Your donations help keep this valuable resource free and growing. Thank you.
|
Another Oil Viscosity Discussion |
Post Reply | Page <1234> |
Author | ||
WesternRed
AMC Addicted Joined: Aug/03/2010 Location: Australia Status: Offline Points: 5798 |
Post Options
Thanks(0)
|
|
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.
|
||
Rebel Machine
AMC Addicted Joined: Jul/03/2007 Location: Western Il Status: Offline Points: 5122 |
Post Options
Thanks(0)
|
|
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: GF-6B is explained here: 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 |
||
mbwicz
Supporter of TheAMCForum Joined: Feb/20/2019 Location: Buffalo, NY Status: Offline Points: 1991 |
Post Options
Thanks(0)
|
|
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 |
||
1970 AMX, one step forward, one step back. Both steps cost time and money.
|
||
SixunoSix
AMC Apprentice Joined: Jun/02/2020 Location: Blairmore AB Status: Offline Points: 75 |
Post Options
Thanks(0)
|
|
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 |
||
Rebel Machine
AMC Addicted Joined: Jul/03/2007 Location: Western Il Status: Offline Points: 5122 |
Post Options
Thanks(0)
|
|
That's what I was running. -Steve-
|
||
Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6881 |
Post Options
Thanks(0)
|
|
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.
|
||
Rebel Machine
AMC Addicted Joined: Jul/03/2007 Location: Western Il Status: Offline Points: 5122 |
Post Options
Thanks(0)
|
|
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- |
||
scott
AMC Addicted Joined: Jul/10/2007 Location: Wildwood Pa. Status: Offline Points: 3501 |
Post Options
Thanks(0)
|
|
"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.
|
||
Rebel Machine
AMC Addicted Joined: Jul/03/2007 Location: Western Il Status: Offline Points: 5122 |
Post Options
Thanks(0)
|
|
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. |
||
Rebel Machine
AMC Addicted Joined: Jul/03/2007 Location: Western Il Status: Offline Points: 5122 |
Post Options
Thanks(0)
|
|
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- |
||
Post Reply | Page <1234> |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |