Originally Posted By: mechjames
I'm asking this question on behalf of my friend. We're almost ready to fire up his 1950 Dodge D35 motor in his 1950 Dodge Wayfarer. It was bored .40 over and built with a 3/4 race cam. Decked, Milled, ported and polished head. Will start out with 1 carburetor, but might eventually get a dual carb intake manifold.
An estimate of horsepower might be around 125-150, but we haven't been able to dyno it yet. I believe it has the 218ci motor, but might have the 235ci.
What would be the best oil to run in this motor?
You're making me wish I had the resources to restore my '49 Plymouth (217 CI flathead). Best I can do for it at the moment is to keep it in enclosed dry storage... but SOME day...
At any rate.... if it were mine I'd plan on running something like Rotella T (conventional 15w40 or preferably synthetic 5w40) after break-in. Back when I had my '49 on the road in the 80s, I just ran garden-variety 10w30 and it liked it fine- never saw oil pressure drop below 20 PSI, never saw it over 40. Those old flatheads have a really simple oiling system, and are really easy on the oil temperature-wise. Typically Mopar flatheads didn't ustilize a full-flow oil filter, instead they sent only a portion of the oil flow through a canister filter, and counting on the "embedability" of the thick babbit layer used on bearings back in those days to deal with the occasional bigger bit of grit. Another good reason for sticking with a synthetic HDEO in my opinion.
And of course its got a flat-tappet cam (although the spring pressures are pretty mild) but that's another reason to stick with an HD engine oil.
