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Another Oil Viscosity Discussion
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WesternRed View Drop Down
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Points: 5798 		Post Options Post Options   Thanks (0) Thanks(0)   Quote WesternRed Quote  Post ReplyReply Direct Link To This Post Posted: Nov/28/2022 at 4:27am
I seem to recall 10W-30 is the standard factory specified oil for our old engines, notwithstanding som provision for climate based variation. 

I’m in the synthetic 5W-40 camp with one hydraulic roller equipped engine and 20W-60 mineral with the other hydraulic flat tappet engine that cops way more abuse.
I've finally given up drinking for good...........now I only drink for evil.
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Points: 5122 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Rebel Machine Quote  Post ReplyReply Direct Link To This Post Posted: Nov/28/2022 at 8:39am
Originally posted by Trader Trader wrote:

That article seems to support a thinner oil with the tight AMC factory clearances (mains 1-4 are 0.001"-0.002", main 5 is 0.002"-0.003").

I've been looking at 5W30 Quaker State “Full Synthetic”. The 540 Rat oil blog says it tested best for PSI value along with enough additives to use with a flat tappet cam. You can read it here: https://540ratblog.wordpress.com/

Look for "The “WEAR PROTECTION RANKING LIST itself, begins here:" heading.

This is exactly the point and I was using that oil. When that test was done, that oil had an ACEA HTHS rating of A3/B4, then it was switched to A1/B1. Sacrifice wear protection for fuel economy and emissions. Like to see results of a retest!
You have to read the container now to determine the wear protection. The API Sx means absolutely nothing except it's newer and not necessarily better! 
Read the newest ISLAC:
The proposed ILSAC GF-6B will provide the same performance as GF-6A, but with the added aim of lower HTHS to deliver potential further fuel economy benefits.




Tried to find some info on GF-6A versus GF-6B. The GF-6B appears to be for really thin oils, 0W16 and below.

This article spells out their respective definitions:
https://360.lubrizol.com/Specifications/ILSAC/ILSAC-GF-6/ILSAC-GF-6A-and-GF-6B
GF-6B is explained here:
https://360.lubrizol.com/2016/GF-6B-Lower-Viscosity-for-Higher-Performance-and-Fuel-Economy

Hopefully the product containers will be marked with those ratings so the buyer knows what they're getting. I'm gonna fly recon at Walmart and read some labels.

*UPDATE* Found this on Amsoil's website:
Engine oils can easily be identified as ILSAC GF-6A or 6B by the API emblem on the front label of the packaging. A shield represents the GF-6B specification, while the traditional starburst indicates a GF-6A product.

Found the graphic on Quaker State's website.

-Steve-





Edited by Rebel Machine - Nov/28/2022 at 9:01am
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Points: 1991 		Post Options Post Options   Thanks (0) Thanks(0)   Quote mbwicz Quote  Post ReplyReply Direct Link To This Post Posted: Nov/28/2022 at 9:50am
Originally posted by troutwilly troutwilly wrote:

I'm gonna guess JFGI means Just Frickin Googled It.
Now, as for oils, I have no input other than I use Valvoline VR-1 20W-50 for its zinc content (not looking for another discussion on that).  I would try a lighter weight but can't find it anywhere. I will also say I've never checked my engine for bearing wear.


Amazon has 10W30 valvoline VR1, but I've never seen it in a store.  That is what I'm planning on using in mine.

Mike
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Points: 75 		Post Options Post Options   Thanks (0) Thanks(0)   Quote SixunoSix Quote  Post ReplyReply Direct Link To This Post Posted: Nov/28/2022 at 10:51am
Lucas oil makes a high zinc "hot rod" oil, comes in 10W-30 and 10W-40.
Good for those with flat tappets! I wouldn't go below 30 on an older engine, but that's just me, first number doesn't matter unless your driving in winter.


Edited by SixunoSix - Nov/28/2022 at 11:11am
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Points: 5122 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Rebel Machine Quote  Post ReplyReply Direct Link To This Post Posted: Nov/28/2022 at 1:41pm
Originally posted by mbwicz mbwicz wrote:

Originally posted by troutwilly troutwilly wrote:

I'm gonna guess JFGI means Just Frickin Googled It.
Now, as for oils, I have no input other than I use Valvoline VR-1 20W-50 for its zinc content (not looking for another discussion on that).  I would try a lighter weight but can't find it anywhere. I will also say I've never checked my engine for bearing wear.


Amazon has 10W30 valvoline VR1, but I've never seen it in a store.  That is what I'm planning on using in mine.

Mike




That's what I was running.

