About Spool Conrods
About Spool Conrods
Since 2001, Spool conrods have been trusted by performance engine builders, racers and serious street car enthusiasts across Australia and around the world. Designed for strength, precision and value, Spool connecting rods are built for high-performance engines where reliability matters.
Don't Be a Fool. Insist on Genuine Spool.
Spool Imports offers a large range of performance connecting rods for popular import, domestic and high-output engine platforms. If a specific application is not currently listed, there is a good chance it is already in development.
Our conrods are stocked in Brisbane, Australia and are dispatched nationally and internationally, usually within 24 hours of receiving your order. International orders are generally sent by express air freight unless requested otherwise.
Spool conrods are engineered to deliver the strength, finish, sizing accuracy and value demanded by modern performance engine builds. They are used in everything from serious street cars through to high-power competition engines.
The Spool Conrod Range
Spool H-Beam Conrods
A proven performance rod for strong street, circuit, drag and boosted engine builds. Spool H-Beam rods are manufactured from high tensile 4340 forged steel and supplied with ARP2000 bolts as standard.
Spool Drag Pro I-Beam Conrods
Built for high-load applications where additional beam strength and larger fasteners are required. Drag Pro rods use a serious I-Beam design and larger 7/16 inch fasteners for demanding combinations.
Spool X300 I-Beam Conrods
The Spool X300 range is our extreme I-Beam conrod series, manufactured from 300M steel for high-end performance engine builds. X300 rods are designed for applications where strength, durability and premium material specification are critical.
Spool Conrod Features
Premium Materials
- High tensile 4340 forged steel on H-Beam and selected I-Beam models
- 300M steel material on Spool X300 conrods
- Two-piece forging construction on forged steel models
- Heat treated and quenched for strength and durability
Precision Manufacturing
- Dowelled cap design for accurate alignment
- Precision big-end sizing
- Silicon bronze small-end bushings
- Engineered cap and beam designs for stability under load
Quality Control
- X-ray and sonic testing
- Shot peened finish
- 100% Magnaflux inspection
- Hardness controlled to suit the application
Engineering Details
Lipped Cap and Lipped Cap Relief
In high-output engines, connecting rods are exposed to severe tensile loads. Spool's lipped cap design increases the contact area between the cap and the rod body, improving big-end integrity with minimal additional weight. This feature is especially valuable in extreme applications where stroke, piston weight and engine speed place significant load on the rod assembly.
Big-End Thrust Oil Squirters
Selected Spool rods include notches in the big-end thrust faces. These allow pressure-fed oil to be directed toward the piston and pin area, improving lubrication and assisting with cooling. This can be particularly useful in engines that do not have factory piston oil squirters.
Dowelled Cap Design
Dowelled caps help locate the rod and cap accurately as one assembly. This improves cap alignment and allows the fasteners to be positioned closer to the big-end bore, supporting big-end stability under demanding engine loads.
Aftermarket Forged Steel Construction
Performance connecting rods benefit from superior parent material, controlled machining and tighter tolerances compared with many original equipment rods. Spool forged rods use high-grade steel materials designed for performance applications where rpm, boost, cylinder pressure and engine load are significantly higher than factory operating conditions.
Why We Do Not Use Simple Horsepower Ratings
Spool is often asked for a single horsepower rating for each rod design. In practice, rod durability depends on more than horsepower alone. Engine speed, stroke, piston weight, boost pressure, cylinder pressure, fuel type, tuning quality and drivetrain shock all influence the load placed on a connecting rod.
A correctly selected rod should suit the complete engine combination, not just a target power number. For serious builds, we recommend choosing the rod design and fastener package based on the intended rpm range, power level, use case and engine platform.
Spool Conrods FAQs
What are Spool conrods made from?
Most Spool H-Beam and Drag Pro conrods are manufactured from high tensile 4340 forged steel. Spool X300 I-Beam conrods are manufactured from 300M steel for extreme high-performance applications.
Do Spool conrods come with ARP bolts?
Yes. All Spool conrods come standard with genuine ARP2000 fasteners. L19 bolt upgrades are available across the range, and CA625+ upgrades are available for selected H-Beam rods using 3/8 inch bolts.
What is the difference between Spool H-Beam, Drag Pro and X300 conrods?
Spool H-Beam rods are a proven forged 4340 steel rod for strong street and motorsport builds. Drag Pro rods are an I-Beam design for higher load applications and use larger 7/16 inch fasteners. Spool X300 rods are the extreme I-Beam range, manufactured from 300M steel for premium high-performance engine builds.
Are Spool conrods suitable for turbocharged engines?
Yes. Spool conrods are commonly used in turbocharged, supercharged, nitrous and high-compression naturally aspirated engines. The correct rod choice depends on the engine platform, rpm range, boost pressure, piston weight, stroke and intended use.
Why does Spool not list one horsepower rating for every conrod?
Horsepower alone does not determine conrod load. Rod stress is affected by rpm, stroke, piston and pin weight, cylinder pressure, tuning quality, boost, fuel type and drivetrain shock. This is why the complete engine combination should be considered when selecting the correct conrod.
Where are Spool conrods stocked?
Spool conrods are stocked in Brisbane, Australia. Orders are shipped nationally and internationally, usually within 24 hours when the item is in stock.
Need Help Choosing the Right Spool Conrods?
If you are building a street, drag, circuit, drift or high-boost engine and are unsure which rod package is right for your combination, contact Spool Imports for application-specific advice.
You can also view real-world results from customer and workshop builds in our Project Cars section.