Power Company II

Power Company II

Kevin Stoa Engine Build part 2 of 3. Text & photos by Sam Logan:   Probably the biggest fallacy about engine power output is the number that reveals its peak power. But it’s a deceit perpetuated by most of us. We run our finger down the page looking for it. The engine builder pursues it because often his job rests upon it, the car owner requires it, and the crew chief desires it—even magazine titles splash it across their covers, using it to entice greater magazine sales. The result is that the racer shopping for an engine almost always inquires of its peak power and the circle is complete: everyone engages in racing dynos.  “In the eighties,” says Keith Wilson of Wilson Manifolds, “when I ported Childress race engines, their star Dale Earnhardt Sr. never cared about peak power. Instead he spoke of feeling it in the seat and dynamometer figures were of little account, he wanted to feel the car accelerate coming off the corner.” Kevin Stoa, the accomplished IMCA Modified racer and engine builder says, “The key in making the car accelerate is to determine its most effective RPM range. If the best oval track engine builder in the world made unrivalled peak horsepower from 8,500 to 9,500rpm, his engine would be beaten every time by another that’s producing its full power from 6,500 to 7,800rpm because it accelerates faster.” Bigger induction runners, for example, will often demonstrate impressive power on the dyno, but under racing conditions they often disappoint with lackluster throttle response. “Dirt track racers make most of their overtaking maneuvers when coming off the...
Power Company III

Power Company III

Kevin Stoa Engine Build part 3 of 3. Text & photos by Sam Logan: Let’s say your 400cu in race motor operates under water, like a fluid pump, and with every two revolutions of the crankshaft it would ingest and displace 400 cubic inches of water—receiving it through its intake and discharging it through its exhaust. But when the engine operates with air, especially at high engine speeds and equipped with a small cross-sectional area in the intake ports, it will consume more than its stated displacement. By pulses and resonant tuning and inertia and air speed and all kinds of trickery, the savvy race engine builder knows the more air he can persuade to enter his cylinder the more power he will generate. Carefully, using the cylinder bore as his beginning point, he’ll usually select the largest intake valve he can fit into the combustion chamber, making sure its head is positioned at an appropriate distance from the cylinder wall. Positioning it too close to the wall creates a shrouding effect and impedes the flow of the incoming air. He’ll probably use a valve with a concave head to save weight and he’ll surely consider the optimum compression ratio. The more astute will deliberate on exploiting the advantages of squish or “quench” which accelerates the combustion process. On the compression stroke the air-fuel mixture is squished out from the flat, narrow spaces between the piston and the cylinder head and forms fast-moving jets that agitate the mixture and boost combustion speeds. Intake port volume usually isn’t regarded with as much importance as the smallest cross-sectional area, which accelerates...
Kaase’s Top Five: Jon Kaase talks engines

Kaase’s Top Five: Jon Kaase talks engines

By Archie Bosman. Photos by Moore Good Ink: Jon Kaase’s standing was propelled to the forefront of his craft by winning the annual Engine Masters Challenge four times: 2003, ’04, ’08, and 09. But his reputation as an innovative engine builder had already been established over previous decades. Starting his career with the acclaimed Dyno Don Nicholson in 1977, Kaase was instrumental in winning the NHRA Pro Stock championship of that year. In later years he built engines for over a dozen IHRA Pro Stock championship winners. Today Kaase and his team continue to devote their time to building race engines and hot rod engines for all classes, including those with power-adders. In the following paragraphs Jon Kaase provides some insight into his top five power-plants. From his high performance small-block P-38 Windsor engines to Mountain Motor Pro Stock racing units here are some of his comments:   P-38 “The smallest one is the P-38,” says Jon. “These are cylinder heads that suit the 302 and 351 small-block Windsor engines. Initially, they attracted interest slowly, probably because our introduction was a protracted affair. But after six or nine months, sales began taking off, including many welcome orders from our Australian followers. “Now the P-38 has caught the eye of high performance car makers. In fact, we’re about to release a new shaft-style rocker layout and a revised valve cover.” The principal power gains from Kaase’s P-38, you may recall, were derived from its canted, larger diameter inlet and exhaust valves and improved port velocities. Deeper valve bowls with sweeping short turns in the intake and exhaust tracts were further...
The Boss Nine Kaase’s New Boss Nine hemi for street rods and street machines

The Boss Nine Kaase’s New Boss Nine hemi for street rods and street machines

By Ro McGonegal. Pictures by Moore Good Ink: Long-time Mountain Motor engine master Jon Kaase (Racing Engines, Winder, Georgia) says, “The stock Boss 429 parts were a masterpiece for their time, but slightly weak and difficult to work on. We made every effort [with the Boss Nine] to fix anything that was troublesome or failure prone.” At the end of 2007, Kaase decided to take “the plunge and build all new Boss 429 Ford retrofit heads and related parts. I was betting on the fact that there were other Boss fans and Ford enthusiasts out there that wanted these new parts as badly as I did. Although they’ve only been out for a short while, I’m happy to say that they have been well received and successful in whatever projects they have been used in.” Since build orders for the Boss 429 Mustang NASCAR homologation-specials ceased at 1,358 (859 were built in the spring of ’69; 499 more came to life as 1970 models later that summer), these units are rather scarce. Solving the cylinder block problem was easy. Kaase simply undertook the 429/460 big-block (in iron and aluminum) providing them with cylinder head oil drains in the correct location. The JKRE plan included using OE 460 head gaskets, so the deck surface of the Boss Nine heads is much thicker than the original dimension to provide the necessary clamping force. The Boss 429 was humorously under-rated at 375 horsepower while it probably made closer to 475 at the flywheel and without the parasitic drag of the accessories. The ports were huge, had poor low-speed velocity and didn’t begin to...
Canted valve Windsor Head: Ahead of of its time?

Canted valve Windsor Head: Ahead of of its time?

Jon Kaase’s P38 Canted-valve Windsor Cylinder Heads Aim For Better Cylinder Filling Text by Ro McGonegal Photography by Moore Good Ink Jon Kaase keeps his eyes peeled. Over the years, the engine builder has seen an endless string of improvements and aftermarket components visited upon the Windsor 302 but he was woefully aware that there were no real advancements beyond the original cylinder head configuration. He thought he could produce castings that looked like ordinary Windsor 302/351 parts on the outside but would be entirely different from the original blueprint on the inside. As a racer, he knew the value of stealth. But more importantly as an engine builder he knew the prime advantages of canting the valves to lean towards the center of the cylinders and so mitigate the natural shrouding effect of the cylinder wall.Kaase designed the P38 cylinder head primarily for the 302W (8.2-inch deck height, 4×3 bore/stroke, 5.095-inch rods); its derivative the popular 347ci (over bored by 0.030-inch and stroke increased to 3.400-inch); the 351W (9.5-inch deck height, 4×3.5 bore/stroke, 5.960-inch rods), and the 427-454W Sportsman-type Dart block (9.5-inch deck height with 2.750-inch Cleveland main journals). Typical combustion chamber volume is 60-62cc.To insure optimum cylinder filling, Kaase canted the valves at 8×4.5 degrees on the intake and 10×4 degrees on the exhaust. The fresh area created by the new valve angles allowed an increase in the diameter of the valve heads to 2.100 inches and 1.60 inches.Astute CNC porting would induce far superior air flow and cylinder filling compared with any conventional layout and it accomplished two things: the revised angles place the intake valve...