-Steve-
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Points: 6881 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Nov/28/2022 at 2:27pm
That's a good oil.
PO, guess would be you did a good showing at that "burn out" and sucked the pan semi dry. The air/oil mixture doesn't hold an oil film well and you just scored up your bearings.
Seen many a vehicle blow the engine/transmission/differential doing burn out's.
You are probably lucky that everything else was well built and using a good engine oil. 
A lesser oil and you would likely be looking for a new engine.
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Points: 5122 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Rebel Machine Quote  Post ReplyReply Direct Link To This Post Posted: Nov/28/2022 at 3:28pm
Originally posted by Trader Trader wrote:

That's a good oil.
PO, guess would be you did a good showing at that "burn out" and sucked the pan semi dry. The air/oil mixture doesn't hold an oil film well and you just scored up your bearings.
Seen many a vehicle blow the engine/transmission/differential doing burn out's.
You are probably lucky that everything else was well built and using a good engine oil. 
A lesser oil and you would likely be looking for a new engine.



Everything in my car is overbuilt on purpose. Coated bearings, 4-bolt mains, Molnar rods, Diamond pistons, Johnson roller lifters, 727 trans with really good parts (locally built), Quick Performance fab 9" rear with Strange Pro HD aluminum third member, Strange chromoly driveshaft, 1250 Spicer 'U' joints and billet yokes. Engine a bit under 600 HP.

Don't think a short burnout would pull enough oil to drain the pan that quickly. I took in-car video of a pass I made at Cordova this year. The video shows oil pressure was stable during the burnout, which was the same amount of time as the one when I left the car show the day after. The pressure dropped just after the starting line launch. I believe that was due to slosh in a pan that isn't made for it.

I'm still baffled by both of these engines having the exact same damage. 10W30 oil was used in both. Engine shop says it's likely crankshaft 'whip'. Whatever is causing this damage needs to be corrected. We're making a couple of changes to address it. Ensuring the right oil for a given bearing clearance is one of the things I want to learn about.

I'm tempted to take the 390 out of my Machine apart and look it over. That engine endured a gazillion passes over a 20 year period with Castol 10W30 and still holds the same oil pressure. Of course it doesn't make nearly the power of the supercharged 401.

-Steve-
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Points: 3501 		Post Options Post Options   Thanks (0) Thanks(0)   Quote scott Quote  Post ReplyReply Direct Link To This Post Posted: Nov/28/2022 at 4:08pm
"Crankshaft whip"

I'm not an engine builder, I not a high performance guy. I'm just doing some thinking, & trying to learn.

Do you have an aftermarket crankshaft damper? One of those one size fits all, we just change the center to fit a variety of engines. Could it be that a damper designed for, lets say, a small block chevy, modded by the manufacturer to work on an AMC, may not really do the job? Would that be hard on the crank & bearings? Does the engine in your Machine have an OEM or aftermarket damper?

How much has the crank been cut? If I am understanding cranks correctly, every time they are cut, you lose overlap. I would imagine less overlap equals less strength, less strength equals whip. Would an uncut crank be less susceptible to whip than one cut .030?
"Prolly" is not a word.
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Originally posted by scott scott wrote:

"Crankshaft whip"

I'm not an engine builder, I not a high performance guy. I'm just doing some thinking, & trying to learn.

Do you have an aftermarket crankshaft damper? One of those one size fits all, we just change the center to fit a variety of engines. Could it be that a damper designed for, lets say, a small block chevy, modded by the manufacturer to work on an AMC, may not really do the job? Would that be hard on the crank & bearings? Does the engine in your Machine have an OEM or aftermarket damper?

How much has the crank been cut? If I am understanding cranks correctly, every time they are cut, you lose overlap. I would imagine less overlap equals less strength, less strength equals whip. Would an uncut crank be less susceptible to whip than one cut .030?


Using an ATI damper. Crank is 0.010" under.
Machine's damper is original.

I'm not clear as to what causes the 'whip' and why it's just bearings 2 & 4.

My thinking is if the bearings are prematurely worn there is a lack of lubrication under stress. Need to figure out why that is and how to correct it.
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Points: 5122 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Rebel Machine Quote  Post ReplyReply Direct Link To This Post Posted: Nov/29/2022 at 8:17pm
Spoke with my engine builder today. He thinks the 10W30 isn't to blame for the bearing damage. He thinks it was the brief loss of lubrication that did it. Maybe the same thing was happening with the other engine. I don't have any evidence to prove or disprove that. All I can do is guard against it in the future.

The good news is the cylinders honed out okay so I don't have to buy new high dollar pistons.

-Steve-
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