While some see it as a challenge to push the performance limits of factory hardware, there is one certainty. Eventually, those stock parts will fail as power increases well beyond the intended engineering of said parts. That is especially true when it comes to stock engine blocks, which is why World Products completely reimagined the small-block Ford from the ground up to create its Man O’War blocks.
“As you well know, one of the great things about the factory small-blocks is that they are lightweight castings,” Jack McInnis, Marketing Director at World Products, said. “One of the bad things is that they are thin-wall castings. They are good for about 400 to 450 horsepower and then things get sketchy, with blocks having a reputation for splitting into a pair of four-cylinder units.”
In its newest iteration, World’s Man O’War block steps the material up to a 40,000-psi alloy and adds even more material to the main webs. — Jack McInnis, World Products
While there are a few blocks to chose from these days, World Products offers its Man O’War blocks in 8.2-inch and 9.5-inch deck height as direct replacements for 302- and 351-cube Ford small-blocks. To ensure these blocks are battle ready, the company worked with a NASCAR team and used CAD/CAM and 3D design to create race-worthy blocks from the ground up.
These block include several new enhancements, like thicker mains, and perhaps most importantly, they are built from a more durable, high-density iron alloy meant to better survive the elevated horsepower levels created by today’s builders and power adders.
“Aftermarket blocks typically upgrade the material from the factory gray iron to a 30,000-psi grade and add material in specific areas to increase strength. In its newest iteration, World’s Man O’War block steps the material up to a 40,000-psi alloy and adds even more material to the main webs over and above the previous thickness,” Jack explained.
These areas are crucial to prevent the blocks from splitting in two as horsepower levels climb. When boost or nitrous are multiplying the engine’s power output, the thicker sections are built to hold up, where some lesser blocks might give way. World was careful to add beef where it was needed, however, as they actually went with smaller fasteners to seal the heads.
Man O’ War Cylinder Head Specs
Casting ID Number: WOR-081
Material: 355-T6 alloy high density aluminum
Valve Seats: Intake (hardened), exhaust (hardened)
Valves: 2.25-inch Intake, 1.625-inch Exhaust
Valve Guides: Manganese bronze
Spring Seats: Machined for 1.560-inch
Valves: Manley stainless steel valves in assemblies
Guide Plates: Proprietary World (PN 830463-8)
Rocker Arms: Shaft mount system required
Intake Runner: 275cc or 285cc, standard port location
Exhaust Ports: 102cc, standard location
(dual exhaust bolt pattern to accommodate large custom headers)
Combustion Chamber: 64cc
Spark Plug: 14mm, .750-inch reach gasket style
Valve Job: Multi-angle intake and radiused exhaust
Valve Cover Rail: Raised
Valve Angle: Stock 10 degrees
Accessory Bolt Holes: Stock
Those smaller fasteners allow for more meat around the Siamesed cylinder bores. The blocks feature a .600-inch deck so it is tough enough for high-compression, naturally aspirated combinations or combinations with forced induction. They can be had with a 3.995-inch bore (measures 4.000-inch when finished) and a 4.120-inch bore (4.125-inch when finished).
Speaking of the fasteners, these blocks support using more than the traditional four bolts per cylinder. The Man O’War blocks feature six studs per cylinder and the holes are not tapped into the more expansive water jackets. Though only some cylinder heads — like World’s own Man O’War Windsor heads — can use additional fasteners, having that extra clamping force can really help maintain cylinder head seal at eye-watering boost levels.
“Another important feature is that the cylinder barrels are extended half an inch at the bottom for better piston support in stroker applications, and the blocks come already clearanced for stroker cranks,” Jack added.
Man O’War Block Features
• 40,000-psi iron alloy
• Increased main web thickness
• 7/16-inch ARP main fasteners
• Exclusive six head bolts per cylinder
• Cylinder barrels extended 1/2-inch
• Clearance for 3.500-inch stroke at 8.200-inch
• Clearance for 4.250-inch stroke at 9.500-inch
• Nodular or billet four-bolt main caps
• Dowelled and stepped register caps
• Low-restriction priority main oiling
• Increased oil drainback from heads
• Provision for dry sump oiling
• Accepts standard small-block Ford components
“The Man O’War blocks with nodular iron main caps use ARP bolts and the billet cap blocks use ARP studs to secure the caps. Both have dual registration, both stepped and dowelled,” Jack said. “We also improved the priority main oiling system to further reduce restriction and increase oil flow.”
To further reduce bearing speeds and improve durability, the 9.5-deck blocks utilize the popular Cleveland main dimension of 2.749-inch, while the 8.2-deck blocks stick with the traditional, 2.248-inch main dimension.
Despite being far more rugged, these blocks are quite traditional when it comes to accepting factory-style equipment, like starters, fuel pumps and oil pans, though they can be run with wet or dry-sump oiling.
In short, if you have a big-power small-block project in mind, the Man O’War deserves serious consideration as your foundation, whether you are building a high-winding nitrous 302 or a big-cube, boosted Windsor combo — or any other permutation, these blocks are built to survive.
You can learn more about the Man O’War small-blocks by visiting the company’ official site here.