The Stovebolt Site Forums The Shop Area Engine Shop Non detergent vs detergent 30 wt oil

Trying to decide if 30 wt non detergent oil or regular oil is better for a 1950 216 motor in a 50 3100. Engine as far as I can tell is original, odometer hasn't worked in years so I'm imagining it has well over 100k miles if not more.
Any one have any advice on what to use, don't won't to add something that'll will screw it up.
Previous owner used regular 30 wt oil.

Well, to each his/her own but I like Valvoline VR-1 30 weight. Oil is about like toothpaste or toilet paper, though. Ask 50 different people and you might get 50 different suggestions.

I wouldn’t use the non-detergent.

Video link

Non detergent oil is great- - - - -for soaking a rub rope out in the barn yard. Keeps the flies off the cows.
Jerry

Agree. You don't want clean cows.

Stole it because it was easy to copy and past but i agree with these thoughts.

Sounds like your engine has not been redone as in machine shop redone and is original. And you plan is to keep it that way.

"In my opinion, you can but you shouldn’t. If you have an engine that has been running on a non-detergent oil for years it could actually damage your engine to switch to a detergent oil. You see, after so many years your engine is going to have sludge and contaminants built up within it. By switching to a detergent oil it could cause the sludge to break apart and be released throughout your engine. This could ruin several things from rods, cam shafts, bearings or anything in-between. The movement of the sludge overtime can clog your engine lines and cause serious wear on the engine. If you have an engine that runs healthy with a non-detergent, the best thing to do is keep the oil consistent.

It is important to break down the misconception that all non-detergent oils are bad. Non-detergent and detergent oils both have their benefits and downfalls but each application is unique. It’s all about making the right choice for your engine based on what it needs."

so if you need is just keep it running then go with what has been used for years.
If you machine shop that thing to new and replace all the hoses, lines etc then well you can go either way.

Just my opinion, but using non-detergent oil just continues building up the sludge and contaminants in the engine. If you're afraid of that stuff breaking loose, then do a short oil change interval with detergent oil and then continue with modern detergent oil. That and it's harder to find non-detergent oil these days.

I think the "no non-detergent oil in old engines" story got started about the time detergent oils were introduced and has lived on in infamy for 75 or more years.

Engines run only on non-detergent oil had a significant buildup of carbon and other impurities coating all the engine parts. When detergent oil was put into one of these engines -- that often didn't have an oil filter-- the carbon and sludge would get pumped through the bearings as particles big enough to hurt the bearings as the detergent desolved it.

All that said, I have taken apart engines that were run on detergent oil but without regular oil and filter changes and they can be are quite dirty inside. A good solution is a fine-micron bypass filter such as a hydraulic oil filter off a tractor or excavator. That will clean it up over time. The replacement cartridges for the optional bypass filters used on stovebolt engines are nowhere near fine enough to be effective bypass filters. They once were but the filter companies changed the filter medium in the last few years to they are the same as full-flow filters these days. At least the ones I've researched are (Wix, Fram, Purolator).