Building & Proving a 427 LSX

KinG Certified Performance’s first custom camshaft project began as a design exercise and developed into a complete naturally aspirated 427 LSX engine program. The engine was assembled, mechanically verified, physically degreed, carbureted, calibrated and tested at R&R Racing in Evans, Louisiana on a SuperFlow 901 engine dyno.

From Education to a Camshaft Specification

John McClinton developed the JAM J Edition specification after working through numerous hypothetical combinations using knowledge gained through formal education in EFI calibration, airflow, combustion and engine operation. The objective was to produce a functional camshaft that could make legitimate power, retain a broad street-oriented powerband and still deliver the response and personality expected from a serious performance street car.

Duration, valve lift, lobe separation, intake centerline, overlap, displacement, cylinder-head airflow, compression ratio, street behavior and future power-adder use were considered before the specification was finalized. Cam Motion was selected to grind the physical camshaft to those specifications. From this point forward, it is simply referred to as our custom camshaft.

Lift Chosen Around the M311 Heads

The .650/.639 valve-lift combination was specifically selected to operate efficiently with the airflow characteristics of the Frankenstein M311 cylinder heads.

Instead of chasing additional valve lift simply to advertise a larger number, our custom camshaft was designed to use the cylinder head where it was already producing nearly all of its available high-lift airflow.

The 427 LSX Combination

The naturally aspirated development engine operated at approximately 10.2:1 compression. That moderate compression ratio is important context for the final power numbers: this combination was not relying on extreme static compression to create the result.

Building the Engine as a Team

Randy Jean and Nathan Jean handled major portions of the short-block assembly and preparation. Nathan’s influence extended well beyond any single photographed operation, with his attention to quality control, troubleshooting and repeated verification present throughout the project.

James Dixson worked alongside John McClinton during completion of the long-block assembly. McClinton personally torqued the Frankenstein M311 cylinder heads to specification while James assisted with bringing the long block together. James also contributed knowledge of carburetor tuning, MSD operation and valvetrain control, while playing an important role in bringing the collaboration together.

Degree It—Don’t Assume It

Randy Jean brought more than 25 years of engine-building experience to the project, much of it involving dirt-track engines that regularly operate under severe load, high rpm and often see the winner’s circle. When it came time to install our custom camshaft, Randy insisted that McClinton personally degree his own camshaft rather than simply watch someone else perform the process.

Randy supervised the procedure and made sure the measurements were accurate. The lesson extended beyond this one engine: if KCP was going to develop camshafts, the person specifying them needed to understand exactly where the lobes were installed and how the cam-card information translated into measured valve events.

Oil Pressure Under Load

The Melling M295HV oiling system proved itself during dyno testing. Recorded gasoline-run data showed approximately 70.5 psi at 4,100 rpm, 80.7 psi at 6,000 rpm and roughly 83.5 psi near 6,700 rpm. More than 82 psi remained at 7,100 rpm—effectively about 84 psi near the top of the pull.

R&R Racing—Evans, Louisiana

Final engine testing took place at R&R Racing using a SuperFlow 901 engine dyno. The dyno work remained collaborative. Randy Jean operated the SuperFlow controls. James Dixson operated the MSD system and applied the ignition changes McClinton wanted to evaluate while also contributing his carburetor knowledge. Nathan remained influential throughout the quality-control and verification process.

For McClinton, the project was also a valuable learning experience. Each person brought a different area of experience to the engine program, and that exchange of knowledge became as important as the final number.

93 Octane Baseline

The gasoline configuration used an ATM 950-cfm carburetor on the Edelbrock Victor Jr. intake. Final wide-open-throttle ignition timing was 27 degrees.

The Airflow Data

Air demand continued to increase even after peak horsepower, giving KCP a useful look at what the engine wanted on the top end.

Switching to Methanol

After the gasoline testing, James and Randy converted the engine to an 825-cfm Demon methanol carburetor. Final WOT ignition timing was increased to 29 degrees.

Compared with the documented gasoline result, the methanol combination gained approximately 26.6 horsepower and 29.0 lb-ft of torque.

More Than a Peak Number

The strongest result from this project was not simply 679.9 horsepower. It was the development process that produced it. A KCP camshaft specification moved from a theoretical combination to an actual ground camshaft, was installed in a real engine, physically degreed, supported by a carefully assembled rotating and valvetrain package, and then evaluated on two fuels under controlled dyno conditions.

The testing remained collaborative throughout. Randy’s decades of engine-building experience, James’s carburetor, ignition and valvetrain knowledge, Nathan’s broad influence across preparation and quality control, and McClinton’s willingness to learn from everyone involved made the project better than it would have been as an individual effort.