Why Buy Cummins K Series Parts

Breaking down the difference

cummins part shown over poor performing oem part

We tested 237 non-genuine components for 19L and above engines including pistons, rings, valves, cylinder liners, connecting rods and pins. In virtually every case, issues were identified which would have a negative impact on fuel economy, performance, blow-by, reliability and durability.

Below is a summary of findings for each part, and the danger of using anything but genuine Cummins parts.

View K Series brochure

POTENTIAL IMPACTS

Pistons

Issue	Damage/Performance
Shallow ring grooves	Ring breakage, high oil consumption, blowby, scuffing
Out-of-spec bowl dimensions	Excess heat, cracking, high fuel consumption, visible smoke
Debonding of ring carriers	Catastrophic engine failure

Piston rings

Issue	Damage/Performance
Out-of-spec ring angles	Insufficient sealing, excess fuel usage, decreased performance
Incorrect size of oil ring (too thick)	Poor oil scraping, excessive oil consumption
Incorrect size of top ring (too thin)	Excess rotation, poor sealing, increased blowby

Piston pins

Issue	Damage/Performance
Missing from some kits	Repaid delays, downtime, extra cost
Out-of-spec outer diameters	Incorrect fit issue, repair delays
Intergranular oxidation	Manufacturing defect, increased potential for premature fatigue and cracking

Cylinder liners

Issue	Damage/Performance
Oversize outer diameters	Radial stress leading to metal fatigue
Insufficient lower outer diameters	Liner rocking and fretting
Oversize inner diameters	Cavitation leading to pitting, coolant leaks and mission-disabling failure
Improper cross-hatching	Compromised lubrication, increased wear, higher blowby and oil consumption, decreased service life
Excess crystals in liner coating	Poor coating adhesion
Insufficient metal strength	Premature wear, potential failure

Valve springs

Issue	Damage/Performance
Below spec for hardness	Degraded performance over time
Insufficient height load	Improper seating resulting in combustion leaks and premature wear-out of valve seat inserts

Valve seat inserts

Issue	Damage/Performance
Runout does not meet specifications, can't square to seat	Increased wear, combustion leakage, potential valve failure

Connecting rod bearings

Issue	Damage/Performance
Tangs too narrow	Interference issues, misalignment of oil holes hindering oil flow
Metals sintered, not cast	Lower corrosion resistances
Excess lead pooling	Fatigue cracking

Connecting rod bushings

Issue	Damage/Performance
Excess lead in lining layer	Delamination and crackin

Saving a little upfront could ultimately cost you

Using non-genuine parts does more than compromise the performance of your high-horsepower engine.

It jeopardizes your business and makes it hard to meet customer expectations. The miniscule amount you save upfront using non‑genuine parts is likely to cost you big time down the road. When your profitability and reputation count on it, use Genuine Cummins Parts to assure continuous performance.