synthetic oil

Anybody out there running synthetic oil in their flathead v8 motors? I'm building engine for my car and haven't decided what oil to run. If not synthetic probably rotella. thanks, rob drew

 

I run rotella heavy weight oil in my flatheads.had good luck out of them.

 

Be carefull of the "new formulation" Rotella, it has the yellow banner on the bottle.
It has less phosphorus and zinc to conform to the '07 diesel regulations.

Up to you, but I would add some zddp additive.

Mobile 1 extended life has a good level to lubricate flat tappet motors.

Do a search on flat tappet oils here on the hamb.

 

What he said. Flat tappet motors need help as most modern oils will not do the trick. Lucas makes a ZDDP additive that works very nicely. Otherwise - it's Chevron 15-40 fleet oil for me. Rotella is fine for motors with tight tolerances and well broken in. But it drains off (as all synthetics do) for motors that sit a week or two at a time