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Hot Rod Guide To The StarsCadillac Hot Rod Fabricators on the Cadillac Northstar. From the February, 2009 issue of Popular Hot Rodding By Chris Shelton
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Cadillac Hot Rod Fabricators (CHRF) has the goods to adapt Cadillac's otherwise transversally mounted Northstar engine to just about any longitudinally mounted application. They also have some pretty trick essential and problem-solving parts like engine mounts, hot-rod friendly intake shrouds and cam covers, oil filter relocation adapters, and even overdrive transmissions modified specifically for the application. We visited CHRF for the nitty-gritty go-fast speed stuff, and learned how, depending on tune, the Northstar will churn a healthy 295hp in stock form. However, bolt CHRF's cams in place, ditch the stock exhaust for a tuned tubular system, and the Northstar starts whipping up 375 to 380 horses. For stage two, shop owner Alan Johnson suggests mild headwork and 11:1 forged pistons to bump that number up to 410-415hp. For the third stage, Johnson runs low-deck forged slugs, forged I-beam rods, stock-ported heads, and pressurizes the intake by 5 pounds with a 177ci Roots-type Weiand blower. He says that combo with stiff springs and the cams works out to about 525hp. Now get this: bolt a 256 Roots-type Weiand blower on in lieu of the 177, top it with twin throttle bodies, and net about 650hp. Mind you, this is on race gas; less boost and street fuel will net about 600 horses. Johnson also mentioned that several of his applications make in the 800hp range with twin turbochargers spinning up to 20-pounds boost. Of course, boost levels like that require octane levels far higher than what's available at the corner store, so they might not jibe well in the weekend cruiser. We'll keep the introduction short, as real estate comes at a premium and we've got lots to show off. We even scrounged up some Cadillac OHV history to further solidify the parallels between these two engines. There's enough here to get any die-hard speed freak's mouth watering. Now get to it!  Even though the stock manifold...  Even though the stock manifold supports pretty heavy power figures, Alan Johnson said he knew he needed a versatile manifold for the next step, so he tooled up for a cast-aluminum, single-plane piece in 1998. It does the things that the stock manifold can't quite do: make huge power. Even with the single-plane arrangement with a large plenum, Johnson cites the efficient port/valve arrangement and subsequent high port velocity as the major contributor to low- and mid-range driveability--even on a stock engine.  Johnson fabricated the manifold...  Johnson fabricated the manifold with a universal square-bore mounting flange for the utmost versatility. That works out great for the true techno-phobic; any standard square-bore carburetor bolts straight up for nearly out-of-the-box performance. The tradeoff for carburetor simplicity: loss of port-injection part-throttle response, fuel economy, and low-end torque.  The manifold can permit best-of-both-worlds...  The manifold can permit best-of-both-worlds performance...  ...For starters, Johnson uses...  ...For starters, Johnson uses Holley's Commander-style programmable fuel injection systems with the manifold for throttle-body performance...  ...He said he prefers the...  ...He said he prefers the Holley systems for their simple tuning. He matches the ECU with one of his simple, foolproof harnesses. Incidentally, CHRF recalibrates the ECU to work specifically with the Northstar.  For port-injected applications,...  For port-injected applications, Johnson runs the Commander system with eight independent injectors and a throttle body--in this case a 1,000-cfm four-holer.  For the truly adventurous,...  For the truly adventurous, Johnson machines the manifold to accommodate several superchargers, including the Weiand 177 and 256 models, as well as the Whipple twin screw-type 3800 blower.  Here's one of the Weiand Roots-style...  Here's one of the Weiand Roots-style blowers with twin throttle bodies. This is the combination Johnson runs for the 650-horse applications. As usual, he controls all spark and fuel functions with the Holley Commander.  Johnson also CNC machines...  Johnson also CNC machines these crown rings to support the cylinder's top end. In theory, the wet-jacket cylinders could walk about under the head under extreme boost pressures. While Johnson says the verdict is still out on whether or not they're necessary (neither he nor scads of Honda drag racers who also run wet jackets have had problems), he still offers them for the truly cautious.  Before we dip into the engine,...  Before we dip into the engine, we thought we'd show one of Johnson's hand-fabricated Pro Stock-style manifolds. This one uses two Ford 4.6 modular throttle bodies and Bosch-style fuel injectors. It illustrates the Holley Commander's universal appeal.  Manufacturers love hypereutectic...  