Due to the EU’s Global Data Protection Regulation, our website is currently unavailable to visitors from most European countries. We apologize for this inconvenience and encourage you to visit www.motortrend.com for the latest on new cars, car reviews and news, concept cars and auto show coverage, awards and much more.MOTORTREND.COM
 |   |   |  Diamond Rebel Series Honda Pistons - Rebel Yell
Subscribe to the Free

Diamond Rebel Series Honda Pistons - Rebel Yell

Behind the Machines of Diamond Pistons' 1,000+HP Rebel Series Honda Pistons

Evan Perkins
May 21, 2018

Horsepower comes in all shapes, sizes, and cylinder counts. But for the import inclined, making big power inevitably requires more robust engineering. Unlike a big V8 that spreads the loads over 8 pistons, a high-strung 4 cylinder needs extreme cylinder pressure and rpm to make the number. It's an Everest-sloped challenge, but one that has no shortage of willing contenders and checkered flags on the summit.

Turbos, nitrous, and superchargers do a "too-easy" job of providing the necessary power boost to run the number. However, getting that horsepower through the engine, transmission, and chassis is the black magic that separates first and second place. Diamond Pistons has long been a supporter of import racing and stood at the front line as FWD-class e.t.s saw 12s, 10s... and now times as quick as 7s in the 1/4 mile! As e.t.s continue to drop, they've used their considerable engineering experience to build pistons able to take unending racing abuse.

Building a piston to live with over 1,000hp in a 4-cylinder application—a bare minimum in today's racing environment—takes considerable skill. It also, historically, required a custom-made piston that took several iterations of development and testing to get right. The latter is no longer the case. Diamond's new Rebel Series pistons are the first shelf-stock Honda pistons ready for quadruple-digit power—and they have quite the racing pedigree.

  |   The Rebel Series Pistons combine Diamond's decades of import racing and engineering experience into one readily available piston ready to take the abuse.

Following in the lineage of the LS2k program (a shelf-stock piston for LS engine applications ready for 2,000hp), the Rebel series combines years of race-derived knowledge and a host of high-end features and packages it into a shelf-stock design. This cuts down on lead time tremendously for engine builders and racers alike.

"This is the first high-horsepower Honda product to market that's sold as a shelf part like this," said Dan Fonz, Sales and Technical Support Specialist at Diamond. "The pistons themselves are spec'd for 1,000-plus horsepower and include Tool Steel pins with a total seal ring pack. That's a steel top ring, steel napier second and a 2.8mm oil ring. We wanted to use high-quality components that could deliver right out of the box."

In addition to the high-end Total Seal ring pack, Rebel series pistons play host to several racing derived features such as lateral gas ports, to increase ring seal, and oil retention grooves which keep a reserve of oil just under the oil ring to help the piston effortlessly glide in and out of the bore at high rpm.

"These are built to the hilt as far as what Diamond can offer in a forging," said Fonz. "You've got to get the oil out of the hole when you're turning RPM like these guys do. That oil retention groove helps keep oil on the skirts and helps it glide in and out of the bore. It's a feature you see a lot on Pro Mod pistons but we went ahead and added it onto these. And, those lateral gas ports combined with the steel top rings are going to help seal with 40-50 pounds of boost."


  • Dedicated Forging (stronger than billet)
  • Lateral Gas Ports
  • .220in Thick Crown
  • .160in Thick Skirt
  • Total Seal Stainless Steel Top Ring, Steel Napier second ring and 2.8mm oil ring
  • Oil Retention Groove
  • Trend Tool Steel Wrist Pins
  • Forced Pin Oiling
  • Wrist Pin Buttons
  • Center balanced


The Rebel series draws from Diamond's experience in all forms of motorsports, but one of the main takeaways from previous drag racing endeavors was to put adequate material in the right places for the desired power level. "We spent the time to put the thicknesses in the right places, we 3D radiused everything," said Fonz. "It's a premium part and you know that when you pull it out of the box. First and foremost, the top ring lands are as thick as possible to be able to take the heat," "The material has to be thick and sturdy there and support that top ring and make sure there's no collapse. With the RPM and the boost levels these guys run you absolutely need that-it's crucial."

  |   Part of the Rebel's strength comes from its full-round skirt design and dedicated 2618 aluminum forging.
  |   In order to survive at over 1,000hp, the Rebel series uses extremely thick ring lands. Lateral gas ports are also incorporated to improve ring seal with high boost pressure.

