Inside This Rat Rod’s Jon Kaase-built Pro Stock Engine

Although this radical ’28 Model A sedan has been around for about a couple years and is familiar to YouTube viewers, not much is known about the Jon Kaase-built 820ci mountain motor that overwhelms the original steel body with its factory brushed-on black paint. You see, information about Kaase’s race-engine program doesn’t flow easily out of the Georgia-based shop, however, be assured that this is a race engine.

“It’s pretty much a Pro Stock engine,” confirms Kaase. “Actually, he’s doing a little more street use than we thought he would.”

Kaase started with a Dart billet block with 5-inch bore spacing and a “small cooling system.” The 4.78-inch cylinders were stuffed with Diamond pistons that ride on top of BME rods and transfer power to a Sonny Bryant 5.75-inch stroke crankshaft. Compression ratio is a healthy 17:1, so race gas is required, even on the street runs. Lubrication and pan vacuum are provided by a Moroso 5-stage dry-sump system.

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The heads started out as C&C Motorsports hemi castings, then Kaase’s crew went to work with the CNC program. On top, Kaase built the induction around a HRE sheet-metal intake manifold and four Braswell 2-barrel carbs that boasts huge 2.5-inch throttle bores.

Cam timing is well-guarded secret, but EngineLabs managed to pry one spec out of Kaase: “It’s got an inch-two-fifty valve lift.”

Rounding out the engine build are an MSD ignition and 2 5/8-inch headers. Conservatively, the engine is worth 1,900 horsepower and 1,600 lb-ft of peak torque.

Owned by former Pro Stock racer Robert Killian, the car is built with a race-legal chassis and rollcage. It’s run in the low 8s at close to 200mph.

“And he’s never really left hard,” adds Kaase. “It’s missing about a full second of ET leaving the line.”