Cummins 6bt Cast Iron 3935936 Diesel Engine Cylinder Block

CYLINDER BLOCK PARTS CUMMINS 6BT DIESEL ENGINE CAST IRON ENGINE CYLINDER BLOCK BEST ENGINE BLOCK PARTS

Using a stock block for any performance build has its share of pitfalls, and depending on what you’re building, an aftermarket block or billet block may be the safer option.

“Every platform has inherent weaknesses according to the environment it operates in,” Strube explains. “Stock castings have been heat-cycled thousands of times. Most often, this strengthens the iron composition. However, overheating, bearing failures, decomposition of the iron due to electrolysis, poor coolant/oil contamination will all definitely, result in a shortened lifespan of that foundation.”

The risk of block damage increases the higher you go in boost pressure and horsepower, says Strube. “On a higher output level, the main journal landings can give it up under extreme torsional distortion and result in compromised integrity. This can lead to complete failure where the block cracks/separates, and subsequently, the rotating assembly fails to remain intact.”

Aftermarket billet blocks have tremendous advantages in these prone areas, according to Strube. He says they have significantly increased material strength, reinforced cylinder structures and the increased oiling capacity enable these platforms to withstand exponentially higher output environments. But they are also exponentially higher-priced, and for many diesel performance enthusiasts, a 3,000 hp engine is not in the budget. To this end, some cast iron aftermarket blocks are beefed up in critical areas to handle high power output.

Under normal circumstances, clearances are not an issue on stock blocks if you’re stroking them and adding billet cranks and main caps. Strube says the manufacturers have gone to great extents to provide well-engineered components in most applications. “The issues are encountered when trying to mix components from various companies. Obviously, company A is not going to assume for the design variations of company B and C if one should exist. These complexities are the job of the builder to overcome.”

The biggest challenges builders have with setting up the blocks for a big horsepower build are more from a financial standpoint than anything. Getting customers to understand that power has a price, and there’s only so far you can push the envelope on stock parts, can be a challenge.

“The average application we build for is rarely above 1200 hp,” Strube remarks. “This doesn’t require much in the way of adding to the foundation to support more power. The biggest challenge is developing a clear strategy that provides the customer with a dependable power assembly, capable of withstanding the desired output and remains within the declared financial means.