Ford Coyote Engines. Jim Smart

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      The Coyote’s steel crank is a class act with highly polished journals and chamfered oil holes. It is a remarkable piece, considering it is a production part and not a high-end racing part. There’s very little you have to do to this crank whether you’re building a stocker, weekend racer, or all-out full-time racer. Dimensions must be examined and documented along with a mock-up before the final build. Dynamic balancing is a must.

      All Coyote cranks have this eight-hole flange, which is on a par with the 4.6L truck crank. This crank can withstand 400 to 1,500 hp. Some racers have pushed it close to 2,000 hp without failure.

      This is the high-compression 11.0:1 flattop hypereutectic piston for naturally aspirated Coyotes. With this much compression, you are limited in terms of boost and nitrous. You want to be careful about how much boost and nitrous you apply to prevent engine damage.

      “Hypereutectic” piston is just a fancy name for “high-silicon-cast” piston. It takes more abuse than a cast piston and doesn’t have the drawbacks and weight penalty of a forged piston. Hypereutectic pistons run quieter because you can run tighter tolerances without consequence. They tolerate the extremes of street and weekend race duty while offering durability. However, if you intend to supercharge or go nitrous, you’re better off with a forged and coated piston for best results.

      Although the Coyote’s powdered-metal stock rod shares the 4.6L’s rod dimensions, it is not the same rod and cannot be interchanged. Although enthusiasts are spooked by the “powdered metal” nomenclature, in truth “powdered metal” is a high-tech forging process that’s actually stronger than classic I-beam connecting rods used in older pushrod engines.

      Another reason Ford opted for a hypereutectic piston is oil cooling jets that keep the pistons considerably cooler, which improves piston life. This approach also allows for faster warm up because oil is in direct contact with one of the hottest parts of the engine right from the start. Ford engineers have proved that crankshaft journals run roughly 25 degrees F cooler with the oil jets, which enables this engine to operate on 87 octane fuel and survive (though 91 octane is optimum).

      Do You Have Oil Cooling Jets?

      It gets confusing because Ford eliminated oil cooling jets in production for a short time, and then brought them back into production for 2015–2016. Not all Coyote blocks have the oil cooling jet provision. And if you’re going to stuff H-beam rods into your Coyote, keep oil cooling jet clearances in mind. Not all rods and pistons clear. It is unknown why Ford dropped the oil cooling jets in production, aside from perhaps cost. As Ford stepped up the power for 2015, it became apparent that oil cooling jets needed to return, especially with high-boost turbo and supercharged applications.

      Most important to remember is clearance issues. Heavy-duty I-beam and H-beam connecting rods may or may not clear the tight confines of the Coyote block. You must first do a mock-up and rollover to make sure everything clears by at least .060 to .100 inch throughout 360 degrees of crank rotation with all rods and pistons (but without rings) installed. Pay close attention to piston skirt to crank counterweight clearances, which can get very tight and are the reason the Coyote doesn’t accept any more than a 3.649-inch (92.5 mm) stroke.

Room for Improvement?

      So what can you do with a Coyote bottom end to make it even more durable than it already is? Ford’s factory steel-forged induction-hardened eight-bolt crankshaft is a masterpiece of engineering. It is virtually indestructible and can take upwards of 1,500 to 2,000 hp. All the Coyote crank really needs is dynamic balancing when you fit it with aftermarket connecting rods and forged pistons. Chamfering oil holes at the journals improves lubrication, and micropolishing journals improves oil control, but you don’t even need that. Ford produces an outstanding piece right out of the box.

      You have the option of going to the BOSS 302 crank (M-6303-M50B), rods, and forged pistons (M-6100-M50BR as piston/rod assembly) if you’re lacking confidence in the factory steel crank. These items are available off the shelf from Ford Performance Racing Parts. Suffice it to say the Eagle, Manley, or Oliver rod coupled with a Manley, Mahle, or Diamond forged piston will get the job done.