The full round forging design is also a key to the Rebel's rigid design. "You see full round in a lot of higher horsepower stuff—anything full-on drag race, Pro Mod, Top Fuel—all of those guys are running full round. When you combine that with a Tool Steel pins and pin buttons, there's no movement, or travel. A lock isn't going to fall out if there's any type of stress."

  |   All Rebel Series Pistons use wrist pin buttons instead of conventional spiro locks. Pin buttons provide more support to the ring lands as well as eliminate the possibility of lock failure in extremely high cylinder pressure situations.

A full round forging rigidly bolsters the circumference of the piston, and also features a wider pin to help spread out the load of high cylinder pressure. That skirt shape, combined with the strength of the Rebel's dedicated 2618 aluminum forging and Tool Steel wrist pin are major factors in its quadruple-digit horsepower carrying capacity. But another detail that makes it ideally suited to high-revving Honda applications is full center balancing.

  |   Rebel pistons are fully machined to ensure material, weight, and strength are maximized. Crown and ring lands are exceptionally thick to take the heat 1,000-plus horsepower creates.

"Having a piston that's heavier on one side than the other, it's always going try to rock over in the bore," said Fonz. "When the piston is center balanced it goes up and down the bore easier, from a harmonics standpoint alone. At the 10,000-plus rpm these guys are turning, it's essential."


The Rebel Series will be available for both K- and B-series Honda engines in a range of compression ratios and compression heights-all designed for extreme horsepower applications. "We've had great success with the B series," said Fonz. "The B gets a lot of love. We've been thinking it was going to die off for 10 years, but it hasn't. People are still building them—there's a lot of great combinations out there. But there is going to be a demand for high-horsepower K-series engines. It's where the market is going to end up swinging, so we wanted to be prepared for when that happens. We're really shooting for the sport front-wheel drive community—teams that are looking to make all the horsepower they can to be competitive."

  |   The Rebel Series will be available for B and K series engines in popular bore and stroke considerations. They are compatible with all-out race engines and high-horsepower street engines alike.

Despite the Rebel's race derived design, it is 100 percent compatible with high-horsepower street cars, as well. "There're a lot of guys out there, especially in the K series market, getting into that 700-800hp range where they maybe need something a little bit more," said Fonz. "This is the piston for that. The parts really speak for themselves. When someone picks up one of these pistons and they look at the bottom side of it, and the structure and design, they can immediately tell this is a fully engineered and properly machined part ready to make power."

By Evan Perkins
6 Articles



The Sleepers Speed Shop crew dissected several factory and aftermarket shifters and have developed a solution which makes a significant impact on shift throws and shifter rigidity and does so without any modifications to the car's cabin or underside.
RodrezJul 19, 2019
The Wilwood ProHub is an attractive, lightweight, and fully serviceable forged aluminum racing hub for the 1990-2005 Mazda MX-5 Miata
Bob HernandezJul 18, 2019
Project Overland GR WRX now has a bit more growl and her engine is a bit more rev happy—thanks, SPEC and Borla!
Zach MartinJul 11, 2019
In part 1, we laid out the scenario of why Tommy Fitzgibbon's van needed saving and how that would get done. For part 2, we see how the build came together
Bob HernandezJul 3, 2019
Some fresh new carbon fiber bits for our Week2Wicked S2000 courtesy of Seibon and Evasive Motorsports.
RodrezJul 1, 2019
Join Our FREE

Sign Up today for our FREE Newsletter and get the latest articles and news delivered right to your in-box.

Sponsored Links



обращайтесь imr.net.ua

У нашей компании авторитетный web-сайт , он рассказывает про www.teplostroy.biz.ua.