What is the best motor oil to use in my slant 6? Do these high milage oils make a difference? I have 130,000 miles on mine.

Mister Search Feature is your friend!
Or go to www.bobistheoilguy.com

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If it was easy, everybody would be doing it.

See this thread, and read the big article linked from there. Don't use "high mileage" oil unless you want to change all your engine's rubber seals soon. Use a NAPA Gold #1806 oil filter, never a Fram.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

generally the slants do good with a hdeo, (heavy duty engine oil). Such as Rotella T, or Delvac or other such heavy duty diesel or heavy duty gas oils. These oils have a higher content of zddp. The flat tappet engine slant needs the higher zddp to keep from scaring. The newe oils have cut zddp dramaticaly, which is not a big deal for the new motors but for ours it is you need the higher counts of zddp. here are some good high content zddp moly oils,
Redline has a good amount, royal purpl race oils (not the regular). Amsoil hdd 5w-30, mobil 1 0w-40, mobil 5w-50 mobil 1 truck and suv, mobil 1 diesel, Rotella, and Rotella T, Delvac and delvac 1, and more. Bob is the oil guy forum will give you loads of information..... hope this helps............

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87 Chrysler Fifth Avenue 318
82 Dodge diplomat 318
74 Dodge dart swinger 225 /6
55 Chrysler windsor poly 301

Mopar-or-no-car, your recommendations are similar to what I used to think before I got educated on the matter. Any kind of 50wt oil (5w50, 15w50, 20w50) is the wrong choice except on a seriously whipped worn-out engine, and the "old engines need ZDDP" thing is not true as stated — as I say, I used to think that, too, but it's not so. The issue is a great deal more complicated than that. Go read the linked thread, and go read the linked article.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I didn't necessarily recommend 50 weight as a blanket, I gave some examples of heavy duty engine oil. there is also 30 weight in my post and zddp and moly are VERY important to a flat tappet non roller motor, anyone telling you different I feel at least is missing the needed protection for your slant six. I suggest more reading on bob is the oil guy forum on such issues. I have been selling motor oil for 13 years. I have done countless used oil analysis. I have jeep 4.0l and slants Most my motors are inliners, and I can tell you from experience on these motors the higher moly and zddp are what is required. I have run the sm and sl oils as well as the hdeo oils. I have run mobil 1 5w-30 sm, chevron 10w-30 sm rated, Amsoil Heavy duty diesel 5w-30 (HDEO not SM) and rotella T 5w-40 HDEO not sm rated. They all had used oil analysis performed, guess which ones came back with less wear metals or less engine wear? The hdeo oils reduced wear metals by 20-35 percent !!! and thats comparing them to a top performing sm oil Mobil 1 5w-30 a POA full synthetic with rotella group 3 conventional oil...Flat out the oils with a higher zddp or moly content come back with significantly less wear. The jeep 4.0l guys are having engine failures galore with the wrong oils and engine builders and cam companies are not warrantying unless the correct heavy duty oil has been used. Its up to you on what you want to run but making a statement that zinc zddp or moly isnt what its cracked up to be isnt true. as these items are specifically for high loading index, that is what it is added to the oil for. Modern engines which have much tighter tolerances roller engines and stricter emissions standards and tighter epa mileage regulations require the move to the new sm rated oils. New engines do NOT require a high shear stability index as do the old Flat tappet engines. The only reason zinc or zddp has been reduced is for tightening emissions. the oil has no need for as much of an expensive additive anymore. The epa doesn't want zddp anymore and mostly because new catalytic converter emissions laws mandated by the federal government require catalytic converters to now be warrantied to last 150,000 miles instead of the 100,000. Zddp is bad for cats so reformulated oils with less zddp had to be created, hence the move for an Sj-Sl rated oil to the new SM

just my .002

http://www.bobistheoilguy.com/forums/ub ... 49&fpart=1

http://www.bobistheoilguy.com/forums/ub ... ost1265603

http://www.bobistheoilguy.com/forums/ub ... 17&fpart=1

http://www.hotrod.com/techarticles/engi ... index.html

http://www.centralpastreetmachines.org/ ... 20Oil.html

http://www.cranecams.com/?show=newsLetters&no=260


FROM MOBIL THEMSELVES ADMITTING SM DOESNT CUT IT
http://www.mobiloil.com/USA-English/Mot ... gines.aspx

http://www.motorists.org/blog/warning-i ... carefully/

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87 Chrysler Fifth Avenue 318
82 Dodge diplomat 318
74 Dodge dart swinger 225 /6
55 Chrysler windsor poly 301

