FSR (Forged Side Relief) forging designs feature a reduced skirt width and shorter wrist pin when compared to traditional “full round” style forgings. The narrow skirt helps minimize piston contact with the cylinder wall that can cause friction and power loss while the shortened wrist pins reduces the overall weight. Some FSR forgings feature internal and external bracing to provide a more rigid construction while minimizing overall weight. With thousands of race miles logged in the most demanding applications like NASCAR, NHRA Pro Stock and Indy Car, these pistons provide the ultimate combination of low-friction, lightweight design with increased stability and strength.
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Over 75 Years of Piston Manufacturing Experience
Over 75 Years of Piston Manufacturing Experience
JE has been at the forefront of custom forged racing piston technology for over 75 years with experience in every aspect of racing and engine platform. Whether it’s a fun LS build, and all-out drag race engine, a boosted four-cylinder, a powersports machine, or anything in between, JE can bring your dream pistons to reality.
- Forged or billet construction
- Designed specifically for you to achieve your power and durability goals
- Many coatings treatments are available – skirt coating, crown coatings, ring grooves, and pin bore anodizing and plating, and more.
- Dozens of custom performance features available – 3D milling, gas porting, accumulator and contact reduction grooves, pin oiling, and more
We have hundreds of popular block and head combinations on file to make your order even easier!
Find our custom piston order form below and contact our team to get started.
For decades, JE Pistons has manufactured custom pistons for thousands of applications. JE Piston’s in-house engineering and manufacturing centers can produce a custom piston for almost any 4-stroke engine. To order custom pistons, please use the Custom Piston Order Form. You can download one here. Custom pistons do not include pins, locks, or rings. Please see the components section of this page to select the proper components for your custom order.
JE has been at the forefront of custom forged racing piston technology for over 75 years with experience in every aspect of racing and engine platform. Whether it’s a fun LS build, and all-out drag race engine, a boosted four-cylinder, a powersports machine, or anything in between, JE can bring your dream pistons to reality.
- Forged or billet construction
- Designed specifically for you to achieve your power and durability goals
- Many coatings treatments are available – skirt coating, crown coatings, ring grooves, and pin bore anodizing and plating, and more.
- Dozens of custom performance features available – 3D milling, gas porting, accumulator and contact reduction grooves, pin oiling, and more
We have hundreds of popular block and head combinations on file to make your order even easier!
Find our custom piston order form below and contact our team to get started.
For decades, JE Pistons has manufactured custom pistons for thousands of applications. JE Piston’s in-house engineering and manufacturing centers can produce a custom piston for almost any 4-stroke engine. To order custom pistons, please use the Custom Piston Order Form. You can download one here. Custom pistons do not include pins, locks, or rings. Please see the components section of this page to select the proper components for your custom order.
Applications Include:
Applications Include:
Alfa Romeo
AMC
Aston Martin
Audi
Austin Healey
Bentley
BMW
BSA
Buick
Cadillac
Caterham
Chevrolet
Chrysler
Citroen
Cosworth
Datsun
Dodge
Ducati
Ferrari
Fiat
Ford
Harley Davidson
Holden
Honda
Husqvarna
Indian
Isuzu
Jaguar
Jeep
Kawasaki
KTM
Lamborghini
Lotus
Maserati
Mazda
Mercedes Benz
Hyundai
MG
Mitsubishi
Moto Guzzi
Noble
Oldsmobile
Opel
Peugeot
Plymouth
Pontiac
Porsche
Radical
Renault
Rolls Royce
Saab
Skoda
Smart
Subaru
Toyota
Triumph
Vauxhall
Volvo
VW
Yamaha
and more…
Alfa Romeo
AMC
Aston Martin
Audi
Austin Healey
Bentley
BMW
BSA
Buick
Cadillac
Caterham
Chevrolet
Chrysler
Citroen
Cosworth
Datsun
Dodge
Ducati
Ferrari
Fiat
Ford
Harley Davidson
Holden
Honda
Husqvarna
Indian
Isuzu
Jaguar
Jeep
Kawasaki
KTM
Lamborghini
Lotus
Maserati
Mazda
Mercedes Benz
Hyundai
MG
Mitsubishi
Moto Guzzi
Noble
Oldsmobile
Opel
Peugeot
Plymouth
Pontiac
Porsche
Radical
Renault
Rolls Royce
Saab
Skoda
Smart
Subaru
Toyota
Triumph
Vauxhall
Volvo
VW
Yamaha
and more…
PISTON TERMINOLOGY
PISTON TERMINOLOGY
With over 300 individual forgings to choose from, JE is able to achieve specific piston design requirements while reducing overall weight.
