rotarygod

We are at a time where even the cheapest gas station generic brand oil is probably just fine to use. Something that wasn't true 20 years ago. I'm not going to use them though but in general just pick an oil and use it. Forget UOAs and trying to learn the fine details of the book from reading just the back cover. Gasoline is by far the dirtiest, most harmful carbon depositing thing you put in the engine anyways.

rotarygod

I didn't say his readings are inaccurate or misleading. I'm saying they are irrelevant.

paimon.soror

iTrader: (15)

I think this is the key point here. UOA's are only as good as the engine that they apply to.

Not so much that the number on paper bothers me, vs if I am paying the premium price why not make sure I am getting the most for my money ... protection and stability.

RIWWP

iTrader: (2)

I'm having trouble understanding your point of view on that.

In my head, oil is anti-wear, anti-heat lifeblood of the engine. Any wear will leave particles that are picked up by the oil, and can be tested for. Consecutive testing that shows lower wear rates for a given engine and driving environment appears to exactly define the effectiveness of the oil. Ignore viscosity, if oil A is showing a higher rate of wear on the engine (through the presence of more wear elements) than oil B, I would say that oil A is less effective than oil B.

What am I missing?

rotarygod

An oil that does it's job is one that protects. An oil that is stable is one that continues to do it's job when needed. How does a number on a piece of paper change that? If it worked fine before you knew what that reading was, why does seeing it written suddenly change your opinion?

paimon.soror

iTrader: (15)

And exactly how would one ever be able to tell if an oil "worked fine"...

Just because the engine is running, doesn't mean it is "working fine"

RIWWP

iTrader: (2)

Yes, exactly. Making the assumption that the oil is "working fine" just because your engine hasn't seized is pretty short sighted.

What other test would you propose to show that it's working fine? Butt dyno and "because my Dad did" are off the table

rotarygod

I would generally agree with that conclusion but I strongly have doubts when those reports will try to convince you that it is from bearing wear which many of them will. Bearings don't wear. They don't break in. They should never touch. There always seems to be something more that UOA's just don't tell. Keep in mind that RP claims micro polishing of surfaces including bearings which has to be from the oil and not direct metal to metal contact if true. If in fact that oil does have that property then it would most likely show higher wear metals in earlier oil changes and decrease with each oil change. That's how you test their claim and probably the best way to test oils against other oils. Run 5 oil changes of each and test each for comparison. You'll more accurately be able to draw conclusions this way.

rotarygod

I've got a couple hundred thousand miles on synthetics with no problems. That in itself is pretty conclusive. I have also rebuilt engines to port them that have used synthetics and have seen wear inside of them and found the biggest variable in engine health today has almost nothing to do with the oil used but rather how it was driven. The engines in worst shape will be those driven most gently. How will an oil analysis draw this conclusion? Renesis related failures are primarily due to this and design flaws in the engine itself.

9krpmrx8

iTrader: (46)

Of course a UOA doesn't tell you everything but it sure can identify a potential problem (seen in both my and Shadycrew31's car when we sent samples without telling Blackstone there was a problem) and it does give you an idea of how the oil is holding up and how your engine is doing.

Now if you change your oil every 3,000 miles then it really is a non issue running a Dino oil. And I agree that even though the cst may be lower, it is still working just fine. But, if I am going to pay for a premium product then I want the one that degrades the least during my OIC.

My thought process may be wrong but it makes me feel better knowing that my Mobil1 has all the necessary certifications and has degraded little during my oil change interval.

RIWWP

iTrader: (2)

So...what's this:
http://4.bp.blogspot.com/_V117a7r89y...aring+wear.JPG
https://www.rx8club.com/attachments/...-england-2-jpg

"Should never touch" isn't the same as "Does never touch". You are correct that they shouldn't, and this is where the oil actually matters, some will allow it, some will not.

RX-8s regularly have copper exposed on the bearings. This can only have come from wear, unless you claim that they were produced that way.

9krpmrx8

iTrader: (46)

ok.................

RIWWP

iTrader: (2)

I 100% agree that the choice of oil type, viscosity, and brand will almost certainly NOT be what kills your engine, OR what saves it. It's far more likely to die of any one of a plethora of other causes. It does certainly add a level of indifference to what oil to select, because it's probably not going to matter.

Perhaps this is what you meant by "irrelevant"?


I still see a value in selecting a better oil for the engine though. Even if it's not going to extend the life of the engine any farther. I think most people would agree with that. Your choice of using synthetics for decades says that you agree too

Wanting to know what oils perform better than others is why the tests are not irrelevant. The whole argument might be, but within the argument, the point is still valuable.

9krpmrx8

iTrader: (46)

As for the bearings. Well at this point I have been a part of a few Renesis tear downs and I have seen copper bearing wear on every engine that ran 5W-20. A couple were well maintained and a couple were not or the history was unknown.

Houstonrx8er maintains his car even better than I do and we both had failures at under 40k. Different methods of failure (neither actually was driven to complete failure) but we both have the same driving style, type of driving, and live in the same environment and yet he had pretty severe bearing wear running 5W-20 Castrol GTX and I had almost no wear running Mobil1 0W-40 (since break in). We will have another engine with about 12k-15k on it from Hoss-05 that has only seen Mobil1 0W-40 torn apart soon and I would bet my left nut that the bearings will look good in that engine as well.

TeamRX8

iTrader: (25)

what is causing the wear is where most everyone has gone wrong on figuring it out, once the S2 engine tear downs start you'll see that oil pressure mods aren't addressing the culprit, oil weight will help some but it's just a bandaid covering up a symptom ...

