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Big Ford Horsepower (Part One): Trick Flow Specialties Assembles 598 Cubic Inches of Short Block

Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block
Ford 598 Big Block

Capable of handling over 600 cubic inches (604 to be exact), the Ford Racing A460 block features siamesed bores to increase block rigidity, a plus with large overbores. Other features include four-bolt nodular iron main caps and three inch diameter main journals. Trick Flow had the block bored to 4.600 inches, the cylinders honed with a deck plate installed, the cam tunnel machined for the roller cam bearings, and head mating surfaces zero-decked to 10.300 inches for used with MLS head gaskets. R&R Machine gets the credit for the machine work.

It’s a little hard to see, but a .001 inch of material was removed from the inner corner of the block to gain a little extra clearance for the crank counterweight.

If—saints forbid—the valvetrain self-destructs, screens epoxied over the oil return holes in the lifter valley will help keep the big chunks out of the bottom of the engine.

Roller cam bearings, like these from Ford Racing, can handle high valve spring pressures better than plain bearings, and they help reduce power-robbing friction. These ultra-low-friction needle roller bearings require so little lubrication that you can actually block off the stock cam oiling holes. This reduces both oil aeration and power loss due to windage in crankcase.

The roller cam bearings get oil by old-fashioned splash lubrication from the crank. The cam bearing oil passages in the main journal saddles are fitted with restrictors to help keep more oil around the main bearings.

Main bearing clearance is checked with a dial bore gauge. The caps are torqued to 110 ft.-lbs. with the bearings installed. Recommended clearance for these Clevite H-Series bearings is .0030 to .0031 inch.

The Scat forged crank was balanced at Trick Flow’s facility. The copper-colored weights represent the weight of the piston/ring/connecting rod assemblies. The crank was pretty close to optimal out of the box, requiring just a 65 gram slug of Mallory metal in the front counterweight.

Rod bearing clearance is checked with a dial bore gauge; clearance with the Clevite coated bearings should be .0025 to .0027 inch. Rod bolt stretch was also checked and found to be within the .005 to .006 inch tolerance range.

Piston meets connecting rod. Wiseco designed a custom forged piston just for this build; it has a 6.8cc dome that matches up to the combustion chamber shape on Trick Flow’s PowerPort A460 cylinder heads. Wiseco also applied its ArmorGlide™ skirt coating to reduce friction. The 598 stroker combo uses 6.800 inch big block Chevy rods. Trick Flow sourced a set of Callies Compstar forged H-beams. Note the double spiral locks.

With clearances checked, bearings lubricated, and piston/rod sets assembled, it’s time for assembly. First up is the Scat crankshaft. Forged from 4340 steel, the internally balanced crank has lightening holes in all rod throws; large-radius journals improved strength and wear resistance. The ARP main studs are torqued to 110 ft.-lbs. and the splayed cap bolts to 100 ft.-lbs. (with ARP Ultra-Torque assembly lube).

Todd checks crank thrust (endplay) with a dial indicator. Acceptable endplay for a 460 is .004 to .008 inch; ours came in at .006 inch.

The piston/rod assemblies are slid into their bores. Rod bolts are torqued to 88 ft.-lbs. using CMD #3 assembly lube. Rod side clearance is checked with a feeler gauge; proper clearance is .027 inch.

The COMP Cams mechanical roller cam is a very big stick—duration is 285/300 degrees at .050 inch, and lift is .873/.831 inches (with a 1.8 ratio rocker arm). Lobe separation is 114 degrees.

Unlike timing chains and gear drives, a Jesel belt drive does not transfer the crankshaft (torsional) harmonics to the cam—harmonics that can cause cam timing to jump around. The Jesel belt drive is a “dry” system that requires no oil lubrication. It also allows up to eight degrees of cam adjustability (either advance or retard). The cam sprocket hub had to be machined .0004 inch to bring camshaft end play into proper specifications.

Camshaft endplay is checked and found to be within spec at .004 inch (the range is .002 to .006 inch). The Jesel drive has a removable cam cover that gives you access to the cam without having to disturb the front crank seal. The cam cover has a flexible seal that fits around the cam sprocket to keep the oil in.

The camshaft was degreed to the 110 degree intake center line recommended by COMP Cams (four degrees advanced). Our 598 short block is now ready for the top end, oiling system, induction, and ignition system.