With over 300 individual forgings to choose from, JE is able to achieve specific piston design requirements while reducing overall weight.
FSR (Forged Side Relief) forging designs feature a reduced skirt width and shorter wrist pin when compared to traditional “full round” style forgings. The narrow skirt helps minimize piston contact with the cylinder wall that can cause friction and power loss while the shortened wrist pins reduces the overall weight. Some FSR forgings feature internal and external bracing to provide a more rigid construction while minimizing overall weight. With thousands of race miles logged in the most demanding applications like NASCAR, NHRA Pro Stock and Indy Car, these pistons provide the ultimate combination of low-friction, lightweight design with increased stability and strength.
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Round
Round with Full Sidemill
FSR With External
Internal and External
Braced FSR
Round
Round with Full Sidemill
FSR With External
Internal and External
Braced FSR
STANDARD PISTON FEATURES
STANDARD PISTON FEATURES
- Fully CNC Machined Piston
- Precision Machined CNC Ring Grooves
- 2618 Low-Silicon or optional 4032
High Silicon material available on some applications
- Diamond Turned Skirts
- Radiused Valve Reliefs
- Single Forced Pin Oilers
- Pick Lock Grooves (for use with wire locks)
- Machined Side Reliefs on full round forgings
- Lock Grooves Machined for Carbon Steel Spiro Locks
(other options available) - Engineered for your application!
- Fully CNC Machined Piston
- Precision Machined CNC Ring Grooves
- 2618 Low-Silicon or optional 4032
High Silicon material available on some applications
- Diamond Turned Skirts
- Radiused Valve Reliefs
- Single Forced Pin Oilers
- Pick Lock Grooves (for use with wire locks)
- Machined Side Reliefs on full round forgings
- Lock Grooves Machined for Carbon Steel Spiro Locks
(other options available) - Engineered for your application!
Ultra Crown Dome / Inverted Dome: The Ultra Crown machining process allows incredibly precise dome to cylinder head tolerances. By mapping the exact shape of a piston or cylinder head, optimum compression and quench characteristics can be achieved.
3D Under Crown Milling: The Under Crown machining process allows for uniform deck thickness, therefore creating a lighter and more durable piston.
Vertical Gas Ports: Vertical holes in the deck of the piston, allows combustion pressure to directly enter behind the top ring on the power stroke, thus pressurizing the area behind the top ring for greater ring to cylinder wall seal. During the rest of the cycle, the ring has normal tension for reduced friction. (Most commonly used for drag race applications).
Lateral Gas Ports: This process mills slots into the top of the top ring groove and provides a pathway for combustion pressure to get behind the top ring. This process helps to increase ring seal and is most common in circle track applications.
Ultra Groove: Ultra Groove is a special ring groove machining process that provides near perfect groove flatness and surface finish. Tolerances are held to millionths of an inch.
Pin Boss & Window Milling: In certain applications window milling will remove a significant amount of weight from the skirt of the piston while maintaining its strength and integrity. Spin Boss refers to machining on the bottom of the pin boss, which removes weight where it is not needed for strength.
Plunge Boss & Chamfer Pin Boss: Machining process that removes additional material for added weight savings.
Contact Reduction Grooves: The purpose of machining these grooves is to reduce the amount of contact area against the cylinder wall when the piston “rocks over”. Contact reduction also serves to disrupt the flame travel into the crevice area thus helping to reduce detonation.
