Been a while since we've had an oil thread

[MikeSchinlaub]

Man, oil is a touchy subject, isn't it? I guess it's a good thing I'm not an engine nerd, just the regular kind!

 

[nola mike]

Guess you missed the part about better reduction in foaming and corrosion protection in humid environment

I must have missed that as well. The merc and Yamaha/Honda oils were on different ends of the spectrum for foaming, and also corrosion, and weren't great for shear stability. T4 did well on everything.

 

[Pmt133]

And still a worse performer on flat tappets. Go figure.

 

[Scott Danforth]

And still a worse performer on flat tappets. Go figure.

Where do you get that?

 

[tphoyt]

I was wait for this to blow up.

 

[nola mike]

Where do you get that?

He has another video breaking down that more zinc =/= better protection. I'm see if I can find it
Around 8:00

 

[Pmt133]

Where do you get that?

There was a white paper done a while back. Took a bunch of cams in, I think small block chevys. (Note lake cites this test constantly) and then run and put under a scope and wear and particle counts measured. The diesel oils constantly had ~double the wear rate vs even current API formulations at the time. My own testing indicates the same, diesel tends to show the worst performance in gas engines and it's kind of why API went and reformulated current oils for lower detergent levels, particularly calcium. Current formulations have more than enough zinc and lack of calcium to support flat tappet engines. I would still use a break in oil for a fresh break in, but the required film strength at the interface is strong enough to support any engines already out there, broken in, with them in it.

The higher detergent loading that isn't needed in a gas engine present in diesel oil competes with the zinc on the surfaces on a chemical level. The soot loading on diesels dispersed the calcium enough where it works as needed. It's functionally always been a chemistry problem.

Now is double the wear actually a problem when, even though you can measure it, we're talking about microns? No, not really. But it's been consistently demonstrated that dropping the calcium levels is much more effective then ridiculously high zinc levels. I had read the paper in college, can no longer find it.

Delvac and rotella sheared down to a thin 30wt in my 4.3 in the boat in under 50 hours. I'm also seeing chrome and aluminum from the rings and pistons in the samples now. Tried merc this go around to see what happens. While I expect it to shear, I suspect it didn't exhibit as great of a drop in viscosity. If I do see elevated wear metals in the oil again, then something else is going on and I can't blame the diesel oil.

 

[Lou C]

I read that too and found it interesting. When I used Delo 400 straight 30 it also sheared a bit but the three varieties of the Merc oil (conventional 25/40, syn blend 25/40, syn blend 25/50) did not and this was over many years not just one test of each. This 4.3 had the roller cam from the factory though so it doesn’t need high zinc levels. I pulled out the lifters when I did the cyl heads 9 years ago and the cam lobes and roller lifters looked new! At that point it probably had at least 1500 hrs on it.
Now who actually still had a flat tappet cam engine in their stable? Well I do. 1998 Grand Cherokee 4.0. I have owned it since new so I’d notice any changes in sound over time. I have run it on 10/30 Maxlife for about the last 86,000 miles current mileage is 186,000. And those flat tappet lifters are QUIET as new! That oil has about 800 ppm of zinc. Thought of switching to VR1 10/30 which has about 1000 ppm of zinc which was the spec back when the 4.0 was in current production. But what this may show is after break in you don’t need crazy high levels of zinc for an OHV flat tappet.

 

[Lou C]

2011 test was Delo 400 straight 30
2015 was Merc conventional 25/40
2021 and 2022 was Merc syn blend 25/40
2023 and 2024 was Merc syn blend 25/50
you can see my HGs started seeping in water as shown by the sodium levels from salt water (but never showed on the dipstick or in the used oil at all) as early as 2011, before the overheat in 2013. HGs blew in 2016, fixed it 2017. And you can see how long it took the levels of sodium and wear metals to drop down to more in the normal range.
Also interesting in view of what Lake Speed said about calcium, the Delo 400 straight 30 had 3700 ppm, whereas all varieties of the Merc oil have about 2200-2400. Maybe as he says that's a factor, if the calcium actually competes with the zinc.
Keep in mind that the short block is original from 1988 it has never been taken apart, original bearings, pistons, rings, etc. So who knows how much longer it will go, lol. I guess I got my money's worth! At least 25 seasons of raw water cooling in the salt, but got filled with AF every winter not left dry except when I was doing the repairs in 2016-2017.

 

[Mc Tool]

What do you guys call a flat tappet lifter ? To me thats only the old sbc lifter style of thing , but I also have a few motors with the ohc rockers/ followers that have 2 - 3 inches of radius on the contact pad . The 2l pinto motor is notorious for chewing these out ....like if you get 90 -100k kms out of a cam and followers your doing well ( they also chew their way thru cam bearing too )
I gotta confess that I have never had my used oil tested , and the only real scientific thing I did was to check up that the zinc content wasnt going to hurt my cat converters ( one of my cars has 3 of them ffs) . I just change the oil in the cars at about 7000kms , outboards and quads hardly see more than 15 -20 hrs , 30,000kms for the auto trans's and yearly for all the diffs and gearboxes ( if they dont run in the engine oil ). what is OCD?

 

[redneck joe]

well, then there is this...

 

[alldodge]

What do you guys call a flat tappet lifter ?

Lifters that are flat steel against the cam lobe, there is no roller bearing as in a roller cam

 

[Mc Tool]

Lifters that are flat steel against the cam lobe, there is no roller bearing as in a roller cam

so something with a bit of a radius is to all intents and purpose a flat tappet ( rocker , follower ).
I have only ever commissioned 2 sbc type cam/ lifter set up and both were fairly ( .530" lift and 270° @ .050 duration ) lumpy and I used a lower than spec valve spring to run them for the 1st hour . I have seen a couple of cam/lifter that didnt last 15mins ( not mine )....never did find out what exactly was to blame .
One issue I have had with the pinto was that using hi spec synth oil ( with zinc ) with the cam/followers in mind would glaze the bores pretty damn quickly , but "running in oil " would not do the valve gear any favours