That is not necessarily correct. ZDDP and moly are not the only oil constituents capable of protecting sliding-friction junctions like cam lobes in non-roller-lifter engines. Never stop learning!

Do I dare ask what kind of oil you've been selling for 13 years?

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

please enlighten me as to what the new sm oils have for high sheer stability not phosporus since its in direct relation to zddp no or low levels of zddp = lo phos, so what has an effect on shear stability besides moly zddp and phos ? let me know, also schaeffers amsoil, torco, mobil1 redline, just thought it was amsoil eh wrong.

Dan I respect you highly heck I've bought lighting products off your website. I have come to listen to anything you say on this board there is no doubt when it comes to the slant you know what you are talking about. But oil is my passion I have been selling it for years as well as closely related to it in racing. I have been to numerous lubrication conferences and training, I guess you could say I am an oil nerd. I love learning more of all aspects of lubrication and oil. I don't know everything about oil. But I understand a lot about it and its additive packages. I have provided some useful links in the last two posts. My advice to everyone is to do searches look at my links spend some time on bob is the oil guy forums, do used oil analysis to see what your engine really responds well to. Will a sm rated oil protect your engine ??? probably, you have a slant six so yes the possibility of a lubrication related failure is low unless you are running an high lift cam. But why settle for reduced wear protection if you can buy a product that protects much better for the same price ???? If so so protection is good enough don't worry what you run just go buy dollar store oil, but if you want the best protection for your slant do the research, do the used oil analysis and you decide. Oh yeah one last note, my passion for oil started long ago, before selling it I worked for Blackstone laboratories to put myself through school (a oil analysis firm) so I am well aware of what a good oil can do for wear numbers, as well as actual engine longevity.

http://www.blackstone-labs.com/

http://www.mobiloil.com/USA-English/Mot ... _Cars.aspx

http://www.mobiloil.com/USA-English/Mot ... hrods.aspx

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87 Chrysler Fifth Avenue 318
82 Dodge diplomat 318
74 Dodge dart swinger 225 /6
55 Chrysler windsor poly 301

I respect your experience and knowledge, but:

1. Please don't put words in my mouth — respond to what I actually say, not what you think I think.

2. Please go read the linked article — don't just assume what it does and doesn't say.

Then we can talk.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I read the linked article upon first request, seems to be inconclusive to me, I do not see how it answers anything or provides any meaningful proof. I still wait for data that an oil with little to no moly zddp or phos, can provide high levels of shear protection and stability...........

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87 Chrysler Fifth Avenue 318
82 Dodge diplomat 318
74 Dodge dart swinger 225 /6
55 Chrysler windsor poly 301

If you're not seeing any valuable content in the article, you might want to try reading it again. "Proof" is in the domain of the marketeer — if we're discussing facts and science, reality is better described in terms of tendency, demonstration, and suggestion.
H'mm. No, please take a closer look at what they actually say. Also take note that their SM Mobil-1 contains 800ppm of Phosphorus, then do a search of the literature I'm sure you have close at hand and take a look at what's considered adequate for protection of highly-stressed sliding-friction junctions.

