[Alan Roehrich]

It's not "just" any one thing.




It is oil, few oils are formulated to make flat tappets live. Finding an additive balance is tricky at best.


We're probably very close to seeing the end of cast flat tappet cores, especially the highest quality specialty cores used in Stock.


It is the tappets themselves, at most levels, the quality of machining has declined, tooling is wearing out, and the quality of base materials can be questionable.


If you're dealing with cast core cams, and iron flat tappets, realize that your government absolutely despises foundries. They hate anything that even looks like a foundry. They typically try to force out any foundry not making OE products, and they'd like to force out those foundries if they could.


Steel for billet cam cores and for tool steel lifters is in short supply. In the current political and economic climate, it is likely to remain so. That means you're going to see availability problems, and escalating prices. Honestly, if you try to buy a custom stock diameter steel billet cam, be prepared, you may wait months.


That's the state of the industry.


Now, understand, if you were to buy a steel billet, and grind it to a stock lift rule, you're grinding all the way through the heat treat. That means you're in for a second heat treat, and another grinding process.


Further, most all of the cam companies no longer employ a lobe designer on any sort of full time basis. That means there's actually not anyone there to even design you a Stock lift rule roller lobe. You certainly do not want just anyone doing that. Many of the good lobe designers are DEAD. Harvey Crane is dead, Harold Brookshire is dead, Jere Stahl is dead. I have not seen or heard anything from Steve Huggins in 10-15 years, no idea if he's even alive. Not sure about Darrel Hawkins, either. Comp Cams let Billy Godbold go. He's on a "retainer", you can bet mostly for mega dollar customers, like NASCAR, T/F, Pro Stock, etc. That's right, the number one cam company in the world does not have a lobe designer on staff. Isky hasn't introduced a new lobe in years, and they're not likely to be interested in Stock. Lunati is owned by Comp, Harold designed their last new cam lobes. Don Walthall may still be doing new lobes at Bullet.



Off the base circle, you cannot accelerate a roller lifter as fast as you can a flat tappet. It simply doesn't work. So, remember, you're dealing in most cases with low lift. under 0.530", in many cases, under 0.400". So the roller has no lift to "catch up" on, it's literally only going to just over 0.300" of tappet lift. This will require considerable development to reestablish the correct lobe profile, and duration. It may require a complete change of opening and closing events. That means you're not going to just go buy a roller, put it in, and your cam troubles will end. You may buy 4-5 cams before getting something that really runs well, and doesn't kill some parts. Bet on those cams costing you $700.00 or more, IF you can get someone to design lobes and grind cams for you. You MIGHT get ONE regrind on your expensive core.



So, NO, a roller lifter cam WILL NOT perform the same, nor will the valvetrain dynamics be the same. There WILL be a measurable change in performance, that may significantly alter the current balance of the class. If you think that you're going to just go buy a roller cam and some roller lifters, stick it in, go racing and be competitive, you're in for an expensive and ugly surprise.


And remember, like every other "enhancement" people have lobbied for, when you let this genie out of the bottle, it's out. It's never going back in. If it sets off another RPM increase, and more valvetrain damage (not to mention other parts) because of the changes, you're out of luck.


Stock is a very small market. I don't see too many cam grinders, if any, being interested in designing entirely new lobes, or multiple series of lobes, for more than a dozen different engine families to switch them from flat tappets to rollers. Especially given the amount of money most are willing to spend, and the amount of complaining most do. The return on investment is miniscule.



Roller lifters are not the solution. The most feasible solution is to work with some people to get some lifters and tappets that are compatible, and find some oils and additives that work. There's a possibility that some coatings and some surface treatments will help resolve the issues. The other thing that will help is getting the cam, block, and lifters in the exact correct positions in order to make the lifter spin correctly, and make everything stay there. Just getting the lifter bores bushed isn't enough anymore.