Absolutely Robert. No argument with any of that. My statement is the lifter is supposed to spin when the cam lobe hits it but a new engine with new parts does not always spin the lifter on initial start up, hence the 2,000 RPM break in period of 20 minutes to get it spinning on start up and then they are good for life. We saw hundreds of failed cams and lifters calling on a couple hundred machine shops, some of these built as many as 1,500 engines per week back then, I think small block Chevys accounted for about 40% + of all the engines we saw built. Most cam failures I was involved with could be traced back to a very slow start up on the new engine so excessive cranking on the starter without a proper start. Low RPM cranking or even normal idle on a new start up can first scratch the lifter as the cam strikes it and then continue to do damage, I have seen these on tear down when there is a nice straight scratch right across the lifter foot, the scratch quickly becomes deeper and then ends up cupping out, the cam lobe hitting on the cup rounds off and becomes total cam failure. Opposite of these start up issues is when a cam with maybe 80,000 miles on it goes flat for who knows what reason, maybe a lack of hardness on manufacture or engine oil that did not meet a quality standard, I don't really know, the cam lobes are hardened deep, about 3/8" deep on the tip of the lobe is normal, or that is what was done prior to 2004 when I moved out of that department. One thing I never saw, maybe you have, the Eaton lifters that were OEM GM, had about a 1/8" thick hard plate attached as the foot of the lifter. I never saw one of those cupped out but they were more expensive so most shops used the Sealed Power style lifter with the hardened foot but no hard plate attached. The Sealed Power Design is made today by Topline, I think he markets them as Hy-Lift lifters, which was the Sealed Power Plant in Michigan. They are still building them there, or resumed building them there after that plant was closed for 3 or 4 years in the early 2000's. Based on what I saw the old Eaton design was superior but Eaton moved their manufacturing over to Roller Lifters and other companies had to fill the flat tappet void.
A new lifter in an engine needs a break in, it breaks in to the lifter bore and to the push rod, there is a little friction in each on a new start up that needs to be broken in to reduce it. Same as engine bearings and piston rings, on a new start up you have increased friction and heat but all that smooths out pretty quick as the parts get used to working together.

 

This is why I've recommended and only use GM hydraulic lifters. They still have the hardened disk and that is just one reason to use them. Our rep, like you were, back in the day told us GM would only accept pre pumped up lifters. I said what do y'all do with the ones that don't hold pump up put them in trays and sell them to us. lol because we did have a few issues with lifters that wouldn't stay pumped up. They cost a little bit more but not having to worry about pulling an intake is worth it to me every time. Too bad they don't sell solids anymore. I don't know which lifter companies are still open today and producing flat tappet lifters.


Ive mentioned this often. I built a 401 AMC for my son in laws brother. I have warned him about having it ready to crank up immediately because AMC also have an issue with the distributor gear needing oil as soon as they fire. He wiped 14 lobes off. I asked did you do the break in procedure. He said I never got it running well enough to do it the cam was soft. NOT! I had to go back through it completely new bearings and clean everything. I installed it and broke it in that time.

 

I have not seen the Eaton design lifter for many years but I have not been involved in the trade for several years now. Last I heard Eaton had stopped making them around 2002 and GM has not made them in 40 years. The patents have all expired so anyone could tool up and make them. Are you still able to buy the old Eaton design with the hard plate today? I think most of the players today are actually buying lifters from Topline Hy-Lift. Melling, Sealed Power, Manley etc.

 

I think you need to get it apart, manifold off to see what you have.

 

Like you I've been out of it a long time now. But GM still sells these, I always buy them if I'm working on a hydraulic Chevrolet.