The Stovebolt Site Forums The Shop Area Engine Shop New to Stovebolts: oil question

Hello all, nice forum you have here.

I just picked up a 30 Chevy Universal AD Sedan, with a 194" engine. It was rebuilt many years ago, and runs very smoothly. As with any new vehicle purchase, I'd like to change the oil in it especially since it seems a tad on the dark side to me. I read to use 30 weight, possibly 10w-30, and still others recommend Rotella 15w-40. So I'm wondering, is it just a preference thing at this point? I'm not opposed to using synthetic either.

Also, how man quarts of oil should be purchased for these engines?

Thanks

Compared to a modern engine, that one's going to have oil clearances you could throw your hat through, most likely. I'd stick with a good quality 30 weight detergent oil, and change it often enough to keep any sludge from forming since it probably doesn't have an oil filter. a 6-month interval on oil changes, regardless of mileage will prevent any condensation or other nasty stuff from accumulating. Also be sure to run it for a long enough time on a regular basis to come to full operating temperature. Short runs that don get the coolant hot tend to form lots of condensation and sludge.
Jerry

Welcome to the gang Ray!!
Jerry gives good advice.

Don

Car questions again?👎🏻 BTW, the question right below yours is about a car also, but Tiny is a very smart man and kept it generic. We’ll answer your engine questions, just don’t mention it is in a car.

Thank you for the words of wisdom, I appreciate it! I will never mention the motor is in a car again, well, unless I forget....lol....thanks!

I note that the most available oil here in the U.K. specifically stated for use in vintage vehicles is 20w/50. I have to admit I don’t really understand the numbering I think it’s viscosity at high and low temperature. Perhaps someone could educate me. Will this be ok for my 216 engine. I keep reading about needing to add zinc when using modern oils. I assume that a vintage oil has this but again not sure.

https://www.halfords.com/motoring/engine-oils-fluids/engine-oil/halfords-classic-oil-20w50-5l

Thanks

chris

My experience with synthetic it having smaller molecules it can leak past the rear main seal easier.

A multi-viscosity rated oil simply means it flows like the lower rating when cold, and lubricates like the higher rating when hot. Here's where things get a little complicated- - - -the oil does not change physical thickness as it heats up, so if someone is running a 10W-30, for instance, the oil stays the thickness of a 10 weight all the time. That's not enough "cushion" between moving parts in an engine with fairly large oil clearances. Parts get a running start and hammer each other into oblivion. I like to use at least 15W-40 oil, and straight 20 or 30 weight is better unless the engine has been rebuilt to very close tolerances. The "W", by the way, does not represent "weight"- - - -it stands for "winter", denoting the temperature at which the cold flow rate is tested.
Jerry

Good information many thanks

Welcome to the Stovebolt forum from Fort Erie, ON!

My Motor manual only go back to 1935 but it should give you some idea of what oil you require. The 1935 crankcase capacity is 5 quarts and the normal oil pressure is 12 psi @ 50 mph. I recommend getting correct owner's and factory service manual for the car. The following viscosities were recommended for 1935:

Above +32°F - SAE 20
Above +10°F - SAE 20W
Above -10°F - SAE 10W

See YouTube: Motor Oil: "Riding the Film" 1937 Chevrolet Engine Lubrication 11min

Since engine oils back then were non-detergent, any modern oil would be a vast improvement. You should be able to use any modern 20-grade oil (0W-20, 5W-20, 10W-20). By definition, all 20-grade oils have the same viscosity range (ie, 6.9 to <9.3 cSt) once warm (ie, 100°C/212°F). All oils become thinner with increasing temperature but multigrades do not thin-out as quickly as monogrades. 0W grades generally require synthetic oils.

For extra antiwear protection and far better engine cleanliness, I would also suggest a 30-grade heavy duty engine oil (0W-30, 5W-30, 10W-30, 15W-30), preferably with a dual certification (ie, API CK-4/SN). I like Petro Canada Duron SHP 10W-30 but Rotella T4 10W-30 and Chevron Delo 400 SDE 10W-30 would also be good choices.

I would not go with a 40 or 50 grade oil (eg, 15W-40 or 20W-50) because these engines had splash lubrication and were specified with a 20-grade maximum viscosity. Excessive viscosity will cause more oil to relieve back to the sump so less reaches the bearings. See Corvaiir Oil Guide and Engine Wear.

While "W" in a grade does stand for "winter", the number associated with the modern "W" in the grade does not denote the temperature at which the cold flow rate is tested. The W-grades are based on maximum viscosity specifications at various temperatures using ASTM D3244 and ASTM D5293 test methods. See SAE Viscosity Grades for Engine Oils.

Your engine may contain a large amount of sludge. Heavy duty oils can help remove this sludge because the detergents slowly lift sludge from engine surfaces and the dispersants keep them suspended in the oil. The Corvair Oil Guide has the following recommendation:

Bottom Line Recommendation #10:
Forget the myth that you can’t put high detergent oils in older engines or engines that have been using poor quality oil. I do it every day! 50% of this market is API SF or lower, frequently without thermostats. They are full of sludge. Some drain plugs come out looking like a cork, with an inch or so of thick sludge on the end. No matter what the engine, I put in a 10W-30 high detergent CI-4 oil and instruct the customer to come back when it thickens up, or the following week if he doesn’t want to check it himself. Once it no longer thickens up quickly we move on to 15W-40 and add a 1200 mile engine cleaner. At the end of that cycle we move to whatever oil the engine should have.

Thanks for those interesting links fraso.

I have learned some more stuff today