A machined groove in the lifter's...
A machined groove in the lifter's internal plunger allows pressurized oil to pass between the lifter body and plunger at a high rate at low engine speeds. It results in less valve lift and duration, which improves idle and low-speed performance. The effects are not as great at high rpm, however, and the lifter begins operating conventionally by 3,500 rpm.
HPP: Is the "ticking" an indication of excessive valvetrain lash?
JR: By design, hydraulic lifters continually adjust to maintain zero valvetrain lash and ours are no different. Once the desired setting is found, there's rarely a need to readjust either design. The noise emitted when using Rhoads lifters is the result of the valve closing sooner when compared to a standard hydraulic. As engine speed increases, the accelerated closing rate dissipates until the point when the variable-duration lifter begins acting like a conventional unit and the noise subsides.
HPP: Does oil type or viscosity have an effect on operation?
JR: Like most companies that market camshaft-related components, we, too, suggest quality conventional or synthetic engine oil that protects against lobe and/or lifter failure. Running thick oil can affect the bleed rate of both lifter designs, and generally speaking, the higher the viscosity, the less leakage that occurs, which can lessen the overall effect our lifters have on an engine. But because so many variables are involved, we don't specifically suggest using any particular type or viscosity.
HPP: What are your suggestions when breaking in Rhoads lifters and a new camshaft, and when combining new lifters and a used camshaft?
JR: We simply suggest following the camshaft manufacturer's stated break-in and normal operating procedures when using a new cam and lifters. But there are countless instances where owners find the selected camshaft a little too wild for their taste and choose to tame it with a Rhoads. It's completely acceptable to install new lifters onto an existing camshaft and we tell owners to treat the situation like breaking in a new camshaft and suggest following the camshaft manufacturer's stated break-in procedure.
Rhoads Lifters' Super Lube...
Rhoads Lifters' Super Lube and Crower Cams' Cam Saver options incorporate similar technology. Both feature a machined groove that runs the length of the lifter's body, delivering pressurized oiling to the contact surfaces of the cam lobe and lifter face.
Rhoads Lifters
Dept. HPP
202 E. Main St.
San Manuel, AZ 85631
(520) 229-9375
www.rhoadslifters.com
Crower Cams
Crower Cams is a name synonymous with high-quality valvetrain components. In addition to its roller-lifter designs, the company also offers what many professional builders consider the best solid flat-tappet lifters on the market. We spoke with the company's David Crower to gain a better understanding of what makes its Pontiac offerings unique.
High Performance Pontiac: Does your company produce its own solid flat-tappet lifters?
David Crower: Ours start out as premium hydraulic units that we outsource and convert into solid units. They feature a high oil band to minimize leaks and maintain maximum oil pressure.
HPP: How many different solid flat-tappet lifters does your company presently offer for Pontiacs?
DC: We offer three. The first is our standard lifter (PN 66962-16), which retails for $145. The second is the standard lifter with our Cam Saver option (PN 66962X3-16), which retails for $170. And the third is our standard with the Cool Face option added (PN 66962X980-16), which starts at $220. All are available direct from Crower or through most major mail-order suppliers.
In addition to its Cam Saver...
In addition to its Cam Saver option, Crower also offers its Cool Face option, which includes a tiny hole cut into the lifter face that applies pressurized oiling directly onto the lobe and lifter surfaces.
HPP: Do your lifters require lifter-bore oiling restrictors or restricted pushrods?
DC: Our solid flat-tappets are designed to promote maximum-required oil flow to the top end to cool the valvetrain components and lubricate the valve guides. They are, however, internally restricted so there's no need for additional flow restrictors.
HPP: Can you specifically detail the Cam Saver and Cool Face options?
DC: The Cam Saver option incorporates a machined groove on the side of the lifter body that delivers about 25 percent more lubrication onto the camshaft lobe and lifter to combat excessive wear from high spring pressure. On a typical engine, that might provide as much as 15 ounces of additional oil flow per hour directly onto the components without affecting oil pressure.