Another oil thread

#1

I’ve been spending a bunch of time reading more about oil lately. I came across this…

http://getresponse.com/click.html?x=a62b&lc=rYq0&mc=f&s=GeVAT&y=j&

It’s a lot of info and it’s not something that can be interpreted at a glance. Also, it lacks info on anti-wear additives like ZDDP and Boron, and that’s a pretty glaring omission. It’s also based on manuf provided data and not oil analysis and there’s been all sorts of cases where manuf data has proven to be incorrect. With those caveats in mind, it’s the best single source of info on oil a person’s going to find.

For our purposes, focus on HTHS (high temp shear) and 100deg Visc (cSt). Find some solutions that appeal to you, then research the anti-wear properties of that oil elseware. Note also that race oils don’t have much detergent so you have change them often, and diesel oils don’t have much anti-foam in their additive package. Diesel oils that are marketed as “mixed fleet” (gas and oil) should have enough anti-foam to work in a high reving gas engine.

Here’s a couple common oils, some data from the spreadsheet, and how to interpret it.

Oil, HTHS, 100deg Visc
Mobil1 15W50, 4.5, 18.1
Redline 15W50, 5.8, 19.6
Castrol Syntec 15W50, 3.7, 17.4
Royal Purple 15W50, 3.7, 20.2
AMSOIL 20W50 HP, 5, 18.9
Valvoline VR-1, 3.7, 20.5

Interpretation. HTHS is a decent measure of the oil’s ability to protect bearings. It doesn’t tell us much about cam, rocker, ring or cylinder wear tho. The worst HTHS you can have and still be labeled a 20W50 is 3.7. Note Valvoline (which I have been using), Castrol and Royal Purple.

100deg C viscosity is a measure of how thin the oil is at operating temp. Thin means more slightly more power. Note that Vavoline and Royal Purple are fairly thick at 100deg.

When OEM’s spec an oil viscosity, what they are really doing is specing an HTHS. The viscosity chosen is a result of that. For example, BMW could say “we want an min HTHS of 3.5, and in order to get that we’re going to spec an xW50 oil.” I’ve made the mistake over the past couple of years of getting too wrapped up in oil pressure. A thick oil provided enough flow resistance at 100deg C that the OP gauge said 55psi and I was happy. But that’s the wrong way to look at it. The objective is good HTHS, as far as the bearings are concerned. All the oil pump does is get the oil to where it needs to go. The feed pressure of the pump isn’t really related to the pressure of the oil inside of the bearing itself.

What this means is that Redline 15W40 with an HTHS of 4.7 is a better oil for the M20 then my Valvoline VR-1 20W50 with an HTHS of 3.7. My oil pressure with Redline 15W40 is going to read lower because it’s a thinner oil, but that’s ok.

The time to worry about oil pressure is when your buddies are getting 55psi with a certain oil but you only get 45psi with it.

I emphasise again that this doesn’t address anti-wear additives in the oil. There aren’t that many oils with decent amounts of ZDDP and the various alternatives for ZDDP all seem to suck.

Over at Pelican there is a ~68 page thread from 2007 on oil. It’s a terrific thread, even if a lot of the information is out of date. Our own Don the FL based SpecE30 guy, has multiple posts in there. Don really knows what he is talking about.

I’ve learned so much over the past week that I have to do a lot of updating on the oil page of my web site.

#2

Ranger wrote:

Deck chairs on the Titanic. :slight_smile:

I’ve got $100 to put towards “Ranger’s Unmolested Engine Test Hypothesis Evaluation and Demonstration Answer Yielder” (aka RUE THE DAY).

I am collecting a fund to purchase an unmolested 150k - 200k junkyard engine for Ranger. I am looking for an experienced mechanic who can install a crank scraper in conditions cleaner than a gravel driveway and do a valve adjustment to spec. The motor must be run with Mobil1 between the half and full marks – but not over. No additional oiling devices will be permitted. One oil pressure gauge may be connected using a Factory3 sandwich plate. Other than checking the oil, Ranger will be prohibited from touching anything in the engine bay.

If that motor survives four race weekends without oil-related failure, Ranger must agree to never post another oil-related thread on SpecE30.com. If it does not survive, Ranger gets a free test bed for his latest hypothesis.

