For my old Toyota pickup, with the 22RE 4 banger/shaker engine, it seems like a lot of guys are obsessed with the ZDDP content of the oil, and even go as far as to run diesel engine oil for higher ZDDP levels because they believe their cams are going to melt away without it. I think stock, these engines have a valve spring pressure of under 70 lbs. Our local auto shop is one of the best in the state, and the owner knows more about all makes and models than anyone I have ever met before. In his experience, these engines almost always die on the bottom end, and hardly ever anything serious with the top end. He used to race this exact engine and had plenty of additional experience destroying them, on top of just seeing what came through their shop.
Even if the cams are not made in the most robust fashion for hardening, etc... would an engine with 70 lbs of spring pressure and non-aggressive cams need any sort of ZDDP levels over 800 ppm? Is there any sort of rough chart that gives an idea of how spring pressure could correlate to needed ZDDP levels? Of course many factors would need different charts, but I could imagine some sort of baseline could be displayed, right?
I'm using Mobil 1 10-40 HM in it now, which has a ZDDP ppm of 900. Even with an engine that does not have great design in the cam hardness and toughness, would this level of ZDDP be more than adequate for my engine?
Even if the cams are not made in the most robust fashion for hardening, etc... would an engine with 70 lbs of spring pressure and non-aggressive cams need any sort of ZDDP levels over 800 ppm? Is there any sort of rough chart that gives an idea of how spring pressure could correlate to needed ZDDP levels? Of course many factors would need different charts, but I could imagine some sort of baseline could be displayed, right?
I'm using Mobil 1 10-40 HM in it now, which has a ZDDP ppm of 900. Even with an engine that does not have great design in the cam hardness and toughness, would this level of ZDDP be more than adequate for my engine?
