RETIRING THE DECK-PLATE SUPER B
Before we had the mega-horsepower machines we have today, Super Stock competitors were running factory, cast-iron blocks—and they lived on the edge with virtually every pass they made. Shortly after the release of the 6.7L Cummins, an engine that came with thicker cylinder walls than the 5.9L thanks to its siamese cylinder bores (and that was readily available vs. the scarce billet block availability at the time), Van decided to make the 6.7L block the foundation for the Haisley Machine Super B program. For added reinforcement, a bedplate was utilized to tie the main caps in with the lower portion of the block and the block’s water jackets were filled with concrete. The block was also machined to accept ductile iron sleeves and fitted with a 1-inch thick deck-plate to limit cylinder bore distortion.
Now that you know that, you should know this. In every Cummins block, there is a horizontal oil passage in very close proximity to the number 2 main bearing. This oil passage is the weakest link within the OEM block and is where most blocks crack due to high-horsepower and excessive cylinder pressure. When Van’s Super B engines began to creep beyond the 3,000hp mark, block failures were beginning to surface. “If you watched your data logger close, you would see a 10-psi drop in oil pressure,” Van told us.
“And upon teardown the factory horizontal oil passage across the number 2 main bearing was usually found to be cracked.” Though Van and the Haisley team were able to get by with externally tying the block together, the time to switch to a stronger block was fast-approaching.
Machined from a giant chunk of forged-aluminum, Van’s new billet-aluminum block is void of any internal oil or water passages (the block is fed oil externally), which makes the block significantly stronger than the factory Cummins version. The aluminum block is wider as well, with considerably more meat down the side of the block. Last but not least, Van also designed the block to accept two additional head fasteners. Over-engineered? Maybe. But if 3,500-plus horsepower is to be survived night after night for an entire season and then some, over-building is highly welcomed.