Billet cams and lifter supply

[SSDiv6]

Originally Posted by Billy Nees

Rollers DON'T add reliability, they just allow bigger, more aggressive lobes that allow higher engine speeds that will make bigger and more "manipulated" cylinder heads more of a necessity which will just drive costs higher and make engine failures more frequent. Now that right there sounds like a good way to get rid of Racers.

Billy,

The issue is that there is only one solid/hydraulic lifter manufacturer left in the USA. The only other manufacturer left in the USA, makes only hydraulic roller lifters. New engines are either hydraulic rollers or OHC. The business model for earlier engines that run a hydraulic or solid tappet style is no longer a market the bean counters want to support with USA made products.

Moreover, there is both an issue with cam core quality and lifter quality, especially when they are made overseas. Then add the EPA imposed restrictions on lubricating engine oils, it creates more issues.

As regards to camshaft design, running a roller lifter/camshaft does not always allow a performance increase since the roller wheel diameter places a limit on how aggressive the lobe can be. One example would be the Olds 307 engine, which was available with both a hydraulic tappet and roller lifter. In Stock Eliminator trim, the hydraulic tappet engine, even with solid tappet lifters, is faster than the roller engine.

Since you been around as long as I have, you may remember in the early days, there were "Mushroom" style solid lifters available to run aggressive lobe profiles because it provides a larger contact area.

If there were to be a rule change to allow the use of hydraulic or solid roller lifters, then they should limit the roller wheel size to OEM which is 0.700". This is the roller wheel size for all OEM applications.

Allowing a larger roller wheel diameter has the same effect as using a larger size tappet style lifter. With roller lifters, the diameter does not make any difference, however, the roller wheel diameter does.