Who is with me?:laugh:

#3

I’ll contribute the engine seals to prevent ‘tampering’…
:laugh:

#4

Been there, done that, and the engine continues to live in Laura’s #911. Swapped in February of 2009.Crank scraper, no OP gauge, if it blows up, it blows up.
it is good for 154/154 on the dyno.

My best engine was the junkyard motor of the 8 car at 160/160. But, I blowed it up with a coolant leak.

My vote is for the junkyard engine.So, I’ve got three of them running around in street cars just waiting to be needed.
Upon need, I’ll compression and leakdown the engines to assess their race-worthyness.

Too bad this theory did not work for Scott in the “great Cmp Engine Swap of May 2009.”

Motor oil of choice: 0w20 blend with some truck diesel synthetic stuff. My logic: I had an ex-oil company engineer do some technical writing for my magazine and that was his low-buck, really works, you should see what the NASCAR guys do, recommendation.

RP

#5

Steve D wrote:

[quote]Other than checking the oil, Ranger will be prohibited from touching anything in the engine bay.

Who is with me?:laugh:[/quote]

This includes “monitoring” the engine (via 362,342 gauges, fittings and sensors) too right?

I have a brand new head gasket still in the wrapper to contribute to the cause.

#6

TheRedBaron wrote:

[quote]This includes “monitoring” the engine (via 362,342 gauges, fittings and sensors) too right?[/quote] Right. Oil pressure and water temp are the only permitted gauges/sensors.

[quote] I have a brand new head gasket still in the wrapper to contribute to the cause.[/quote] No, no, no! He gets to take off the oil pan and the valve cover (if done in a real shop). That is IT! Belts, hoses, filters are OK. But no way in hell are we letting him touch head bolts or any other internals.:laugh:

#7

Speaking of oil mayhem…I decided the other day to simplify my oiling system and recover the thermostat by putting the OEM oil filter adapter back on. I had thought that it was going to be necessary to take the OEM oil filter thing to a machineshop so they could weld AN fittings to it. But I figured out this morning that you can get an adapter that will fit.

Therefore anyone that wants to put an aftermarket oil cooler on can do it simply by putting a couple M18 X 1.5 to -10AN adapters on to their oil filter thing and plumb in their new cooler. Doesn’t get easier then that.

Personally, I like Robert’s engine approach. It was bad luck that the CMP motor turned out to be a 323 frankenstein, and then have bearing problems, but shit happens.

#8

I am betting a case of beer on Ranger putting his tinkering fingers on that engine BEFORE the first race weekend.B)
Keep the faith Scott, keep the faith. :lol:

#9

Here’s another issue…The link between oil visc and hp is weak. That is to say, thin oils don’t necessarily make more power. There seems to be such difficulty understanding why one oil results in more power then another, that folks resort to dyno testing INSTEAD of understanding. There’s lots of smart folks that have done extensive oil and hp testing and they will often say “this oil resulted in more hp, but we’re not precisely sure why”.

Thin oil means less hp required for the oil pump, and less hp required to turn the bearing. But those are not necessarily where you’re going to find efficiency. Each rocker is pressed on to the cam with 180lb (approx.) springs, and the piston rings are scraping up and down the cylinder walls. The lubrication mechanisms in these situations aren’t nearly as efficient as what’s going on inside of a bearing. Therefore there is hp to be found outside of visc comparisons.

Some oils use high moly content to make the top end and cylinder walls slippery, but a lot of folks criticize high moly content. I don’t know what the truth is there.

The bottom line is that lower weight oils won’t necessarily result in a hp gain. There’s lots of oil vs. hp studies that ended up with a winner that was not the lightest oil.

#10

Steve D wrote:

[quote]Ranger wrote:

Deck chairs on the Titanic. :slight_smile:

I’ve got $100 to put towards “Ranger’s Unmolested Engine Test Hypothesis Evaluation and Demonstration Answer Yielder” (aka RUE THE DAY).

I am collecting a fund to purchase an unmolested 150k - 200k junkyard engine for Ranger. I am looking for an experienced mechanic who can install a crank scraper in conditions cleaner than a gravel driveway and do a valve adjustment to spec. The motor must be run with Mobil1 between the half and full marks – but not over. No additional oiling devices will be permitted. One oil pressure gauge may be connected using a Factory3 sandwich plate. Other than checking the oil, Ranger will be prohibited from touching anything in the engine bay.

If that motor survives four race weekends without oil-related failure, Ranger must agree to never post another oil-related thread on SpecE30.com. If it does not survive, Ranger gets a free test bed for his latest hypothesis.

