NAPA Castrol Edge

NAPA sells this synthetic Castrol 10W-60 engine oil for $6.90 quart. On a 455 Olds, running in the summer, the oil temps get hot, especially coming off the highway. The 455's are notorious for lower oil pressure readings when highway cruising.

Anyone run this engine oil?

 

I'm curious. What is your oil temp?

 

What does this mean in layman terms?

Kinematic Viscosity @ 100 C/212 F, mm2/s, ASTM D445 = 22.7 (Castrol 10W-60)
Kinematic Viscosity @ 100 C/212 F, mm2/s, ASTM D445 = 18.0 (Mobil1 15W-50)

Does the higher number indicate that the oil is "thicker" or have a higher viscosity at 212F?

 

Depends on how long on highway and how hot it is outside. If its 95F outside and running on highway for 15 minutes+. Oil temps can easily approach 210F-220F. Cruising around town in stop/go, oil temps are around 180F

 

These cars ran fine with 10/20w40 in extreme temps, nowhere has any owners manual ever recommended a 60w. I think a 20w50 would the max anyone should go in these engines.

 

I am not sure about "fine" as most stock 455's had a short lived life back in the 70's The Olds 350 was a reliable long running engine but the Olds 455 with it's long stroke, large main bearing surfaces, 2-Bolt mains, heavy crank/rods/pistons, flimsy rods, didn't make for good longevity. Spun rod and main bearings were much more common on the 455 than the 350. The modern aftermarket has definitely helped the 455 in longevity with lighter and stronger bottom end parts.

Modern high HP LS engines have 4 or 6 bolt splayed main caps and lighter/stronger components. Hence they can run tighter clearances as the bottom ends don't flex like an Olds 455 bottom end does. Bill Trovato speaks about this in his Olds engine book.

With that being said, if one just put-puts around town, never going WOT or racing the engine, then you don't really stress the engine components or get the oil temps really hot.

 

10W60??? I never heard of it. Must be something new.

 

You must be watching too much Motortrend. There's plenty of trash talking on their shows about the how bad the 455 is. I think they're just too obsessed with LS engines.

 

Olds experts and my personal experience is where I get my info from. It's not "trash talking" but simply being realistic on what the 455's was in stock form and what it takes to make them handle high HP when rebuilding them. Olds engineers admitted that Chevy got the better quality engine parts for their big blocks than Olds did. A 2-Bolt main with a cast crank on a 455 is not an engineering marvel but a manufacturing oversight & budgetary saving decision for GM.

A stock LS3 bottom end can handle 700HP without issues. Good luck doing that on a stock Olds 455. Put a shovel in your trunk because you will be shoveling engine parts off the roadway.

Getting back to the OP. When rebuilding an Olds 455, looser main clearances are called for (Bill Trovato) to compensate for the flexing going on at the bottom end. Running factory 0.0015 - 0.0025 main bearing clearances on a 455 is a recipe for failure. Bill calls for 0.0030 - 0.0035 on mains. That will keep the main bearings alive but oil pressure will drop off when hot.

 

I would say that is just about perfect anyway. Much cooler than 220 and you are not burning out any condensation. I dont see where you actually have a problem.

 

Bill's right, oil temperature needs to be in that range to allow condensation to boil off. (Burning one gallon of gas produces one gallon of water, so any blowby carries a lot of water into the oil.)

And synthetic oil is not at danger of self-destruction until it nears 300°.

Do you currently have low oil pressure at cruise or idle? If so, you should restore correct bearing clearances. Extreme heavy weight oil would give you false security; it reduces flow to the bearings while consuming extra horsepower and giving you a comforting number on your oil pressure gauge. And flow is needed to carry heat away from the bearings.

At the margin, 0W-40 matches what the factory recommended for both cold and hot ambient. If your bearing clearances are at factory spec, you wouldn't need anything thicker.

Don't be wary of a low first number. 0W has viscosity of about 300 at 50° so it will flow well and still be thick enough to give good protection.

Yes, higher kinematic viscosity means the oil is thicker.

 

Kinematic Viscosity is a measure of a liquids ability to flow under the influence of gravity. The higher Kinematic Viscosity of the Castrol means it will have a lower flow rate than the Mobil 1 it is compared to. You could look at it as being "thicker". This is what you would expect from a 60 weight oil vs. a 50 weight oil under the same temperature conditions. I do not know the complete specs on the Castrol, but I do know the specs on the Mobil 1 15w50. The Mobil 1 is specifically engineered for flat tappet cam applications, and high temperature/high stress conditions. It is also full synthetic, with 1300ppm of Zinc and 1200ppm of Phosphorus for added protection in flat tappet cam applications. The Mobil 1 is what I run in my '67 4-4-2 with a "built" 400ci. Here in St. Louis where the summer temps regularly reach 95° or above, my car seems to love it. Just my 2-cents.