Accumulator Grooves: An accumulator groove is machined into the land between the top and second ring. It provides additional volume where residual combustion gases that have “blown by” the top ring can collect. This additional volume helps to reduce pressure between the top & second ring, thus aiding in top ring seal and minimizing ring flutter.
Double Pin Oilers: Double Pin Oilers deliver twice the amount of oil to the wrist pin as compared to the standard single pin oiler.
Pin Fitting: The pin bore is precision honed to attain an exact pin clearance. Clearances typically range from .0003 to .0010 between the wrist pin and pin bore.
Oil Squirt Notch: Notching can be done on pistons for motors with oil squirters, or to avoid contact between pistons and/or pistons and crankshaft.
Bottom Oilers: This process machines one or two holes into the bottom of the pin boss to assist in splash pin lubrication.
Tulip Valve Pockets: Most commonly used on Hemi and motorcycle engines, this process leaves a raised area on plunged valve pockets to achieve maximum compression.
Ultra Crown Dome / Inverted Dome: The Ultra Crown machining process allows incredibly precise dome to cylinder head tolerances. By mapping the exact shape of a piston or cylinder head, optimum compression and quench characteristics can be achieved.
3D Under Crown Milling: The Under Crown machining process allows for uniform deck thickness, therefore creating a lighter and more durable piston.
Vertical Gas Ports: Vertical holes in the deck of the piston, allows combustion pressure to directly enter behind the top ring on the power stroke, thus pressurizing the area behind the top ring for greater ring to cylinder wall seal. During the rest of the cycle, the ring has normal tension for reduced friction. (Most commonly used for drag race applications).
Lateral Gas Ports: This process mills slots into the top of the top ring groove and provides a pathway for combustion pressure to get behind the top ring. This process helps to increase ring seal and is most common in circle track applications.
Ultra Groove: Ultra Groove is a special ring groove machining process that provides near perfect groove flatness and surface finish. Tolerances are held to millionths of an inch.
Pin Boss & Window Milling: In certain applications window milling will remove a significant amount of weight from the skirt of the piston while maintaining its strength and integrity. Spin Boss refers to machining on the bottom of the pin boss, which removes weight where it is not needed for strength.
Plunge Boss & Chamfer Pin Boss: Machining process that removes additional material for added weight savings.
Contact Reduction Grooves: The purpose of machining these grooves is to reduce the amount of contact area against the cylinder wall when the piston “rocks over”. Contact reduction also serves to disrupt the flame travel into the crevice area thus helping to reduce detonation.
Accumulator Grooves: An accumulator groove is machined into the land between the top and second ring. It provides additional volume where residual combustion gases that have “blown by” the top ring can collect. This additional volume helps to reduce pressure between the top & second ring, thus aiding in top ring seal and minimizing ring flutter.
Double Pin Oilers: Double Pin Oilers deliver twice the amount of oil to the wrist pin as compared to the standard single pin oiler.
Pin Fitting: The pin bore is precision honed to attain an exact pin clearance. Clearances typically range from .0003 to .0010 between the wrist pin and pin bore.
Oil Squirt Notch: Notching can be done on pistons for motors with oil squirters, or to avoid contact between pistons and/or pistons and crankshaft.
Bottom Oilers: This process machines one or two holes into the bottom of the pin boss to assist in splash pin lubrication.
Tulip Valve Pockets: Most commonly used on Hemi and motorcycle engines, this process leaves a raised area on plunged valve pockets to achieve maximum compression.
PISTON COATINGS
PISTON COATINGS
Thermal Barrier Crown Coating
Applied to the top of the piston and is designed to reflect heat into the combustion chamber, thereby increasing exhaust gas velocity and greatly improving scavenging potential. The .0015” thick coating can also assist in extending piston life by decreasing the rate of thermal transfer.
TUFF SKIRT ® Coating
JE Pistons’ trademark coating that is a lubricating, anti-friction/anti-wear coating applied to the piston skirt only. Unlike our standard Skirt Coating, Tuff Skirt will not wear and is designed to withstand many different types of endurance applications, similar to those commonly found in NASCAR. Buildup is .0005” per surface and finished diameter of skirt should include the coating buildup.