Who is with me?:laugh:[/quote]
I’ve offered one of my spare engines to Scott, but so far he hasn’t taken me up on it. In light of your comments I think I’d specify that it use the OE oil cooler set up and is permitted to have only an oil pressure (at the pressure switch location) and temperature gage. Nor is Scott allowed to open up the engine in any way.

So I’m in!

#11

From memory they were M20x1.5 or M22x1.5 when I did mine that way Scott…

Ranger wrote:

[quote]…But I figured out this morning that you can get an adapter that will fit.

Therefore anyone that wants to put an aftermarket oil cooler on can do it simply by putting a couple M18 X 1.5 to -10AN adapters on to their oil filter thing and plumb in their new cooler. Doesn’t get easier then that…[/quote]

#12

Just spoke to my Father… you say - wtf… well, he’s been a Chemical Engineer for large Oil Companies for decades working in Process Design for companies like… um Mobile.

Anyway… What he says carries some weight, and I think is of particular interest to Ranger.

The Oil designed today totally out spec’s the oil produced at the time of the creation of the M20B25. The Oil is so far superior, that any of the Oils we could possibly choose would perform leagues better than the Oil that was used in the R&D for the engine we all use in the series we race in.

So, according to Dad… and please take this with as much speculative reasoning you give anything you read on the internet… according to the one known as “Dad” use the Dyno as your measure of the Oil you pick as much as any other method for choosing the gooey stuff.

#13

Where do I find what the rest of those numbers mean without buying the book.

Don’t say google. I already tried.

#14

No offense intended but in order to talk about oil a person has to talk about physical properties like visc and HTHS, and chemical properties like ZDDP, Boron, and Calcium. I’m no tribiologist nor have I personally conducted the various bearing and cam tests that I read about. But I am a mechanical engineer and I took an assload of chemistry so I can usually understand what I’m reading.

As long as folks explain the science behind their assertion than it’s worth considering. But the science behind the assertion does have to be explained.

There most certainly are oils now that are far better then the oils from 20yrs ago. But there’s a lot of inferior oils too. And there’s the ZDDP reductions that the last two oil certifications have mandated. And finally, oil companies aren’t always accurate in their claims on the chemistry of their oil.

There’s a lot of misunderstandings re. oil. For example, oil companies will tell you that the latest SL certification is backwards compatible for all engines. But when you actually dig into the SAE papers you find that the “backwards compatible” claim is bogus. The formal process that resulted in the SL certification explicitly excluded testing on older engines stating “they aren’t made any more”.

Some of the issue is valve springs. Newer motors with 3 and 4 valves have light springs around 100lbs. Older motors with 2 valves had heavier springs. Ours are around 180lbs IIRC, and that’s quite a bit. That is enough that serious attention has to be paid to antiwear additives. So to some extend more modern engines can get away with less anti-wear, but not our engine.

The link below is to a hellacious thread at Pelican. It’s 67 pages long and I’ve been reading on it for a couple days now. It’s a gold mine of info, even if a lot of the specifics are dated. http://forums.pelicanparts.com/porsche-911-technical-forum/367300-ultimate-motor-oil-thread-why-we-hate-cj4-sm-oils-52.html

Based on this thread I’m going to switch oils to Brad Penn. It’s inexpensive and is very well respected. I haven’t decided on a viscosity yet tho.

Turbo, send me an email and I’ll send you the book.

#15

kgobey wrote:

[quote]

The Oil designed today totally out spec’s the oil produced at the time of the creation of the M20B25. The Oil is so far superior, that any of the Oils we could possibly choose would perform leagues better than the Oil that was used in the R&D for the engine we all use in the series we race in.

So, according to Dad… and please take this with as much speculative reasoning you give anything you read on the internet… according to the one known as “Dad” use the Dyno as your measure of the Oil you pick as much as any other method for choosing the gooey stuff.[/quote]

I agree 100%. Today’s oils (all of them) are far superior to the oils that were available all through the life cycle of our engines. And 99.5% of our engines (and many junkyard engines of today) still survive 120 MPH Autobahn runs, Mike Davidson’s rev limiter torture thorugh hog pen, and thousands upon thousands of track miles. That means our engines are pretty stout and any of today’s oils should do a pretty good job of protecting them.
Having said that, every engine is different, every e30 engine has had a different history, and why junk yard engines or street engines that have been driven 100k miles plus fail has absolutely nothing to do with the oil that is in the car today. It has more to do with wear or sludge that happened at some point, maybe 20 years ago, in the enginne’s life. It may even be due to that one in 1000 defective bearings, cams, or cranks that made it’s way to the production line. Engine failures have nothing to do with brand X or brand Y oil.

