Technical Flat Tappet Cams Really Bad?

For a stock or mild street driven engine, if all the lifters are rotating does that mean that all the push rods should also be rotating? Any difference between a fresh build with new parts and a well "broken-in" engine with maybe 40,000 or 50,000 miles on it?

In other words, if you've just got the valve covers off and only some but not all of the push rods are rotating, is that automatically a cause for concern?

 

Absolutely make sure the lifters are rotating, some of these engines are on their second or third rebuild if the lifter bores are wore out problems will likely occur. Not sure on the cost of having lifter bores bored out, a larger diameter lifter is a benefit. Roller cam and lifters have benefits however they are spendy and also fail. I wonder how many lifter bores are checked for wear during a build?, is this one of the main reasons for failure? I don’t know what the causes for failure are, I don’t sweat it, check cam ,lifters, bores, rotation of lifters and use cam lube and zinc oil so far so good.
Dan

 

Look at post 25. The pic of the grey grease on the lobes but not the journals. This is the method I use as well. I use the MOLY base assembly lube/grease on the lobes, while I use the red assembly lube that came with the camshaft only on the journals. The red lube is sticky, but I have no idea how well it would cling to lobes if my build gets delayed. Additionally, the thick Moly lube really seems to be the ticket.

Many people want to break it in for 20 minutes, varying the rpm from 1000rpm or so, up to 1800-2000ish. My machinist that breaks in a lot of engines on his dyno told me he only does 10 minutes or so at first- if it's leaking a tiny bit of water or exhaust, 10 minutes wont hurt. After ten minutes, he shuts it down and addresses the leaks, etc. while the mill cools COMPLETELY to let the metal relax. Then he does the second ten minute half of the break in session.

I copied his method and it's not failed me yet.

After the cam is completely broken in, full pulls to get the timing and fuel dialed in, along with fully seating the rings.

-rick

 

I did a 4hr cool down to let all components stress relief as well.

On Fresh builds, 2x 4hr cool downs after reaching operating temps.