Anodized Ring Groove Coating
Reduces wear and material transfer between the ring and groove. Shown to be very durable in maximum effort, high endurance applications. Appropriate manufacturing allowances apply.
Thermal Barrier Crown Coating
Applied to the top of the piston and is designed to reflect heat into the combustion chamber, thereby increasing exhaust gas velocity and greatly improving scavenging potential. The .0015” thick coating can also assist in extending piston life by decreasing the rate of thermal transfer.
TUFF SKIRT ® Coating
JE Pistons’ trademark coating that is a lubricating, anti-friction/anti-wear coating applied to the piston skirt only. Unlike our standard Skirt Coating, Tuff Skirt will not wear and is designed to withstand many different types of endurance applications, similar to those commonly found in NASCAR. Buildup is .0005” per surface and finished diameter of skirt should include the coating buildup.
Anodized Ring Groove Coating
Reduces wear and material transfer between the ring and groove. Shown to be very durable in maximum effort, high endurance applications. Appropriate manufacturing allowances apply.
KoolKote
Is an aerospace quality hard anodize applied to all surfaces of the piston with a buildup of .001. This coating is designed for use in nitro-methane engines such as Top Fuel Drag Racing to endure the corrosive effects of this type of fuel. It will withstand greater temperatures and will not flake, chip or peel. This coating does alter the heat transfer and expansion characteristics of the piston. Consult the JE Pistons technical department for specific applications. Manufacturing allowances are required on all surfaces.
Perfect Skirt™
Perfect Skirt is a proprietary and patented skirt coating only offered by JE Pistons. Perfect Skirt is three-times thicker than traditional skirt coatings to allow racing pistons to have tighter piston-to-wall clearances similar to OEM applications. This decreases piston noise on startup and reduces cylinder bore wear. Additionally, this is beneficial for late-model engines, reducing the possibility of false knock sensor readings. Perfect Skirt will continuously conform to the shape of your cylinder’s bore.
EN Plating
Help reduce pitting and piston ring micro welding caused by detonation with JE’s Electroless Nickel plating. Unlike other metal plating that loses hardness and softens when exposed to heat, Electroless Nickel gets harder as it runs. The plating is applied to the piston domes, ring grooves, and wrist pin bore to provide a lower coefficient of friction, reduce ring blow-by, and increase detonation protection. In addition, Electroless Nickel reflects heat and allows domes to run up to 68 degrees cooler.
KoolKote
Is an aerospace quality hard anodize applied to all surfaces of the piston with a buildup of .001. This coating is designed for use in nitro-methane engines such as Top Fuel Drag Racing to endure the corrosive effects of this type of fuel. It will withstand greater temperatures and will not flake, chip or peel. This coating does alter the heat transfer and expansion characteristics of the piston. Consult the JE Pistons technical department for specific applications. Manufacturing allowances are required on all surfaces.
Perfect Skirt™
Perfect Skirt is a proprietary and patented skirt coating only offered by JE Pistons. Perfect Skirt is three-times thicker than traditional skirt coatings to allow racing pistons to have tighter piston-to-wall clearances similar to OEM applications. This decreases piston noise on startup and reduces cylinder bore wear. Additionally, this is beneficial for late-model engines, reducing the possibility of false knock sensor readings. Perfect Skirt will continuously conform to the shape of your cylinder’s bore.
EN Plating
Help reduce pitting and piston ring micro welding caused by detonation with JE’s Electroless Nickel plating. Unlike other metal plating that loses hardness and softens when exposed to heat, Electroless Nickel gets harder as it runs. The plating is applied to the piston domes, ring grooves, and wrist pin bore to provide a lower coefficient of friction, reduce ring blow-by, and increase detonation protection. In addition, Electroless Nickel reflects heat and allows domes to run up to 68 degrees cooler.
HOW TO ORDER YOUR CUSTOM PISTONS
HOW TO ORDER YOUR CUSTOM PISTONS
JE has the fastest lead time in the industry on custom pistons, but there are a few ways to make your custom piston experience even quicker! Check out these simple tips that could save tons of time!