Now assuming that one has a newly rebuilt engine I agree with Ranger that the using the best HTHS synthetic oils with the best ZDDP package is a good idea. And why not use the best oil one can buy even if it merely prolongs an engine failure one more weekend. Let’s make sure we are clear. No Oil causes an engine failure, No oil can prevent an engine failure that is bound to happen anyway, and No oil can be expected to prevent failure in engine if an engine is over revved or otherwise abused.

The idea of finding the best [ul]engine[/ul] oil for max Hp is a complete wast of time. There is actually much more usable parsitic loss through trans and diff oils and if one wants to study lubricants on a dyno, this is where you should spend your time.

Per Patton, the NASCAR teams study this frequently and many teams put ultra slippery, ultra light oils in the cars (engines, trans, diffs, and even power steering) for qualifying to get that extra HP for that extra 0.001 second on the track. Does that mean we should use 0w 10w or 20w oils in the engine, trans, and diffs? Hell no. The NASCAR teams have engineers who study lubes and change lubes after every practice session. If one of those magic oils failed to lubricate an engine or a gear in a practice or qualifying session, that engine trans or rear gear is changed and a longer life oil is put in the qualifying oil’s place. We can’t keep up with such nonsense.

I am a strong believer in high ZDDP synthetics simply because it is fact that syntehtics flow better when cold an hold up better when hot. Period. There are some top quality blends and I believe Amsoil, RedLine and Royal Purple are right up there. The difference between those oils and the big name brands is almost negligible but if one wants to split hairs, the base stocks of the brands mentioned and the additive packages are a tick better than the “profit for shareholder” mega brands like the Mobil-1s, Syntecs, Valvoline and Quaker Sates of the world.

Per Ranger’s comment about the Pelican thread and Brad Penn. I have studied that thread as well and have contibuted a few times. As I state above, the differences between any of the high line oils including Brad Penn are insignificant. Personally I prefer a full synthetic PAO based oil to Pennsylvania crude for the extreme temperature performance.

I hope this perpsective is helpful.

Don Stevens
Spec E30 #80

#16

Maybe the problem is thinking about it to much. Last night you got me thinking about it and this morning at the first stoplight after about 10 minutes into my drive to work my op light came on. I pulled in and checked the level and it was full. I started it back up and realized it only comes on under 800rpm. I drove the last few miles to work and checked it an hour later and it was right at the full line. I just changed the oil about 1.5 tanks ago with gtx high mileage 10w-40. I’m hoping that my driving style along with the high detergent oil stirred up so much crap that it clogged the new filter, but I think it’s more likely that I have bigger issues. I’m going to cut the filter open as soon as it cools down enough. Funny thing is it started running strange after I changed the fuel filter a few days ago. I don’t have a working odometer but I think it’s sucked down half a tank in <50 miles, the valve-train is substantially louder, some drives I make good power and others not, and I don’t know how my oil is right at the full line at the rate that it leaks out my pan gasket.

#17

I just noticed something really important to your comparison. 3.7 is the lowest hths that a 50 grade oil can have. All of the 3.7s are in red because the information is not provided so 3.7 is put in by default. That explains why the 99 cent gas station brands like citgo and 76 do better than royal purple and many other “racing” synthetics.

#18

I replaced the filter with another fram extra guard. The 2 week old filter is very sparkly and I picked up a lot of metal off of it with a magnet. My brother said to run the new filter for a little while longer than it took for oil light to come on with the new filter and if it came on again to start calling junk yards for a new motor. It didn’t come back on after 15 minutes. I pulled the valve cover and everything looked fine. I expected missing lobes from the noise it makes now.

#19

Sparkly stuff in the oil is evidence that things in the engine are shedding metal. Which in turn means it is time for a rebuild or replacement of the engine.

#20

Further comment on the sparkly stuff and low oil pressure.

Does anyone really know if engines fail because of low oil pressure or if the oil pressure drops because if all the sparkly stuff clogging the oil pump intake? My guess is that by the time a driver notices the oil pressure drop the damage has already been done

Don