Bringing You The Recipe

If you didn't already know, Hoonigan: Project Cars has been building a K24 over the past few months with one goal in mind: 10,000 RPM. This engine was also being built as a giveaway to one lucky winner from the Hoonigan viewership. Suppy and the team stopped in for the final leg of the build to have us do some tuning to see if we could reach that 10K goal.

Well, we got them there with the addition of some Skunk2 parts and we are finally here to tell you the results! Just in case you haven't seen the original video and want to get up to date, take a quick look:

 

 

Build List:

• • Skunk2 Ultra Race Intake Manifold
• • Skunk2 K series Composite Fuel Rail
• • Skunk2 Black Anodized K series Timing Chain Cover
• • Skunk2 Pro K Series Exhaust Cam Gear
• • Skunk2 Valve Cover Hardware
• • Grams Performance 750cc K Series Fuel Injectors
• • 4 Piston 156v2 CNC Cylinder Head
• • Ferrea 6000 Valves and Valvetrain
• • Originally: 4 Piston RR3 K Series Camshafts (See below for camshaft info!)
• • New Valve Seals and Valve Guides
• • Wiseco 87.5mm 11.0:1 Pistons
• • Manley K24 H-Beam Rods
• • King Race Main and Rod Bearings
• • ATI Street Damper
• • ARP Head Studs
• • Hondata Intake Manifold Gasket
• • K-Tuned Oil Pan with Hardware
• • K-Tuned Swivel Thermostat Housing
• • K-Tuned Timing Tensioner

 

More Flavor Needed

This engine was the creation of Suppy himself, taking the time to pick the right parts for what he wanted to achieve. Once we got the engine properly secured to our in-house SuperFlow engine dyno, it was clear that this K was out for blood! Making great power all the way to redline, it sounded crisp and had a great torque curve with plenty of usable power. But, at the end of day one, one thing was clear: that redline definitely wasn't 10,000 rpm.

"We promised you 10k, we're gonna give you 10k!" - Suppy

In order to reach the goal, Skunk2 Founder Dave Hsu was brought in to provide a solution to get the engine where it needed to go. Dave worked out the compression ratio and remaining details of the build and decided the engine needed a bigger cam set plus a few extras. That evening, Dr. Charles and Daniel ripped the top end apart and added the upgrades.

 

The Secret Sauce

A few changes were made that evening, including the addition of our Skunk2 Black Anodized K series Timing Chain Cover and Skunk2 Pro K Series Exhaust Cam Gear. Details on these components can be found on our previous article as well as the related product pages.

The biggest hang up keeping the engine from reaching the RPM goal came down to the choice of camshafts that were used in the build. The supplied 4Piston RR3 camshafts simply were not designed to a specification that would support this specific build to 10,000 rpm. Dave's calculations pointed to a limitation in airflow which was causing the engine to struggle for air at anything above 9000 rpm.

It was with this insight that the decision was made to swap them out for a set of our Skunk2 K Series Ultra 2 Camshafts. With precisely .557" intake and .535" exhaust lift plus 263 degrees of duration, these cams offered more than enough airflow for what the engine required.

 

Quick Camshaft Basics

There are many factors in selecting the proper camshaft for your build, let alone designing them as we have at Skunk2 for over two and a half decades.

"Simplest explanation, the higher the RPM, the more duration." - Dave Hsu, Skunk2 Founder

Not all engines are the same, therefore, not all camshaft requirements are the same; even at the same RPM. Proper lift and duration can be found by first determining the required CFM (cubic feet per minute) to fill a single cylinder's volume at a given RPM. There are formulas used to determine required CFM based off the engines measured bore, stroke, displacement, and maximum RPM. We'll break this down in a future, more in-depth cam tech article.

Keeping it simple, the goal is to have a duration and lift that is capable of flowing an even higher CFM than the engine requires. This allows the valves to bring all the air that is necessary to achieve the highest volumetric efficiency and thusly the highest horsepower.

 

Michelin Star Approved

Suppy and the boys returned the next day to properly spec'd engine ready to hit the dyno and make power. A last second header swap to add to the perfect mix of parts and we were off to the races. Within a few pulls it was clear, 10K was no longer a problem.

 

 

This engine is poised to put a grin on any enthusiasts face. Screaming up to 10,000rpm and begging for more, we pulled a quick 307.7hp and 208.7lb-ft of torque, nearly 10hp higher than with the previous cams.

Fitted with some of the highest quality parts from multiple manufacturers, we also fit our 1 of 1 prototype Magnesium Racing Valve cover powdercoated a candy red to finish off the build. Already off to the winner of the Hoonigan giveaway, this engine is a true collectors item.