Pontiac Lifter Guide - Lifter Lowdown

HPP: How many different solid roller lifters does your company presently offer for the Pontiac V-8?
BG: While some lifters may fit multiple applications, we won't force a lifter into an application just because it fits in the same hole. We offer one specifically for Pontiac-No. 859-16. It retails for around $450 per set and is available direct, or through most mail-order suppliers.

HPP: Do Comp Cams solid roller lifters require lifter-bore oiling restrictors or restricted pushrods?
BG: No, they're internally restricted and contain a 0.016-inch hole that's Electrical Discharge Machined (EDM) into the body to feed the needle bearings of the roller wheel's axle.

HPP: Can you detail the positive axle-oiling feature?
BG: Oil flow toward the wheel is in the range of 5 to 15 percent of total flow through the lifter. Our in-house testing with and without holes shows no measurable effect on overall oil pressure using a standard-style gauge.

HPP: Does that testing show extended lifter life?
BG: We have a tremendous number of bracket racers running season after season on our older (non-oiling) lifters without any issues, including engine speeds in excess of 8,000 rpm, open-load spring pressures of 900 pounds, and high-ratio rocker arms that result in 0.800-inch valve lift. You'd ultimately assume that a majority of our solid roller lifter warranty issues would come from this venue of the hobby, but we found most came from vehicles driven primarily on the street.

In street applications, the ratios are typically lower and the spring loads and operating rpm are dramatically lower, so the components should theoretically live longer. Oil thrown from the crankshaft and connecting rods at high rpm lubricates the roller portion of the lifter in race engines, but the lack of lubrication in low-rpm street engines limits life expectancy. So we changed the axle material to a special tool-steel alloy and incorporated direct-oiling provisions.

Because Comp Cams rebuilds its lifters for customers, we've been able to see how much of a real-world effect positive axle oiling has had on solid roller lifters. There's been dramatic improvement across the board. The end result is a vehicle that can be driven on the street without the owner feeling as if the solid roller lifters are living on borrowed time. And while our older (non-oiling) lifters would last for years when used in race applications, racers seem just as happy with the upgrade.

HPP: What advantages do you feel solid roller camshafts typically contain?
BG: Roller cams of any type give a tremendous advantage to performance because of how fast you can move the valve into the region where heads typically flow best. With an 0.842-inch flat-tappet lifter, like that of a Pontiac V-8, the tappet moves about 0.007 inch per cam degree without running off the edge, while a roller can move the tappet 0.009 inch per cam degree or faster. This gets the valve off the seat and to max lift quicker, providing more area and lift under the curve.

HPP: Is continual adjustment a concern?
BG: It certainly was some years back, but poly-lock adjustment nuts are much better today. We suggest checking lash with the first oil change, and if it didn't move, check it with every other oil change unless you notice increased valvetrain noise at idle.

HPP: Do you see any advantage in combining solid roller lifters with a hydraulic roller camshaft?
BG: The initial acceleration rate of a hydraulic roller camshaft lobe is typically more aggressive than that of a comparable solid roller grind. The hydraulic unit tends to get the valve off the seat quicker and into the meat of the lift where the cylinder head flows best, but, unlike a solid roller grind, the profile of the hydraulic roller lobe tends to limit maximum engine rpm.