Trick Flow Specialties built a 565 cubic-inch Chevy that was awarded to the IHRA Summit Racing SuperSeries Top Class Champion back in 2012. The big block made 1,013 horsepower. That’s a very respectable benchmark, one that Trick Flow wanted to beat with its next engine.

The solution is cubic inches—lots of cubic inches. That’s something easy to do with a Ford 460-based engine. With a 10.320 inch tall deck, generous 4.900-inch bore spacing, thick cylinder walls, and a huge crankcase that can handle lots of stroke, it’s like Ford engineers designed the 460 just for building big-inch engines.

You can go upwards of 800-plus cubic inches with a 460-based engine, but that means aluminum blocks, stupid-stroke cranks (upwards of six inches), and other expensive custom parts. Trick Flow opted to leave those to the tractor-pull and monster truck guys and went with an engine virtually anyone can duplicate with parts from suppliers like Summit Racing.

The cubic inch limit is about 557 with an OE-style 460 block. Ford Racing’s popular siamesed-bore A460 iron block can handle about 598 cubic inches (4.600 inch bore, 4.500 inch stroke) without a fuss, providing a good balance of size, power (especially torque), and parts availability. Thus, 598 is the direction Trick Flow went.

The Parts

Here are the building blocks for the 598:

Ford Racing A460: Made for racing, this block has siamesed bores to increase block rigidity, a plus with large overbores. Other features include four-bolt nodular iron main caps and three inch diameter main journals.

SCAT Standard Weight Crankshaft: Forged from 4340 steel, this crank gets it all—heat-treat, shot-peening, nitride-hardening, and micro-polishing. The internally balanced crank has lightening holes in all rod throws, and large-radius journals for improved strength and wear resistance.

Wiseco Pistons and Rings: Custom-made part for the short block, the forged pistons have a 6.8cc dome that matches up to the combustion chamber shape on Trick Flow’s PowerPort A460 cylinder heads. The rings are low-friction .043 inch top, .043 inch second, and 3mm oil control.

Callies Compstar Connecting Rods: These big block Chevy-sized H-beam rods are forged from 4340 steel. The rods are stress-relieved and have burnished threads and bolt spot faces so part dimensions stay consistent, no matter how many times they are torn down and reassembled.

Ford Racing Roller Cam Bearings: These ultra-low-friction needle roller bearings require so little lubrication that you can actually block off the stock cam oiling holes. This reduces both oil aeration and horsepower loss due to windage.

COMP Cams Roller Camshaft: Custom-ground for this engine, this is a big cam—285/300 degrees advertised duration at .050 inch and .873/.831 inches of lift (with 1.8 ratio rockers). Lobe separation is 114 degrees.

Jesel Belt Drive: The two-piece camshaft belt drive reduces the amount of harmonics being transferred to the camshaft. That means rock-solid cam timing compared to a timing chain or gear drive. It also has an external cam timing adjustment feature that allows you to accurately set cam timing.

Assembly

Other than some minor machine work (which we’ll cover in the photo captions), the 598 short block was a straightforward build anyone with a decent home shop can handle. We’ve said it before, but it bears repeating: Building a reliable race engine is all about taking your time, keeping things clean and well lubricated, and most importantly, measuring everything at least twice.

Next Time

In the next post, we’ll be finish up the long block—cylinder heads, valvetrain, oiling system, induction, and ignition. We think you’ll like what you see!

Parts List

Ford Racing A460 Iron Block

Scat Forged Crankshaft

Wiseco Forged Pistons, set of 8 (special order from Summit Racing)

Wiseco Piston Ring Set

Callies Compstar H-Beam Connecting Rods, set of 8

ARP Main Stud Kit

Clevite H-Series Main Bearing Set

Clevite H-Series Rod Bearing, each (8 required)

Ford Racing Roller Cam Bearing Set

COMP Cams Roller Camshaft (special order from Summit Racing)

Jesel Belt Drive System

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7 Comments

  1. Pingback: Big Ford Horsepower (Part 3): Dyno Results for Trick Flow Specialties' 598 Ford - OnAllCylinders

  2. Pingback: Big Ford Horsepower (Part 2): Installing the Top End on Trick Flow Specialties' 598 Ford - OnAllCylinders

  3. Nice good job

  4. James kramet says:

    You know you’re close to patent infringement

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