Tips To Speed Up Your Custom Piston Order!
No one enjoys waiting. From those excruciating last ticks of the elementary school-clock, to the lull in between adult pay days; now always trumps later. Custom pistons are no exception, and at JE we have pushed hard to cultivate the fastest custom lead time in the industry. But there are a few simple ways to make the custom process even quicker.
How Custom Is Your Custom?
“Custom piston” can be a somewhat ambiguous term. For example, a 1930s Bugatti piston and a small-block Chevy with an extra-thin ring pack are both technically custom pistons. Obviously, one will require a significant amount more engineering work than the other. For this reason, JE offers what’s known as a "One Change to Shelf Part" that can adjust pre-existing shelf pistons. These changes, such as a slightly bigger or smaller bore size, different ring pack dimensions, or the addition of gas ports allows builders to customize pistons to their application, without starting from scratch and with minimal cost.
If there is a pre-existing shelf part that is close to a desired custom, referencing that at time of order also can save substantial engineering time. Now, should no suitable piston architecture exist for your application, JE can machine one from scratch out of our forging library, or in certain cases, a forged billet.
The very first step of the custom piston process is choosing the base, forged-aluminum material the piston will be machined from. Knowing your intended application and as much as possible about your intended usage is key to building the perfect piston.
From Scratch or Reorder?
In racing and some high-horsepower street applications, pistons are a wear item and are often replaced at the end of the season(s), or during rebuilds. If your engine already has a set of custom JEs, we haven’t forgotten how to make them! JE keeps a huge archive of all our previous custom jobs and referencing the part number/job number can save you tons of time in getting another set for your racing program.
Do Your Homework
The first question that should be asked when selecting a piston is “What am I trying to accomplish?” Is the goal to reduce weight, increase strength, or accommodate a stroker crankshaft or longer connecting rod? In real estate, the key phrase is “location,” but in the world of custom pistons, it’s “application.”
Determining what you intend to do with the piston is paramount to proper design, beginning even with the base material the piston is machined from. Having a goal for your piston early on is key.
If your engine already has a set of JE Pistons, identifying them via the part or job number is a great way to speed up delivery of a new set.
The very first step of the custom piston process is choosing the base, forged-aluminum material the piston will be machined from. Knowing your intended application and as much as possible about your intended usage is key to building the perfect piston.
From Scratch or Reorder?
In racing and some high-horsepower street applications, pistons are a wear item and are often replaced at the end of the season(s), or during rebuilds. If your engine already has a set of custom JEs, we haven’t forgotten how to make them! JE keeps a huge archive of all our previous custom jobs and referencing the part number/job number can save you tons of time in getting another set for your racing program.
Do Your Homework
The first question that should be asked when selecting a piston is “What am I trying to accomplish?” Is the goal to reduce weight, increase strength, or accommodate a stroker crankshaft or longer connecting rod? In real estate, the key phrase is “location,” but in the world of custom pistons, it’s “application.”
Determining what you intend to do with the piston is paramount to proper design, beginning even with the base material the piston is machined from. Having a goal for your piston early on is key.
If your engine already has a set of JE Pistons, identifying them via the part or job number is a great way to speed up delivery of a new set.
Depending on the level of complexity, application, and desired piston crown style, it may be necessary to send a sample piston and/or cylinder head to JE’s engineering lab.
Common Application Info You Should Have Ready:
- Does the engine have a supercharger, turbocharger, or nitrous?
- How much horsepower do you intend to make?
- How high does the engine rev?
- How long is the crankshaft stroke?
- How long are your connecting rods?
- What is the deck height of the block?
- What compression ratio are you looking for?
The Custom Form
A piston interacts with every critical internal engine component around it in some way. For that reason, JE has created an extremely extensive custom piston order form that takes into account crankshaft, connecting, rod and valvetrain measurements, as well as several other critical factors. Having this form filled out as thoroughly as possible is a key step in ordering custom pistons, and can majorly springboard the process.
