TOPIC: Oil ratio on Big Twin

So I'm just wondering here - everyone I ever see write about the big twin engines says to run them at 24:1 up to about 32:1

At idle/troll speed they all smoke like bloody hell and they make an oil slick at the dock. I'm redoing a 1956 and a 1957 Javelin. so I bought an original parts lists and service manuals on ebay. In looking over the diagrams, the crankshaft bearings are ball type, and the connecting rod (big & small ends) are caged needle. With that bearing compliment - shouldn't these engines be able to be run at 50:1 ? I had been told that these engines weren't ball & needle, but that clearly isn't the case - at least that I can see. Omc modified the requirements for their engines to take 50:1 in about 1964 or so.... Wouldn't that apply to earlier engines with hard bearings?

The biggest difference between your '56 & '57 and the 1964 & up models is the thermostat on later models, starting with the Fat Fifties in 1958 and phased in over a couple years on all models save for the 3hp. Your motors run under a larger range of tolerances depending on ambient and water temperatures, load, etc. Thermostatted motors run much tighter on the tolerances due to the moderation of the engine temps, hence the ability to run a leaner oil mix. That said, some folks have run their pre 1964 t-stat motors on leaner mixes without issue. Personally, I stick with the manufacturer's recommendation... most of the time. Your Big Twins, definitely stick with 24:1... You can alleviate some of the smoke and slick by experimenting with various oils. Some synthetics and synthetic blends burn cleaner with less smoke.

You can run your motor at any mix you want but if you want it to keep running for a long time stick to the 24 to 1 mix. They knew what they were doing when they bilt those motors. A little more oil is better then not enough. As said try diffent kinds of oil and see what works best for you. But smoke is part of old 2 cyl motors.
Mike aka the pirate.
I have about 40 motor in all hp and years

I didn't even think about the thermostat issue. I hear there is an oil that smells like french fries anybody know what that might be? Synthetic - bio-degradable??????

Amsoil Saber pre-mix is synthetic, smokeless, and can run up to 100:1. But it is $12 a qt.

My favorite for many years has been Pennzoil full synthetic. About $26 a gallon at Menards.