i realize this topic has gone round and round....but i have always used a heavier than typical oil and had good luck at tear downs, i.e. low bearing wear.

a friend of mine used 5w30 and 10w30 in his race car for one season and the rod bearings are toast. i'm not sure that thin oil is what caused the problem, but its one difference between his engine and mine....and my bearings have never looked like that.

sb

Nope, I've done my research on this and I believe I'm doing the right thing. I have read all the research that says most wear occurs at startup. However, I've also read articles on the NorthStar engine in particular that says the cam follower design in this motor is the weak link. Cam followers can scuff and wear quickly when oil film breaks down under hot conditions. It gets 105-110 degrees regularly here in the summer, and I drive the car and the Blazer around town with A/C blasting, so I'll trade off a little wear at startup for protection against a LOT of wear driving around in the brutal heat where the car spends 98% of its' time, and where it needs an oil with superior film strength. Nice try though. I hear ya. Davey.

Nope. I have read all the research that says most wear occurs at startup, but I've also read the research that says the Northstar motor is very prone to cam follower wear and scuffing under hot conditions where oil film strength breaks down. It gets up to 105-110 degrees regularly during the summer here, and I would rather protect against that than against the startup wear. My car and the Blazer spend a LOT more time fighting heat and crawling around town with the A/C blasting than they do starting up. Davey

Sorry I posted twice...didn't think the first one took. Now I just look stupid. Luckily I'm used to it. Davey

i use 10w30 in the wife's Jeep when we go to kansas for pheasant hunting. its cold up there.

it gets a thicker oil in the summer is south tx.

i tried using 10w30 in Fred.(D150 w/a slant) USED oil for the first time since i've owned him. he'll get 20w50 again when i get around to changing the oil. of course he's got some miles on him, too.

sb

As stated before Diesel spec oil still has the additives, I run Rotella or Chevron Delo 400 , Back in the early 80's this is what we used for a fleet of 305 chevy's that were notorious for flat cams, all ran 100,000 miles plus out of 10 units only one flat cam at 130+. these were sales rep cars and saw much abuse. A few issues back Hot Rod did a oil article with praises for diesel spec oils. Don't know what issue but within the last six months, lots of detail,facts and figures.

If you want the diesel oil with the zinc-phosphorous anti-scull additive, you better go out and search for old stock still on the shelves.
The new diesel oils now have the same SM spec as the gas motor oil. There is still some of the older SL spec out there. Last month at a Walmart, I found 4 qts of Delo with the even older SJ rating! They were pushed to the far back, you should have seen the dust and grime they had on them from what has to be over 5 years on the shelf.

I have stock piled several gallons of SL rated Rotella and Delvac. I'm not worried when it runs out. I have a case of GM's EOS (engine oil suppliment) to add when I use Molbil1, it has plenty of anti-scuff additive in it for flat tappet cams to live.
There are some other options if you want oil with zinc-phousphorous. Most NAPA stores carry Valvoline 'not for street use' Racing Oil in both synthetic and dino. Make sure it says 'not for street use' on the label, Valvoline also has a Racing Oil without zinc for newer motors with catalytic convertors. Valvoline also has an oil additive with zinc that may be as good as GM's EOS.

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Slant Cecil

I use the eos solution too. It has worked for me for years now. I would stay away from 5-30wt for anything but cold weather in newer cars. Some newer overhead cams will have cold oiling problems in the top end even with 10-30wt conventional oils, but a ester based 10-30wt oil will flow better cold than a conventional 5-30wt and is an option there. As far as the the amsoil shearing down, if it is a real ester based synthetic it will not. I know redline is ester based, royal purple and amsoil cost enough that they should be, but I don't know. Most of the others are some other base that is modified petroleum and use multi grade additive packages like conventional oil that wear out and can shear in the bearings. Diesel oil can lead to excessive deposits in the chambers, you don't really need all the detergent it has. Fine for break in if it is what the grinder wants, but I would not use it all the time. A moderate amount of eos with every oil change, maybe a third of a bottle, should be fine with your favorite oil.

so- if the oil container has the SL and SJ in the specs list, this oil has the anti-scuff stuff? (zinc/phos)

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

You easily delete your own posts as well as edit them. there is a set of controls (buttons) on the right hand side of the title bar, right next to the "quote" button.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

I use Nulon E20. Its an oil additive that has Teflon in it. The oil I use is Penrite HPR15 (15W60). I found that it goes the distance. I use the same oil in my 99 Honda BlackBird, with the additive as well and no problems.