What solid roller lifters are you running in your LA non roller block
Everything has its limit/ceiling, resonance frequency is not something I'm worried about at the level of rpm operated at. After a ton of 6900 shifts the lifters look new. I can believe you had a failure at some point , that you were at such rpm level that the engines internal operating frequency matched your roller wheel frequency... did the body crack ?did the wheel disintegrate? So far the only talk of this phenomenon ... is coming from you. I'd like to hear more specifically as to how, what brand,rpm, app this occured. The lifter body fits a .904 hole, that makes the body a .903 body with .750 wheel. Sbc uses both .750 and .810 wheels. Fitting isnt seemingly an issue. I'm one of those guys that has always heard nightmare stories from people about not to use this or that most of the time I find out the problem was with them and set up, or use beyond the products app. When I do share a failure .. it turns out to be unrelated to their explanation/cause... not 100%...but about 99%.
It depends on the cam core. The bigger the core, the quicker you run into frequency issues. I learned it from Dan Jesel. So it happens more than you know. I sent him some Crane lifters I was killing. In fact, I called to order a set of his lifters that were a hundred bucks each back then in 1996. He wouldn't sell them to me,because he said I didn't need them. So I sent him a few of the killed piles of crap and HE made the diagnosis.
He had me write a note to Chase Knight and I sent those lifters back and Crane sent me a set of Pro Series with .810 wheels and the issue stopped.
Again, if you know anything of resonance frequency, you know a hundred factors can cause a problem. The diameter of the core, the materiel of the core, total lift, rocker ratio and even rocker materiel will affect resonance frequency among many more things.
Again, the cheap *** lifter companies should not even make a .904 lifter with a .750 wheel. There is no reason other than 95% of the lifters they sell use that little wheel and they cost most less than the bigger wheel.
Without spending a ton of time on a spintron, you never know what frequency you'll have issues with. And the consequences of resonance frequency are quick and devastating.
We started with ductile rockers. 7100 would kill the wheel. It would also take the lobe off the cam, bend the pushrod, and bust the rocker. The next switch was to aluminum rockers and that took it to about 7500. Then 7/16 straight wall pushrods got to maybe 7700. And every time it killed a lobe, rocker and pushrod. Double taper pushrods got it to 7900. Then I called Jesel because it became apparent that the lifter went first, which was exactly what everyone else said wasn't happening.
Live and learn. I've seen guys have issues at less than 7k. It all depends. Why risk it?