 

Kinematic viscosity is not viscosity.

 

"Kinematic viscosity is a measure of a fluid's internal resistance to flow under gravitational forces. It is determined by measuring the time in seconds, required for a fixed volume of fluid to flow a known distance by gravity through a capillary within a calibrated viscometer at a closely controlled temperature."

https://www.machinerylubrication.com › ...

 

Sorry, should have explained that better. Kinematic viscosity is (dynamic) viscosity divided by density. That definition is a little clunky. Simply, kinematic viscosity is how fast you go per specific force, and dynamic viscosity is how much force you need for a given flow. Being engine dudes here, we should be interested in the latter.

 

This video is a nice clear explanation:


I was on the Corvette Forum and found out the C8 engine using 0w-40 is around 18psi when at hot idle. Even more surprising. When at 6,000 RPM +, and hot, the oil pressure never goes above 46psi according to the ECM data tables people are posting online. With that being said, the GM factory & GM engineers actually recommend 15w-50 synthetic for the new C8, if you are tracking/racing it. The 0w-40 is standard fill for all new C8's.

Per the GM owners manual for a C8:
"0W-40 dexos2 engine oil is approved for both track and street use. 15W-50 full synthetic engine oil may also be used for track use, but after track use must be changed back to 0W-40 dexos2 for street use."

So on a 455 Olds that sees street use with sustained upper RPM use (not a 1/4 mile drag car that just starts, does a burn out, does a 1/4 mile run, shuts down) will see much higher oil temps. Especially with .0035 main bearing clearances, the oil pressure will drop under those conditions. 15w-50 is standard fill for such 455's and even 10W-60 would also be acceptable for those really pushing the 455 hard on hot days with sustained highway RPMs.

 

Modern engines are designed to use far lower viscosity oils and lower oil pressures to reduce internal friction losses. The engine design, materials, bearing clearances, etc are all selected for that. You can't compare a 50 year old engine design to a new one. Having said that, I think 60 weight oil belongs in the rear axle, not the crankcase.

 

10W-60 is standard factory fill for all new M3 BMW's and also Mercedes Benz, along with other new car manufacturers that see high performance driving. The new Corvette C8 recommends 15W-50 if tracking the car and some people run it on the street when driving hard and fast.

 

Larger clearances REDUCE oil temps, not increase them. I monitor oil temps on my Dyno so when I fire up someone else’s build I can almost immediately get a good idea of their bearing clearances without them telling me anything prior to.
Synthetics typically come into their own at higher temps, not so much with conventional oils.
And as Joe said, you’re comparing modern, cleaner running, more rigid engines that run at much higher temps to ones that don’t. Apples and oranges.

 

FWIW, I put Rotella T4 15W-40 in my 96 and 71. Not because it's more viscous, but because I buy it in bulk for my 86 F250 with a diesel engine. Plus it's well rated with plenty of zinc and detergents.

I would recommend to anyone doing an oil change in a modern car to use the factory recommended oil. As Joe said, most modern engines use a low viscosity oil now (cam phasers and VVT). If I put 60 weight oil in my 2.7l EcoBoost in my 2020 F150 it'd be short lived. There's no reason to put it in my Oldsmobile.

 

Not anymore. Pretty much every flat tappet cam manufacturer now recommends NOT using diesel oils. Too much detergent.

 

Interesting. I hadn't heard that. I doubt I will change to the high-priced Valvoline synthetic oil or Royal Purple. Looks like I might go bad to the auto parts store conventional oil special.

 

Yeah more detergent in diesel oil and lower ZDDP than a few years back. It is to save particulate filters like Catalytic Converters in modern gas engines. Unlike modern gas engines, new diesels get horrid fuel economy compared to the old diesels and have emissions failures constantly. Also the Detroit POS diesels we run in our Freightliner fuel trucks run 10W30 conventional diesel oil year round and we charge it every 500 hours No mechanical issues with hundreds of thousands of kms and 10,000 hours. Now DEF issues and even a serpentine belt that would stay on the truck are a different story. What a difference in Winter starting with 10W30 vs 15W40. We are selling more and more 10W30 all the time, more and more manufacturers must be making the switch. I had know idea any manufacturers used a factory 10W60 in cars. It does look like Dodge will be using 0W40 in it's new inline 6. All the newer vehicles we run are 5W20 factory, I run full synthetic, which is handy not keep a bunch of different oil around. I do run 0W20 in the Winter, anything to help -40 starts and cold oil flow. My new Olds 358 build is getting 5 or 10W30, full synthetic once broke in. Unless your motor is worn out or cat can lay between the crank and bearings, do you need 60W oil? The high ZDDP 15W50 Mobil 1 sounds like a better choice for a 455 with big clearances.