I'd like to ask you also to please re-read what I have said, and take careful note of what I haven't said, and look at my comments about ZDDP in other threads. If you read carefully, you'll see we don't disagree nearly as much as you presently seem to think we do. I'd also still be interested to know what kind of oil you sell. But this has all the makings of a pointless, drawn-out argument where we go round and round and round, talking past each other and not effectively listening; not a very effective use of time and bytes, so unless the conversation veers sharply away from that direction, I'll close here.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Its is no such thing, I enjoy speaking of oil. The new SM oils do not have near the shear ability of the sl and older, but as with all humans I can be wrong. I just was eager to see a sm that had a high shear rating, To my knowledge there isn't one. I have yet to find an additive other than zddp moly or phos that significantly helps with sheer. I am not trying to start any arguments of any kind. I just would like everyone to feel more confident and educated about the oil used in there slants. I encourage everyone to do some research then decide what oil they think they should use. I also encourage used oil analysis as there is no way to know if your oils really is a good match for your engine without it.

I have read it three times still see no real value,here is what I sell as stated four posts ago "schaeffers amsoil, torco, mobil1 redline, just thought it was amsoil eh wrong ".
I am asking for actual proof used oil analysis not what makes you feel warm and fuzzy but real factual scientific chemical proof that a non zddp enhanced oil can provide the shear stability and lower wear numbers of a high zddp or heavy duty engine oil.
Our engines being flat tappet are considered a high shear load engine, if you put a bigger higher lift cam in it increases the shear load even more. seems to me that to er on the safe side of the oil choice and select something considered overkill, is less likely to leave you on the side of the road or rebuilding. I do agree that this thread is dead unless someone has useful questions for me or would like to discuss heavy duty engine oils and the vast benefits they provide our engines......

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87 Chrysler Fifth Avenue 318
82 Dodge diplomat 318
74 Dodge dart swinger 225 /6
55 Chrysler windsor poly 301

Only two items that has come up recently. A racer friend wiped a lobe off a new racing camshaft right away. major cam corp. tech person said you used the wrong oil for break in and it did not have enuff zinc in the oil. thats all for that.
Erson camshafts now recomends their break in lube with zddp for their flat tapet camshafts.
PS my racer friend was not breaking in a Erson camshaft. Thanks Ron Parker





It Aint Over Until I Win

the crane cam I just bought for my smallblock recomends not using an sm or sl rated oil and suggest brad penn and one other brand I cant remember + break in additive when breaking the cam in. I've been using brad penn in my rebuilt slant with no problems oil pressure is 45- 50 psi hot or cold at all rpms

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64' Valiant Signet 5.9, 64' Dart 170 moredoor 3.7, 67' A100 3.7, 00' Dakota SLT 4.7

My understanding that it isn't a question of sheer stability at all. ZDDP was used to prevent direct metal-to-metal contact under extremely high pressure, not unlike (but still a little different than) the way additives in "EP" (extreme pressure) greases and oils work. The ZDDP additive actually gets consumed whenever it does its job, so there had to be enough in the oil to last the expected change interval. It only works AFTER all the oil has been squeezed out of the metal-metal junction.

There are other additives that do that now, but I honestly don't know the chemistry.

As for Moly (Molybdenum disulfide) additives that oils like Royal Purple utilize- the question there to me is whether there is a risk of the additive, which is a solid, precipitating out of the oil. Apparently its not a huge problem, but I still question how effective it is over time when there is an oil filter in the system.


And as for the whole ZDDP scare... there was an article on the Crane Cams website where they said right up front that SEVERAL things all happened at once, including a batch of cam and/or lifter materials that were very substandard. ZDDP reduction happened at the same time- well, changing 2 things at once prevents you from being able to separate the cause and effect. Crane (and other cam makers) did the smart thing and covered their bases several different ways- the recommended high-ZDDP break in oil, changed their lifter to have a center-face oiling hole to add oil to the lifter/cam junction, and fixed the supplier problem. Were all 3 steps NECESSARY? Probably not, one or two alone might have worked. The fact that there hasn't been a big rash of cam failures out in the general fleet tells me that ZDDP replacements are working reasonably well.

That said... I use Rotella Synthetic in my engines with flat cams Just in case. But you should also know that the C-prefix oils (diesel engine oils like Rotella and Mobil Delvac) have also cut WAY back on ZDDP and will cut more in the future. Rotella has gone from a CI rating to a CJ rating in the last couple of years, and the CK rating will no doubt have even less ZDDP. I

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