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What weight oil should I use in a 1941 216 engine. Manual says 20w. I was thinking 30w or 5w30. All advice appreciated.

In your part of the country the 30 would be what I would put in.

I use 10w30 without problem. Oil is much better then when those standard were written. 10w30 will work year around.

Oh SNAP! You didn't... LOL

15W-40 or 10W-40

Oil is not only vastly different than the 30s-80s but even the way they test the oil is completely different.

Its all about CAFE standards. Car companies would run Unicorn pee if it met/beat the CAFE standards.

In FL I would use a multigrade 40 weight. You are not concerned about cold weather starting... but ambient temps for summer. 10W-40 would cover everything that would see.

The oil in a 216 needs to be thin enough to form a mist to lube the cylinder walls, I would caution against using the 15-40 or 10-40.

I recently went from 10w30 to 15w40 and have seen some improvements in several engine area's.
I haven't been into the bottom end yet but the head has been totally rebuilt with the exception of the rockers and push rods.
Improvements I've seen w/the thicker oil:
1) Higher oil pressure. With the 10w30 the oil never got to 15 psi. I would gestimate 12 to 13 psi max.
With the 15w40 the oil idles @ 15 psi and I'll estimate 17 to 18 psi @ speed.

2) The engine it quieter. Theres less valve train noise and no bottom end noise.

Neither oil produced any smoke and engine temps were about the same.

I'll be closely monitoring the engine come colder temps as this will the my 1st winter w/the truck running. I'm not adverse to changeing to a thinner winter oil if necessary.
For warm/hot weather temps the engine seems to run much better w/the thicker oil.
Dave

thicker oil cause higher pressure and less flow thus less lubrication

i will use 30w

No question about a bit higher pressure with thicker oil, it doesn't take much pressure for a 216 to last a long time. The bigger concern is the oiling of the cylinder walls.

Most motors have squirt holes on the con rods to lube/cool the piston. My L134 and 270 have them... its not a magical 'mist'.. its a squirt of oil.

Next time you have a con rod in your hand look at the squirt hole... most likely its semi blocked by casting flash or when they ground off the casting flash a bur.

Thinner oils don't lubricate 'better' than heavier oil (although some properties of heavier oils give it an advantage). They may flow a little slower, but your oil pump is a fixed displacement pump... every turn puts out the same amount of oil... your pump doesn't care TO MUCH about the viscosity... its going to move it (IIRC a mid 50s 235 oil pump makes rated flow of approx 4 GPM at 1100-1300 RPM)

Not to be argumentative but a Chevrolet 216 does require the oil to be misted to properly lubricate the engine. Using thicker oil in a 216 really does more harm than good.

Every car (just about) requires an oil squirt hole. Calling it a mist is semantics. Look at your con rod.. the squirt hole is a simple drilled passage.

I think I can even find you the drill size they used, if you like.

I'm not talking about the connecting rod splash system... just the squirt hole. Its just that.. a drilled hole.

Mist or squirt.... same thing.

And the viscosity difference of oil at temp (100C for motors) is negligible. The real issue is COLD oil starting.

That's where synthetic oils kick butt.

Understanding low pressure oiling. Takes a minute or two to get to the nitty gritty. 8:30 into the video will answer the question.

Its very similar to Steve Martin in The Jerk when he is in the swimming pool and makes a fist and squeezes and unsqueezes. Pretty much explains it all!

So you are actually gonna argue 'mist' vs 'squirt' even though they are interchangeable and have no significant difference in this application?

WOW... people really have their pet peeves.

Google 'squirt hole' at your own risk

That video was neat.. I enjoyed the 12ft wood ski's and the folks in the log flume dressed in suits and dresses. That was HILARIOUS.

If you want to argue terminology start another topic, the question was asked about what weight oil to use. There have been a few responses, and along with them some the information was provided to back up the answer. Technology and engineering have changed since the 216 was designed but the learned practices have held true for 75 plus years.

FYI on modern multigrade oils. The modern 15w40 oil actually has a thinner viscosity when cold than the factory recommended straight 20w! This ensures much better oil flow when the engine is cold hense better startup protection over the old factory recommendation.

Since the bottom end of my 216 has atleast 99k miles on it, probably more since the speedo is inop, those new machined tolerances have ben well worn down by now especially once the engine warms up & expands to it's normal operating temp. And as evidensed by several factors i.e. little loss of oil pressure, lower internal engine noise, no noticable increase of engine temps, the thicker oil is filling those increased tolerances with a slightly thicker film of protecting lubrication when warm.

I will agree that a brand new or freshly rebuilt 216 w/factory new tolerances should run a straight 20w or even better a 5w20 multigrade but in my case I ain't dealing w/brand new factory tolerances

re. 15w40 oil. this multigrade oil has quite an impressive track record of providing both new and old industrial engines proper long term lubrication. It's the standard oil for OTR diesels, heavy eqt machinery & agricultural engines and has been for decades. All ICE's require the cylinder walls to be coated w/a thin film of oil during operation and if this grade of oil didn't provide this it definitely wouldn't be the standard.

Oil can be an interesting subject. Theres too many variables so one size doesn't fit all.
Good luck
Dave

ok i put 30 weight in it. will see how it does. thanks for all the advice.

90% of all wear is at start up. The oil is cold (ie not at its rated viscosity) to thick to make a good film. using a 15W-40 means that your start oil is much (I hate to use this word) thinner (really, I mean LESS viscous) and creates a proper film much more quickly. The 15 weigh it to 'thin' to run with on a hot day, so the 40 weight protect you much higher temp wise.

I can post you links all day long if you promise to read them.. otherwise I'm not wasting my time.

60+ year old manuals have no place except for the unique systems used in early motors. Most factory manuals from the 40's say use 20 weight oil (mineral oil) with no detergents (it wasn't invented yet!) or additives. So no, the manual is not always right. Should I still use leather seals? They work, but last less than a third as long as neoprene.

If you want to use 30 weight.. it's not 'wrong'... but there is a better option... because you want to keep that babbit in the bearings as long as possible and avoid an expensive re-babbiting.

I'm probably stepping into a rattlesnake pit here. But I'd also use 30 weight in summer, 10w-30 in the winter (below 32), if your going to drive it any.
One thing with the older engines is tolerances were not as tight as on modern engines. Bearing clearances ect.... So you really don't want to get into the 0 or 5w stuff.... never figured how you can have 0w oil? As Farber says "they'd run camel pee to meet CAFE".....

John

Any oil is better than no oil.

Don't let the low winter (or more correctly, 'cold') number fool you. Oil lubricates just as well at 10 weight as it does at 40 weight.

The big thing is at start up. You WANT a low viscosity oil to establish a boundary layer as quickly as possible. That's done a lot faster with a lower viscosity oil.

There are some very good articles out there that explain multiweight oils and why a multiweight is better (and a synthetic is best) mainly due to start up and (while not technically correct) 'dry' bearings (as in not enough oil to create a sufficient oil film).

It really does get technical quickly, and its not as simple as the t.v. commercials make it out to be. But it is very interesting to read.

I completely agree that 30 weight is just as good an answer as 10W40.

I was surprised to learn that oil never 'wears out' (aka loses its lubricating ability) but its the ADDITIVES that get 'used up' and require the oil to be changed. You can filter the oil clean, but without the detergents/friction modifiers, anti-oxidizers/anti-foaming agents base oil won't last long. Its really amazing what they can get modern oil to do compared to when they ran straight mineral oil.