Re: 359 Straight Eight Engine

Posted by JWL On 2010/12/28 11:09:42

From what I understand, there is no need for going to a zinc additive unless you have a new camshaft, or a reground one, and/or new or refaced tappets/lifters. Modern oils have enough zinc to provide provide lubrication to these parts. A seasoned engine will tolerate the new formulated oils just fine.

But, having just said this, I use 15W-40 Classic Car Motor Oil in my Packards. This is a motor oil that is formulated for engines of our Packards' age and for those that do not use a catalytic converter. It is sold by a region of the CCCA in case lots. It may be overkill, but it makes me feel good.

(o{I}o)

Edit: I believe, that those with the old style straight-8s with roller cam followers should have no concerns about the new motor oils.