Depending on the level of complexity, application, and desired piston crown style, it may be necessary to send a sample piston and/or cylinder head to JE’s engineering lab.
Common Application Info You Should Have Ready:
- Does the engine have a supercharger, turbocharger, or nitrous?
- How much horsepower do you intend to make?
- How high does the engine rev?
- How long is the crankshaft stroke?
- How long are your connecting rods?
- What is the deck height of the block?
- What compression ratio are you looking for?
The Custom Form
A piston interacts with every critical internal engine component around it in some way. For that reason, JE has created an extremely extensive custom piston order form that takes into account crankshaft, connecting, rod and valvetrain measurements, as well as several other critical factors. Having this form filled out as thoroughly as possible is a key step in ordering custom pistons, and can majorly springboard the process.
Be Prepared to Send a Sample
In certain cases, a custom piston form, as extensive as it is, won’t paint the full picture of the complex dimensions required on an automotive piston. If your piston has a dome profile, is an unusual shape, or hails from an uncommon engine platform, it’s a good idea to have a factory sample ready to send in. JE has a full engineering lab in their Cypress, CA facility that specializes in reverse engineering and redesigning pistons for both automotive and powersports applications. We can even scan a cylinder head, creating a 3D combustion chamber model, if a complex piston dome profile is required. Also, if you don’t have the precision measuring tools, to confidently fill out your custom order form, we can help gather that data.
When Time is Tight, Expedite
While JE consistently offers the fastest production time in the industry, there is also a unique expedite program in place to grease the engineering and production wheels for individuals and teams on a tight timeline. We offer a Red & Blue expedite (Please see order form for details) which is available at an additional charge when time is of the essence.
The Road to Customs
The above is the quickest way to a set of custom pistons. Race Winning Brands Europe employs a full team of technical sales experts to help walk you through this technically-biased process. If you aren’t sure what you need and could use a hand deciphering the sea of part numbers, measurements, and other performance data, ordering a set of custom pistons begins with nothing more than a simple phone call.
JE has a unique expedite process in place to help teams and individuals that need lightning-quick delivery. They also have a vast array of technologies such as rapid prototyping that help speed up the manufacturing process.
Be Prepared to Send a Sample
In certain cases, a custom piston form, as extensive as it is, won’t paint the full picture of the complex dimensions required on an automotive piston. If your piston has a dome profile, is an unusual shape, or hails from an uncommon engine platform, it’s a good idea to have a factory sample ready to send in. JE has a full engineering lab in their Cypress, CA facility that specializes in reverse engineering and redesigning pistons for both automotive and powersports applications. We can even scan a cylinder head, creating a 3D combustion chamber model, if a complex piston dome profile is required. Also, if you don’t have the precision measuring tools, to confidently fill out your custom order form, we can help gather that data.
When Time is Tight, Expedite
While JE consistently offers the fastest production time in the industry, there is also a unique expedite program in place to grease the engineering and production wheels for individuals and teams on a tight timeline. We offer a Red & Blue expedite (Please see order form for details) which is available at an additional charge when time is of the essence.
The Road to Customs
The above is the quickest way to a set of custom pistons. Race Winning Brands Europe employs a full team of technical sales experts to help walk you through this technically-biased process. If you aren’t sure what you need and could use a hand deciphering the sea of part numbers, measurements, and other performance data, ordering a set of custom pistons begins with nothing more than a simple phone call.
JE has a unique expedite process in place to help teams and individuals that need lightning-quick delivery. They also have a vast array of technologies such as rapid prototyping that help speed up the manufacturing process.
THE CUSTOM ORDER FORM
THE CUSTOM ORDER FORM
Click the button below to go to the form. Fill in all fields (highlighted fields are required fields). Email it to automotive@rwbteam.eu. Once your form is received, a Customs Specialist will contact you to prepare your order.
Click the button below to go to the form. Fill in all fields (highlighted fields are required fields). Email it to automotive@rwbteam.eu. Once your form is received, a Customs Specialist will contact you to prepare your order.