Yella Terra gives you access to the world's largest range of roller rockers to suit every performance demand. From the entry level street terra models to the Platinum race rockers for the most severe race applications.
Yella Terra Rockers have proven themselves over the years in use, a high quality product doing a tough job and making it look easy. Yella Terra Rockers are made in Australia to high quality design standards to meet a demanding market place.
Racers use Yella Terra Rockers because they work well and are reliable.
The product range comes in three different types:
The rocker arms used on Yella Terra and Street Terra roller rockers are infinitely stronger than standard pressed steel arms providing the best in resistance to bending and breakage under high spring pressures at high RPM's.
Pressed steel rocker arms, in high performance applications, are prone to failure, A high rate of fulcrum wear, flexing, cracking, splitting and breakage are common problems that will result in power loss or possible piston failure due to detonation of the incoming air/fuel charge. Other Yella Terra rocker components such as the trunnions, posi locks and bearings greatly enhance valve train durability in performance applications.
The traditional metal tip on standard rockers literally drags across the valve tip as the rocker opens and closes causing high side loading on the valve. This inside force leads to irregular and rapid valve, valve guide and valve seat wear in many engines. The roller tip on Yella Terra and Street Terra roller rockers eliminates this side loading action, as a result engines rev quicker and freer with a crisper exhaust note and maintain peak efficiency longer.
The use of needle roller bearings at the rocker fulcurm combined with roller tip at the valve greatly reduces horsepower robbing friction in the valve train to provide a measurable power increase over standard rocker systems.
The reduction in friction with roller rockers has additional benefits of reducing the operating temperature and foaming effect of engine oil to provide a cooler running engine.
Use of high performance hydraulic or mechanical camshafts requires some form of valve train length adjustment to achieve correct clearance and geometry. Adjustable roller rockers allow these corrections to be made quickly and easily.
Yella Terra and Street Terra "Easy Fit" shaft and pedestal designs offer the most rigid rocker system without using restraining devices such as guide plates, screw in studs and stud girdles. The result is more consistent valve lift and vastly improved valve train reliability at substantially lower cost.
Yella Terra offer the largest range of rocker types and ratio combinations to suit more engine and cylinder head types and specific performance demands.
Yella Terra aircraft quality extruded arms are the strongest made and are matched to massive ground trunnions for superior durability to other brands. Oversize needle roller bearings are used for better load distribution and other hardware features premium quality materials, carefully controlled heat treatment, precision grinding and finishes that ensure reliability, minimum friction and long life.
Designed by Yella Terra and imitated by manufactures worldwide, these ingenious shaft and pedestal designs can be fitted in around 1 hour with no head removal or machining required. The Easy Fit rockers offer superior rigidity to stud type rockers thereby eliminating the need for expensive guide plates, hardened pushrods and stud girdles. The additional cost of engine dismantling, head machining, gaskets and assembly costs involved with fitting stud type rockers can often can cost as much as the rockers themselves. These add on costs that do not apply to the Easy Fit designs make them suitable for stock replacement as well as for modified engines and are exceptionally good value for money.
Over 40 years of racing and street products Yella Terra understand what make engines go. We know the performance and rocker technology backwards and with back to back wins at Bathurst and NASCAR and AUSCAR we know the stuff works.
Proudly Australian made Yella Terra and Street Terra rockers are supported by technical advice and a full range of single units and spare parts to ensure your purchase will give exceptional service long in the future.
The Street Terra series are the entry level rockers that give you the performance benefits of the famous premium Yella Terra Roller rockers used by racers worldwide for over two decades, for a fraction of the cost.
The Street Terra feature new computer designed and tested high density aluminum alloy arms manufactured by high pressure vacuum die casting methods normally reserved for critical aircraft components. Cost savings from these superior production methods are passed directly to the customers.
Street Terra use the same quality hardware as the Yella Terra Roller Rockers . The component specifications far exceed the quality, design, size and finish of many other premium type of rockers.
Compared to other products nothing compares to the oversized Torrington needle roller bearings mated to full shafts and trunnions, each of which is precision ground for durability and minimum friction. No other product has these unique features.
Beware of imitations of our exclusive sold mount shafts and Pedestal Mounts.
Dramatically improves power for performance modified engines
They are a high strength direct replacement for failure prone standard OEM arms
True roller tips eliminate standard arm side thrust that causes Valve stem, guide and seat wear
Come in Adjustable and Non adjustable versions
Nominal Ratio from 1.5 to 1.8
Largest range in Australia for most 6 and 8 engine types
Dramatically improves cylinder head life
Smoother, cooler, quieter operation for hard revving engines
Engines have higher RPM potential and get to full rev range faster
Computer designed Hi density Aluminum arms
Superior quality heat treated Hardened and Ground shafts and trunnions with Oversize Needle Roller Bearings
Most bolt straight on in around an hour. No special skills required
Guaranteed against faulty workmanship and materials for 12 months by Yella Terra - Australia's leading performance component designers and manufacturers
Bolt on pedestal shaft type rockers require no cylinder head modifications and are supplied with all necessary hardware
All stud type of rockers supplied with locking nuts and set screws
Yella Terra has a full range of replacement parts for the Street Terra rockers.
Yella Terra Roller Rockers have proven to be so reliable and durable since 1983, with the ultimate in design and proven by official Holden racing teams such as NASCAR AUSCAR and Commodore cup to give more power and reliability than other products.
The strongest aluminium rocker arms in the world with deflection and bend tests proving their aircraft grade extruded aluminium arms superior to rival aluminium and stainless steel arms. They are the ultimate rocker arm for use in high revving street engines and most race applications.
Premium quality Yella Terra extruded alumiunum roller rockers have never let a competitor down at our high speed proving grounds (Calder Park Thunderdome), where Holden and Ford Auscars required to run our roller rockers having battled in racing at an average speed of over 200km for an estimated 100,000 laps. The rockers ran for over 170,000 km at between 5000-6500 rpm
These products are internationally sold and acclaimed and have a superior design with a super strong arms which are fully machined from heat treated certified aircraft alloy extrusion. They are fitted with hugh needle roller bearings mated to precision ground trunnions/shafts to reduce friction and increase engine power.
Friction fighting roller tips minimize valve stem and guide wear and give a smoother quieter operation, correct geometry improves efficiency by ensuring maximum camshaft lift is achieved.
A huge selection of bolt on styles - Hydraulic or Adjustable - that can be fitted in less than an hour.
Stud Mount
Bolt on Easy Fit
Pedestal and Shaft
Standard and Hi ratio
Come in Standard, Stealth and Ultra-light arms
The Platinum Race rockers are designed for the most severe race applications and have the feature of wide body arms for even greater strength and resistance to deflection. All Platinum rockers feature a heavy duty 7/16" mountings for unsurpassed rocker stability.
The Platinum rockers are available in twin shaft versions for parallel valve applications and unique single shaft designs for cant valve small block and big block engines. The range covers most popular factory and aftermarket performance heads in a choice of ratios.
Rigid Mounted 7/16"
Pedestal and Shaft
Single and Twin Shaft
Adjustable only
Solid roller cam and flat tappet applications
