Here’s an example of a part...
Here’s an example of a part that will ruin your day, and probably your engine too: a failed solid roller lifter. Run in a street application, this lifter spit its needle bearings after a few thousand street miles and lodged its body into the lifter bore. The cam lobe was toast too.
When it comes to bragging rights on the street, few speed parts have the allure of serious hardware like a solid roller cam setup. After all, when it comes to the camshafts, the solid roller is at the top of the lineup, and all of the serious racers use them. So, does that make it the correct choice for a hot street application? For years, the definitive answer was “no,” since the longevity in a street application can be compromised, and when a failure occurs the results aren’t pretty. Failure usually occurs at the lifter, with the tiny needle bearings supporting the rollers giving up, filling the engine with damaging debris.
So, with that potential for disaster, why are solid rollers seemingly more popular than ever in street engines? The same characteristics that make a solid roller setup favored in racing carries over to the street—the ability to make more power and turn higher rpm. In fact, in today’s high-performance world, the temptation to run a solid roller is greater than ever.
The Lunati lifters supply...
The Lunati lifters supply oil to the pushrods via a conventional bore-wall orifice directing oil to the pushrod seat. These small-block Chevy lifters are .300-inch tall to fit universally in early, late, and most aftermarket blocks while the pushrod seat height is kept at the standard short lifter height.
With advances in cylinder head design, modern performance engines make more and more power as the valve lift is increased. Add air-hungry big-inch stroker combinations and bulletproof bottom end parts capable of serious engine speed, and it becomes pretty hard to leave the available power potential on the table. To take advantage of the high-lift flow of modern cylinder heads, you need to actually open the valve deep enough to tap into the flow capacity of the head. This drives lift to a much higher range than what was common on the engines of yesterday. Coping with that high lift, and aggressive, fast-acting lobe designs, as well as the rpm requirements, points to the load-handling capabilities of a solid roller.
Typically, a flat-tappet design is going to be limited in its ability to handle the high valvespring loads demanded of very high lift and rpm, while maintaining valvetrain control. Another option is a hydraulic roller, but for serious high-rpm, big-power applications, these too have definite limitations, especially in rpm capabilities. That leaves the solid roller as the lone option, along with its attendant longevity shortcomings. For many, it is well worth the risk for the power gained. To hedge your bet here, a set of premium roller lifters serves as an insurance policy. Solid roller lifters are definitely not an item you’d want to cut corners on.
Lunati’s Pressurized Solid...
Lunati’s Pressurized Solid Roller Lifters enhance durability with full-pressure oiling to the needle bearings, and have material and manufacturing standards that are among the highest anywhere.
We had a chance to review some of the premium solid roller lifters from COMP, Lunati, and Isky, and although each has their unique features, the common theme is to improve durability in any application. Much of the effort comes down to premium materials, as well as improved oiling. If a solid roller is going to be your choice for a street-bound muscle motor, one of these lifters will greatly improve the odds of survival. None of the manufacturers we spoke to implied that an aggressive solid roller would provide OEM durability in a daily driver street application, however, with routine maintenance and inspection, and premium lifters, a solid roller will get the most out of your street bruiser.
Lunati Pressurized Solid Roller Lifters
To direct full-time pressurized...
To direct full-time pressurized lube to the bearings, these Lunati lifters (PN 72443) feed from the oil gallery reliefs with a drilling aimed straight down to the bearings.
Lunati’s top-of-the-line solid roller lifters are built with premium materials, including a polished tool steel body, with tool steel axle and wheels. The machining tolerances, rigorous quality control inspection, and heat-treat specifications all add up to a high-quality part. The step up in terms of longevity comes via pressure-fed oiling via a drilling straight from the oil gallery relief, down to the roller wheel and bearings. This ensures a continuous supply of lubricating oil where it is needed most.
Isky’s EZ-Roll is an optional...
Isky’s EZ-Roll is an optional bearing arrangement employed on their successful Red Zone solid roller bodies. The design was originally produced for extreme drag race spring loads, but the durability has proven an asset in a variety of applications.
As Lunati’s Shane Pochon tells us: “Going to a solid roller in a street application, the biggest thing is the bearings on the wheel and axle. It’s important to keep oil on that, so that is where the pressurized oil is beneficial. The solid roller stuff is designed for high rpm for a short amount of time and drag racing. In a street application, guys will believe the engine is staying at low rpm and is just idling around, so that will be easy on it. In truth, at low rpm the crank is not slinging much oil up to the lifters, so there isn’t any oil up into the wheel and into the bearing. The result, especially with high spring pressure and aggressive lobe design, is you end up killing the bearing on the lifter, causing a failure. If you are doing a street solid roller, what I like recommending is actually getting a street roller lobe design that requires less valvespring pressure, put a good lifter on it, and you shouldn’t have any issues.”
