Engine Oil

[cbchief]

Hi All, I know it's been discussed & bandied about but I need to know the best engine oil for my 56 Square Four. I'm new to the club & will have many questions in the future about a multitude of subjects. I've been looking at the synthetic diesel, oil in 20w/50 containing zinc by Amsoil. Is it worth the money. I know the rotella in 20w/50 was used for many years but I can only find it in 15w/40. All suggestions would be helpful. Thanks, Tom

[phil.auldridge]

Tom,
First, my apology in the delay of your post.. a technical glitch in the forum which I just discovered!
Ask 10 guys about engine oil, and you will get 10 different opinions. There are so many variables: age and operational history of the engine; is there a filter?; type of oil pump?

I can only note my personal practice and opinion, formed after reading lots of other opinions:
My Square 4 MK II engine was just rebuilt earlier this year. I have the Morgo pump (highly recommended, as the gears in my original failed, likely contributing to a broken rod), and addition of a Dragonfly-provided accessory oil filter. I've opted to use 40wt non-detergent for the initial engine break-in.. the first oil change after initial 15 minute static run of the engine, and two additional changes, leading up to 1,000 miles, where I have changed over to a good quality 20-50w synthetic oil to which I will be adding a ZDDP zinc additive for good measure. Right or wrong, I feel good about this approach.
Phil Auldridge
Austin, TX