When cranking an engine to build oil pressure the lifters rotate very slow. There is no lube being thrown onto the cam as it slowly turns.
It’s better to get the engine up and running than to crank on it to build pressure.
I’m talking about doing this on regular start up. It should never be done. Even worse is cranking the engine to build oil pressure on start up. Both are parts killers.
Roller lifters are similar. Cranking to build oil pressure with a roller is also a parts killer.
The wheels at low speeds like cranking don’t roll but skid on the lobe as lash is taken up then they start to roll. You flat spot the needles and the lifter fails.
Slow idle speeds are almost as bad for both types of liters. Very little oil being thrown off the rods and the slow rotation of the flat lifter and the skidding of the roller at low RPM causes lifter death by a 1000 cuts.
