Re: New available motor oil
Posted by Owen_Dyneto On 2014/8/25 9:15:10
Any quality SE, SJ, SL and SM or C-rated detergent motor oil of today has ZDDP (zincdiallyldithiophosphate) or it's equivalent.
Camshafts in Packards weren't damaged by even the primitive motor oils long before ZDDP even came into being (it's essentially a product that evolved during WW II). The concern is with engines with high cam loadings and that pretty much excludes all Packard engines though having an oil with ZDDP is especially a good idea for a fresh rebuild. I wouldn't use an oil without it, but I sure wouldn't be adding extra to such an oil, in excess it can upset the balance of the other oil additives - a modest number of published articles about this including some disaster stories. Oil additive blending is a science and best not to mess with it, IMO.
The attached chart from Castrol via Skinned Knuckles in 2009.
Attach file:
(50.98 KB)
Camshafts in Packards weren't damaged by even the primitive motor oils long before ZDDP even came into being (it's essentially a product that evolved during WW II). The concern is with engines with high cam loadings and that pretty much excludes all Packard engines though having an oil with ZDDP is especially a good idea for a fresh rebuild. I wouldn't use an oil without it, but I sure wouldn't be adding extra to such an oil, in excess it can upset the balance of the other oil additives - a modest number of published articles about this including some disaster stories. Oil additive blending is a science and best not to mess with it, IMO.
The attached chart from Castrol via Skinned Knuckles in 2009.
Attach file:
(50.98 KB)
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