This cutaway lifter illustrates...
This cutaway lifter illustrates Isky’s unique “Solid Bearing Raceway.” Essentially a busting produced from a proprietary material, the greater bearing contact area is said to offer greatly enhanced load bearing capacity. The Isky design eliminates the potential for needle bearing failure by eliminating the needle bearings entirely.
Shane also suggested that regular maintenance could help avoid problems: “As far as maintenance, I recommend watching the lash. Over time, the valvetrain will settle and the lash will not vary much. If you notice the lash on one or more lifters starts loosening up more than normal, that’s when I would recommend pulling them out and inspecting them. If you notice play or roughness when working the bearing, send them in for rebuilding.”
Isky’s premium entry in the solid roller range is their unique EZ roll arrangement. The simple logic here is that if the needle rollers are prone to failure, why not just eliminate them. That was just the approach taken by Isky, substituting their “solid bearing raceway” for the conventional needle bearings. The design actually uses a full-contact bushing of a proprietary material to support the roller wheel. This arrangement actually increases the surface area supporting the bearing loads, and Isky claims the arrangement offers a 350 percent improvement in load capacity. The EZ Roll was initially designed for extreme drag racing application, with spring loads of well over 1,000 pounds, open.
Lubrication to the Isky roller...
Lubrication to the Isky roller wheel area is provided by two oil holes adjacent to the axle. The bearing material is designed to retain lubricating oil for enhanced longevity.
Rod at Isky explains that although these lifters were designed for ultra-demanding drag racing applications, the durability soon showed significant advantages in other applications. As Rod tells us: “They started out in very high load drag applications, but then the idea caught on for endurance racing, boat, and even street applications. The key factor here was extended durability and eliminating the potential for destructive needle bearing failure. You don’t break the outer shell. It’s not like a needle bearing where they shatter and break, and the failure escalated quickly. If there is wear occurring, the lash will simply open up progressively, and you’ll have more than enough time to catch it. It won’t just break on you, and that is the main thing.” Rod tells us that reports from the field show exceptional durability with customers using these lifters in very aggressive street application.
COMP’s entry into the realm...
COMP’s entry into the realm of super-premium solid roller lifers is the Race Elite. Material, manufacturing processes, and design all add up to an improved lifter. These lifters supply full pressure oiling to the bearings via a drilling in the oil gallery relief, ensuring a constant pressurized oil supply, even at low rpm.
The EZ Roll lifter bearing arrangement is an extra-cost option on Isky’s proven Red Zone lifter bodies. Oiling is provided by two holes adjacent to the roller axles, however Rod tells us the bushing material is actually a self-lubricating material, and it will absorb and hold oil. For a street solid roller, we definitely consider the Isky EZ Roll worth a close look.
COMP’s approach to an ultrahigh-end solid roller lifer is to go all-out in material and design to produce a superior lifter. Top quality starts with materials, including an 8620 steel alloy body, SAE 9310 roller wheels, and 52100 bearing steel for the needle rollers. The machining and finishing of these components are done to top industrial standards for accuracy and longevity.
An oversized axle increases...
An oversized axle increases the bearing surface area on the Race Elite, and allows for a greater number of bearings for more load capacity. The axle is pinned to the body, allowing improved channeling of the pressure fed oil into and out of the bearings.
Materials and manufacturing processes upped the ante on the Race Elite, but design features are what set these lifters apart. The oversized .400-inch diameter tool steel axle increases the load bearing capabilities, and allows for a greater number of needle bearings. The axles are dual-pinned to the body, and pressure fed oil directly to the bearings via a drilling from the oil gallery relief. The pushrod seat arrangement is interchangeable, allowing centered or offset locations, while the top end oiling is fed directly from the pressurized gallery relief, metered by the pushrod insert.
Although the Race Elite is primarily intended as a serious race lifter, the very features that make it a standout piece in that application also lend it to enhanced durability in a serious street engine.
The Race Elite lifers feature...
The Race Elite lifers feature interchangeable pushrod seats, allowing offset or centered configurations. Oil flow to the pushrod is via a direct drilling to the oil gallery relief, and metered by the orifice diameter in the pushrod seat.