The only way this monster would look better is between the fenders on a hot street car with big tires. This particular engine is going into a real '69 NASCAR Talladega stock car owned by Brad Smith. The only way this monster would look better is between the fenders on a hot street car wit Jon Kaase drank the Ford blue Kool-Aid a long time ago. His association with the Blue Oval goes back to his NHRA Super Stock days with a 428 Cobra Jet Mustang in the early '70s and has progressed through a stint as crew chief for the legendary Dyno Don Nicholson in NHRA Pro Stock. Kaase (pronounced kah-zee) is best known now for his engines that have won an astonishing 12 straight IHRA Pro Stock World Championships. He's also put a hammerlock on the Engine Masters competition, winning that event four times. So it's safe to say that Kaase knows his way around big-block Fords. So in a flash of brilliance he decided what the world needed was a new Boss 429 head. While it may appear that Kaase came up with the idea and the heads just fell out of the sky a week later, the reality is that the gestation period took the better part of 18 months. To make these heads nestle into the Kaase scheme, they had to bolt on to a standard 429/460 block. Car Craft was lucky enough to be among the first tier recipients of a set of finished castings. We planned to enlist fellow Ford fan Jim Grubbs, owner of Jim Grubbs Motorsports (JGM) to help us through this buildup, but he volunteered before we had a chance to ask. Except for the funny valve reliefs on the pistons, the short-block could easily be mistaken for a typical wedge buildup. Once we had all the parts, the only real custom work was a little grinding on the block to clear the No. 4 exhaust pushrod. Once the engine came together, the final result underscored the investment with an amazing dyno session at JGM that had industrial complex neighbors stopping by to ask what race motor was up on the dyno. Unlike most dyno sessions that demand tremendous effort to squeeze that last ounce of power from the engine, once JGM's Jeff Latimer set the timing at 34 degrees, the only effort was to set the hot lash. The Holley Dominator Ultra carb delivered a great fuel curve right out of the box, and the massively cammed Boss Nine beast cranked out an astonishing 834 hp at a singing 7,100 rpm. The best part is that Kaase says with a bigger carb and perhaps some stiffer pushrods, we could easily make a bunch more power. The days of easy horsepower have arrived. It may not be cheap, but it most definitely is easy. Look closely and you'll notice that our first-choice 4.500-stroke Scat crank pulled virtually the entire piston skirt out of the bottom of the cylinder sleeve. This obviously was not going to work, and since we already had the pistons, we elected to move down to a 4.300-inch-stroke Scat crank and 0.100-inch-longer rods. Look closely and you'll notice that our first-choice 4.500-stroke Scat crank pulled virtua Displacement Lessons We knew Kaase's heads would be barn burners even before we got the first castings. This meant the massive flow numbers would support a big-inch engine. So right out of the box, we found that Scat builds a 4.50-inch stroke crank that will bolt right into a stock 429/460 block. A quick run through the calculator revealed that we could build a monstrous 545ci motor with bolt-on parts. We packaged this long-arm crank with a set of 6.700-inch Scat rods with a custom Kaase-spec'd Diamond piston but then discovered that the long arm also pulled the piston almost completely out of the bore at bottom dead center. This clearly wouldn't work, so we had to regroup. With help from Scat owner Tom Lieb, we were able to assemble a 0.200-inch-shorter crank at 4.300 with a 0.100-inch-longer connecting rod at 6.800 and balance the assembly to match the previous system. So instead of a thumpin' 545ci Ford, we ended up with an only slightly smaller 521ci beast. Just for the record, we learned later from Kaase that A460 and Eliminator castings from Ford Racing and later-production '79 (D9 casting number) blocks all have 0.250-inch-longer cylinder sleeves that would easily accommodate the longer 4.500-inch stroke. Next time we'll add the longer arm. It makes you wonder what a 454ci wedge motor with a set of Kaase's P-51 heads would make. Those heads are a bit more affordable and flow 400 cfm at 0.700-inch lift. DISPLACEMENT BORE STROKE 429 4.36 3.59 460 4.36 3.85 502 4.39 4.15 521 4.39 4.30 545 4.39 4.50 598 4.60 4.50 One weak point in the 429/460 Ford engines is the ridiculously narrow stock cam bearings. Knowing this engine would be subjected to stiff valvespring pressure, Kaase and JGM sell a custom set of 0.080-inch-wider cam bearings using the front bearing from a 351C. One weak point in the 429/460 Ford engines is the ridiculously narrow stock cam bearings. With all JGM's excellent machine work completed and the bearing clearances set right around 0.0025 inch (with a little more for the thrust main), Jim Grubbs assembled the short-block starting with the Scat 4.300-inch stroke crank. With all JGM's excellent machine work completed and the bearing clearances set right aroun Kaase spec'd the flat-top 4.390-inch Diamond 2618 alloy pistons with the necessarily deep valve reliefs to clear the massive Boss Nine valve diameters. Compression computes out to right at a pump-gas-friendly 10:1. Don't tell anybody, but those 6.800-inch Scat H-beam steel rods are Chevy Rat motor pieces. Kaase spec'd the flat-top 4.390-inch Diamond 2618 alloy pistons with the necessarily deep Another common Lima motor ailment is the spindly stock oil pump mount that usually cracks. Kaase makes his own oil pump (right) with a massive base that resists fracture. This larger mount made custom-fitting the Canton two-bolt main girdle a real pain, but the payoff is added durability. Another common Lima motor ailment is the spindly stock oil pump mount that usually cracks. We also need to acknowledge the guys at ARP fasteners who helped us slog through the several iterations of bolts necessary to assemble this Boss Nine. We also need to acknowledge the guys at ARP fasteners who helped us slog through the sever This -8 AN hose that directs oil from the front of the engine to the rear is a JGM modification to ensure plenty of lube oil reaches the rear two main bearings. JGM performs this mod because the 429/460 engines direct oil through the lifters before reaching the mains. The oil pan is a Canton front-sump piece, and we also used a Canton main stud girdle. This -8 AN hose that directs oil from the front of the engine to the rear is a JGM modific 1 | 2 | 3 | 4 | » | View Full Article By Jeff Smith Enjoyed this Post? 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