Manufacturers love hypereutectic pistons because they don't expand. That means tighter bore clearances, better cold ring seal, and a quieter engine. However, brittle hypereutectic pistons end up in the pan when subject to heavy pressure. So after cams and headers, Johnson advises a set of forged aluminum pistons. Arias worked with Johnson specifically for these. They feature tool-steel pins with stock diameters for most applications and larger diameters for heavy boost settings.  While stock-powdered metal...  While stock-powdered metal rods work in boost applications, they don't work so well with boost figures over 10 pounds. For those applications, Johnson stocks forged Eagle I-beam rods with ARP rod bolts. For even wilder boost applications, Johnson carries from Billet Crower I-beam rods with even bigger ARP bolts.  Cadillac Hot Rod Fabricators...  Cadillac Hot Rod Fabricators stocks five cam types for naturally aspirated applications: 272-, 280-, 288-, 300-, and 310-degree duration (measured at .050-inch) sticks. Between the possible cam combinations (remember, two sets) and camshaft indexing (CHRF offers offset-drilled cam gears), just about any power curve is possible.  Overhead-cam design eliminates...  Overhead-cam design eliminates a few things: pushrods, rockers, adjusters, and their attendant weight. As a result, OHC designs use lower spring pressures--in this case 96 pounds at .400-inch stock--which frees up yet more power. However, ultra-low pressure won't tolerate long duration cams and their higher engine speed levels. For cam swaps, CHRF offers springs in 180-pound rates at .400-inch lift.  Cadillac designed efficient...  Cadillac designed efficient ports with high flow rates and velocity. There's room for improvement, though. Johnson offers several porting packages dependent on the state of tune. The left photo shows a modified intake port, the photo at right shows a modified exhaust. Up to 50-cfm increases are common.  Now that we've got you good...  Now that we've got you good and primed, we thought we'd show two very important identifying characteristics on the Northstar. First, look for a round boss cast on the pan rail; it denotes engine size (why didn't manufacturers do this sooner?). The big cheese: the 4.6. While the Oldsmobile Aurora is basically the same motor, it comes in at 4L and features smaller cylinder head components. The boss indicates it.  Secondly, the date code badge...  Secondly, the date code badge cast in the head tells a story all its own. According to Johnson, early engines ('93-94) are good baseline engines, whereas Cadillac designers introduced a new manifold for '95 engines. For engines made in 1996, they introduced a new throttle body. Now here's the real catch: find a '97-99 engine. They've got hard-chromed valve stems. Cadillac redesigned the Northstar for 2000. While it's similar to the earlier units, no earlier parts fit it, it has huge intake valves and runners (a boon), but smaller exhaust valves and runners (a bust). The result, according to Johnson, is a poor intake/exhaust ratio. The Overhead Cadillac:
The Stuff of Legends
The Northstar isn't exactly Cadillac's first venture into high tech. Along with two V-16s, a V-12, and early ventures into hydraulic lifters and a pre-war automatic transmission, Cadillac made a name for itself with cylinder head technology. There's a name that goes along with that history, and it has quite a bit to do with our hobby. Way back in 1930, the year Cadillac introduced its first V-16, GM appointed a young Ed Cole as ward of Cadillac. By 1933 he graduated head of his class and started as a lab assistant in Cadillac's engineering department. He ascended the ranks and eventually oversaw Cadillac's wartime involvement--a position that netted him chief engineer status following the war. His post-war pet project: a short-stroke, high-compression, overhead-valve engine--a first of its kind. Cadillac introduced it in the 1949 model year. The following year Cadillac proved overhead-valve skeptics wrong by placing 3rd, 10th, and 11th in the 24 Hours of LeMans. Needless to say, the engine's power to weight ratio and technological advancements caught on big with the hot rod crowd. The burgeoning aftermarket picked up on the trend, and by the early-'50s, companies like Evans, Edelbrock, Sharp, and Iskenderian tooled up for speed parts. By the close of the '50s, Cadillac increased its V-8's displacement by 59 ci and doubled its power output. So when Cole transferred to Chevrolet in 1952, nobody doubted his objective: design a lightweight, low-cost V-8 for the Chevrolet lineup. Its code name: the Chevrolet small-block. While no parts interchange between the Cadillac and Chevy, many parts look eerily familiar. More than one parts scrounger bought a Caddy timing cover while looking for Chevy parts. Ed Cole's legacy at Cadillac still shines through in their achievements. The Northstar is merely the latest chapter. So whenever anybody chides the overhead-cam Northstar for being too "high tech," remind 'em of Ed Cole and his "high-tech" overhead-valve Cadillac V-8.
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