Originally Posted By: 1999nick
Originally Posted By: ARCOgraphite
you have to know what the bearig materials are, detergent oils can kill certain bearing materials.
No problem with detergent oil in a 1954 Ford V-8. The detergent oils had been out for years at that time. That was the first year of the overhead valve v-8 in Fords. My Dad got me one when I graduated from high school in 1954, and by 1959 I had 140,000 miles on it, and it still ran good, did not smoke or burn oil in a 2 0r 3 thousand mile OCI, and had never required a valve adjustment on its mechanical valve lifters.
This mileage was all on Sinclair straight 20weight oil, winter and summer. 80% of those miles were highway miles.
Nick: I'm with you on the viscosity thing. If you look at the original literature, you will likely see a 30 grade recommended for the summer season. That recommendation is still valid, I think. Obviously a modern multigrade with that 30 grade 100c viscosity will serve and eliminate the change to a winter grade 10 or 20.
As to ZDDP, well, in '54 it wasn't a universal additive. I wonder if it was even factored into the OE recommendations. Still, it's nice to have and I would certainly want an SL level of the stuff... which does come in a HDEO. If it was me, I'd run a 10W30 but I suppose for a collector car a 15W40 will do. Certainly easier to find.