I stopped by the Comp booth at Sema this week and talked to some technical folks about Comp's lifter program. One of the guys was pretty familiar with the DLC testing program and he said the plan was for Comp to offer the DLC option on all vehicle makes for (flat tappet) lifters going forward. Pontiac is scheduled for "sometime next year" with SBF up next for the upgrade. SBC and BBC are available now. Current pricing is +$20 per set (16 lifters) to get the DLC coating.
In the pic below you can see they are coating only the lifter face, not the body of the lifter.
The fellow I spoke with said they had done extensive Spintron testing on coated lifters and could not force a failure even with abusive testing. According to him, the coating does not wear off after break in and is not sensitive to oil additives.
I asked about combining a Nitrided cam with DLC coated lifters and he said they had done no testing on this but should increase durability even more, but in his view was unneccesary as the DLC was enough.
All Comp lifters are now made in Michigan, with coating outsourced to another division of Edelbrock/Comp also in Michigan.
He said that in Spintron testing the greatest cause of premature lifter failure with uncoated lifters was excessive coil spring bind height of the spring- #1 killer.
On the roller lifter front the Evolution roller cartridge program has been very successful (according to him) and going forward all Comp roller lifters will migrate to this technology, replacing the existing roller design.
Time will tell, but it looks to me like Comp has taken the lifter failure issue seriously and put in place some good upgrades.
The main point I got from all this is that the DLC coating of inexpensive flat tappet lifters (when available for Pontiac) gives everyone that doesn't need large valve lift numbers a really good option away from the expensive roller cam setup.
