Shortblock

If there's any truth to readers' letters, the Chew bias in the hot rodding media is like liberal bias in the mainstream media. No one wants to admit it, but there's sufficient evidence that it exists. That being the case, as big-block Ford protégés in need of a mentor, the best man for the job was Jon Kaase. Although he's best known for winning three Jeg's Engine Masters Challenge competitions and powering the last 12 IHRA Pro Stock champions to victory, Kaase is a self-confessed 460 nut. He started tinkering with the big Ford during the '70s, while

Sealing the bores is a Total Seal ring pack (Vi6-, V16-, 3/is-inch). The top and second ring gaps were set at 0.020- and 0.030-inches, respectively. The Napier second rings allow running less tension while still providing excellent seal.

By reducing the size of the big-block Ford's factory 2.500-inch crank pins to 2.200 inches, the Scat crankshaft is compatible with big-block Chevy connecting rods. These measured out at 6.700 inches. Despite hanging from long rods, the pump-gas— friendly Probe SRS 10.9:1 pistons still retain a reasonable 1.450-inch compression height, thanks to the Ford's generous deck height. Most shelf pistons are offered in both 0.030-and 0.080-over diameters.

Eat your metal shavings out, Chevy boys. Fitting a 4.300-inch crank in a big-block Ford requires no grinding whatsoever. Even 4.500-inch cranks only require slight notching of the block. According to Kaase, earlier blocks from the '70s had slightly wider crankcases than later blocks from the '80s and '90s, like the D9TE casting used in our build. Fortunately, the counterweights of most aftermarket cranks are compatible with either block.

Thanks to a generous 10,320-inch deck height, which is actually taller than most aftermarket tall-deck big-block Chevy blocks, hardly any of the piston skirt hangs below the cylinder sleeves at BDC. Later 429/460 blocks had slightly longer sleeves than earlier units.

With the success and popularity of Ford Racing's Super Cobra Jet heads, most piston manufacturers stock off-the-shelf pistons compatible with their revised valve location. Naturally, the same applies to the Kaase P-51s. To tighten up the quench and bump compression, the pistons protrude 0.005 above the block deck, or "five out of the hole."

For all it does right, a notoriously weak link of the 429/460 design is its oil system. To help improve flow, the SAM radiused the passage inside the block between the oil filter mount location and pump flange.

working on Don Nicholson's NHRA Pro Stock team, and has been picking up where the factory left off ever since. His guidance was essential in sorting out the specs on our combination.

The simple goal of this buildup was to produce enough power to push a typical street car deep into the 9s, while still maintaining enough streetability to make an occasional trip down to the Piggly Wiggly. The first order of business was sorting out the ideal bore and stroke dimensions. At 4.360 inches from the factory, a standard-bore 429/460 block offers plenty of deep-breathing potential as-is. "If you're trying to build a l,000hp race motor, then your best bet is a 4.600-inch bore with an aftermarket block. However, there's really no need to bore a block more than 0.030 over on a street motor, although most production blocks have enough wall thickness to safely handle an 0.080-over bore," Kaase explains. Upon scoring a local block off of eBay that had already been rebuilt once, we decided to punch it out to 0.080-over after sonic checking revealed plenty of meat remaining between the bores.

To keep costs at a minimum, we opted for a Scat 4.300-inch cast-steel crankshaft, which is also offered in 4.150- and 4.500-inch configurations. Combined with a 4.440-inch bore diameter, it netted a total of 532 ci. We're not ones to challenge the notion of irreplaceable displacement, but there's certainly a point of diminishing returns. "For a street/strip build like this, I prefer a 4.300-inch stroke," Kaase opines. "As you go

"The cam is so high up in a 429/460 block that you can actually fit a 6.000-inch-stroke crank, and the rods won't hit the cam. With a small-block Chevy or Windsor, you'll run into clearance issues with a 4.000-inch stroke."—Jon Kaase

The Scat rotating assembly is set up for external balancing, but being the race engine builders that they are, the SAM opted for internal balancing, which required adding two slugs of heavy metal and a neutral-balanced 429-style flexplate. Judson says that internal balancing offers a slight advantage in longevity at high rpm, but concedes the benefit is very minor in a 7,000 rpm street/strip motor such as our 532.

The SAM utilizes the latest in diamond honing technology on its state-of-the-art Sunnen SV10. Compared to silicon carbide stones, the diamond honing process dramatically reduces the potential for burnishing the metal. Typical street/ strip motors are often honed to a roughness average value of 20, while our 532 was honed to a super slick value of 9. While it's a subject of debate among engine builders, Judson says that a properly executed race hone provides sufficient oil control to last up to 50,000 miles on the street.

The most effective fix in addressing the big-block Ford's weak oil system is a rugged pump. Even at moderate power levels, a stock-style pump is prone to cracking and breaking at the arm due to engine vibration, something that's only compounded by violent wheel-stands. This monstrous Kaase pump is made from rugged cast iron, and features dual oil feeds to the rotor for increased pressure at all rpm. Each pump is CNC machined inside and out, and tested prior to shipping.

As with the headers, there are a number of fferent oil pans on the market designed specifically for swapping a 460 into a Fox-body Mustang. This 7-quart Moroso pan (p/n 20620) is one of the best out there, and fits beautifully without any beating or banging. The clear zinc coating looks trick, and it has enough clearance for up to a 4.500-inch-stroke crank. According to Kaase, a quality aftermarket pan is a must in any performance 460 build.

bigger in cubic inches with a 4.500-inch crank, you might pick up more torque through the midrange, but the difference in high-rpm power will be negligible." With the bore and stroke dimensions finalized, the rotating assembly was finished off with a set of Scat 6.700-inch steel rods, and Probe 10.9:1 pistons. Scat's kit also includes rings, bearings, a flexplate, and a balancer all under one convenient part number (1-94955BE) for $1,495.

0 0

Post a comment