Interesting.  The article makes the argument that viscosity has no relation to 'wear protection capability', and the thickness of the oil film is irrelevant.  I assume ultra low viscosity might drain out of the bearing spaces faster than the pump could replace it, or viscosity that was too high might prevent large clearances from being quickly filled (?), but I fail to see the relevance re: solid lifter/flat tappet cam lobes lubricated with crank spray? 
I was especially impressed by his attitude re: break-in oil for flat tappet engines.  His point being that the tradition of rapid ring break-in has no real value, since it also means you risk wiping a cam lobe at the same time.  He claims the long, complicated break-in procedure we have been taught is unnecessary if you use the best wear-tested oil & prime just before start-up.

6 VOLTS/POS. GRD. NW INDIANA

[quote][b]DANIEL TINDER (9/28/2016)....I fail to see the relevance re: solid lifter/flat tappet cam lobes lubricated with crank spray? 
I was especially impressed by his attitude re: break-in oil for flat tappet engines....

Never mind. I just re-read Ted's post re: lifter rotation. Higher wear break-in oil (and the need for complicated break-in procedures to protect the cam) may be dictated by the Y-Block's unique tappet design. The modern pushrod performance engines the blogger refers to (that require no special break-in, and can utilize oil from the first start with the best wear #s) don't have that limitation.

6 VOLTS/POS. GRD. NW INDIANA

Made a call to Mobil 1 and found their high rated 0W40 with 127,221 psi has 1100 ppm in zinc. This was not stated in the article and really don't know how safe it would be in a yblock but had their highest rated psi of any oil.


-Gary Burnette-

540 rat has been staging a marathon discussion over on SpeedTalk..  He has been called out on his methodology and motives by a lot of guys who think his conclusions don't square with their beliefs.. I buy quite a bit of what he is saying. 540 rat has spent his own money testing many oils for their chemical analysis and posted results.. I actually sent him two local discount store oils that I use in my everyday stuff.. They fell mid pack on the psi test ahead of some of the big name stuff  At 2.50 qt I will keep using it  lol

He is very thorough in his testing methods.. Whether they are valid for a running engine is an open question.

RB

This is all real interesting but the real question is how many of us has had an engine failure related to the oil they use? I've been a member here for some time and I can't recall anyone posting "don't use brand X oil because my engine just failed because of it".

Durham Missouri

So the 20w50 racing oils are out for y block use? I was thinking about using the Valoline VR1 oil for my next oil change in that weight. I'm using Bradd Penn 20w50 right now but at $50 a oil change its a little pricey. I may try the 0w40 Mobile that Speedpro56 mentioned.

Durham Missouri

20w50 should be fine for a Y block.  It should not be needed for a fresh rebuild, though.

0w40 could be too thin.

Here is a website that allows you to compare the viscocity of an oil at given operating temperature.  There can be quite a difference between similar grades.  One brand of 15w40, for instance, could be thicker at a given operating temperature than another brand of 15w40 at that same temperature.  You need the technical data sheet, which you can get from the oil manufacturer.

http://www.jiskoot.com/services/calculations/viscosity-temp/



Lawrenceville, GA

I was doing some more research on this and run across a post where someone recommend mixing 10w30 with 20w50 to achieve a 15w40 oil weight. Is this a viable option? The post was about the same brand oil just different weights.

Durham Missouri

No idea but most major brands have a 10w40 or 15w40 oil.  Use that and take out the guess work.



Lawrenceville, GA

The Mobil 1 tech for what it's worth still recommended 15W50 for flat tappets with 1300 ppm zinc. It seems to me we have several options to choose from and I can't say if 0W40 is safe or not, I've never used it and from what I can find out it's relatively new even thou the article gave it the highest marks of all the oils tested.
     For now I'm using Amsoil Z- Rod 10W-30 high zinc formula with 1400 ppm zinc with no issues. Applications API, SL, SJ and earlier.


-Gary Burnette-