibility Notes

KTA19, K38, K50, and QSK19 Compatibility

Many connecting rod components—such as bushings and bolts—are shared across the K-series engine family:

• Bushings and rod bolts are typically identical in K19, K38, K50, and QSK19 engines.
  
  

• Bearings are engine-specific based on crankshaft dimensions but are often cross-compatible between KTA19 and QSK19 when part size matches.
  
  

Note: Always consult your CPL (Control Parts List) for exact engine configuration.

Common Symptoms of Worn Connecting Rod Components

Understanding when to replace connecting rod parts can prevent engine failure:

Marine and Industrial Applications of the Cummins KTA19

Common Uses:

• Commercial marine propulsion
  
  

• Power generation
  
  

• Oilfield and mining equipment
  
  

• Pump and compressor drives
  
  

In each of these, the engine may run for thousands of hours at full load. This makes preventative connecting rod service critical for uptime and reliability.

Expert Tips for Technicians

• Tip 1: Always plastigage new bearings during install to confirm oil clearance.
  
  

• Tip 2: Deburr rod caps before torquing bolts to ensure proper mating.
  
  

• Tip 3: Match connecting rods by weight for balanced reciprocating mass.
  
  

• Tip 4: Keep rod bolts lubricated during torque to avoid false readings.
  
  

Why Buy Cummins KTA19 Connecting Rod Parts from Diesel Pro Power?

With over 40,000 satisfied customers, Diesel Pro Power is a trusted global supplier of OEM-quality and aftermarket Cummins parts. Every connecting rod part we supply is:

• Quality-inspected before shipment,
  
  

• Backed by expert customer support,
  
  

• Packaged securely for international delivery.
  
  

Our warehouse ships fast, and we carry inventory for immediate rebuild needs—no waiting, no uncertainty.

Additional Components You May Need

To complete your rebuild or service, consider adding:

• Piston kits
  
  

• Cylinder heads
  
  

• Main bearing sets
  
  

• Gasket sets
  
  

• Rod cap alignment tools
  
  

• Torque wrenches for rod bolts
  
  

• Connecting rod heaters (for bushing install)