9krpmrx8

iTrader: (46)

Yeah oil choice is definitely not the only reason bearing wear is happening but oil choice does seem to play a role. Engine balancing is a part of it too I think.

RIWWP

iTrader: (2)

Agreed.

rotarygod

That may prove that those oils are too light. Oil gets very hot inside of a rotary. For every 10 degrees you go above 160 degrees F, you half the effective oil life. This is a general oil truth. Think about it for a while and why RB recommends that oil never get above 210 degrees F entering an engine. If this oil is already thin and higher temperatures make it even thinner, breakdown will only make things worse. The oil viscosity may still be intact but some of the additive package is degrading causing other problems. I can fully understand an oil being too thin to work well for a long time. I certainly feel that running a thicker oil will allow the protection provided by the oil to last longer. When I tried 5W20 in my older rotary, a no no on those, I found that it felt fine initially but the smoothness was gone after about 1000 miles. 20W50 felt far smoother for far longer. Now was this a result of the brand of oil or the weight of it? After years of playing with various oils I've settled back to full synthetic 20W50. I defend RP because they are most often attacked but I really like Redline and Amsoil as well. If I have a used rotary where it's previous oil was unknown I'll stick with Havoline or Castrol conventional. I love those oils too. Am I suggesting that you guys run 20W50 in a Renesis? No but I wouldn't hesitate to. Then again I'd probably have to ask the oil manufacturer if they'd pay for my engine if I blew it up. What a ridiculous argument.

rotarygod

Hopefully we can all agree that a quality oil of adequate viscosity that is kept cool enough is the goal. There seems to be some disagreement on which oils are quality but I've named my top 5, 2 of which are conventional. I think a big problem is that some are trying to blame inherent engine design flaws on their oil and are looking for any excuse to blame the oil rather than admitting you all drive am inconsistent engine with design problems. When someone blows an engine people immediately want to know what oil they used since it had to be the culprit.

There were 3 problems with the Renesis when it came out. When there are multiple issues can be tough to diagnose and forming a wrong conclusion becomes very easy. The first problem started with the FD RX-7 and is actually the fault of the car design and not the engine. Your cooling systems suck. A larger radiator will certainly help but you still need to get that hot air out. This concern is secondary though to your oil cooling system. Those cars should have all come with dual coolers and most do. Airflow through them could be improved though and a lack of fan pulling air through them when the vehicle isn't moving isn't doing you any favors. Your oil temps average higher in the system than older rotaries. There is another reason for this though.

The second problem is that you have side exhaust port rotaries. This is design and you're stuck with them. For all of the benefits of then they come with very big drawbacks. One is the easy tendency to clog with carbon (from your gasoline not your oil metering) which can cause side seal issues. Less exhaust heat leaves the engine as well. Some of this is converted into power and some of it goes into your oil and water cooling systems causing them to take higher loads.

The third issue is the only one that was dealt with by Mazda on the S2 which is the lack of oil metering to the center of the apex seals. Some feel that this solved nothing but again when you have multiple problems and only address one, you still have problems. You can cool your oil effectively. You can change it often. You can run a higher viscosity. You can upgrade your oil and water cooling systems but at the end of the day you've still got a side exhaust port which means while you may never see a problem, you've always got more uncertainty than older engines. My RX-7 has great oil and water cooling systems. I've found its engine to be extraordinarily tough to hurt. They are just insanely durable as rotaries should be. Sometimes the unknown you are searching for isn't where you want it to be. You've all got it though. You just need to come to terms with what it is.

paimon.soror

iTrader: (15)

This is by far my favorite flaw lol ... Yamamoto's book blatantly says "side port exhaust sucks dont use it, etc etc" ... Mazda: **** it, what could hurt.

shadycrew31

iTrader: (6)

The first and last problem is that I run a turbo...

Everything else is a moot point.

9krpmrx8

iTrader: (46)

I can confirm one thing. Fans (dual or single) on the oil coolers do absolutely nothing at low speeds or high speeds to lower oil temps, even high quality Spal units.

The factory oil coolers are very efficient and need not be replaced unless you are tracking a turbocharged engine. The only improvements that can be made to the stock dual cooler setup are with the lines and by removing the factory oil cooler thermostats (not ideal if you live in a cold environment). And if you go with custom lines, a high quality oil thermostat is ideal.

With my current setup (custom -10AN lines, oil thermostat, stock drivers side cooler with no thermo, higher oil pressure, and a center mount aftermarket cooler) when pushing it in 90F+ weather with the turbo adding heat, I cannot get my oil temps above 210-215F max and they generally sit at 200-210F when driving hard. When I was NA on the 100% stock cooler setup I could easily get the oil to 230F+ during hard driving in the summer. With my single large Fluidyne setup (first custom setup) temps would max out at 220F-ish.

Coolant temps are about the same as the oil temps for me as well when pushed hard with the turbo also adding heat to that. During the recent hot days I have seen a high of 218F max on coolant temps when pushing it and during traffic (or both ) I am running and aftermarket radiator, a secondary radiator (with a fan that is also useless), Mazmart water pump, Mazmart thermostat, and 75% Glycol/25% water mix.

The changes/fixes made to the Series II engine kind of speak for themselves as far as I am concerned and they seem to be holding up well. But the side exhaust ports are an issue for sure and there is nothing you can do about that except possibly doing a hybrid setup and that makes little sense to me unless you have money to burn or have the resources to play with that.

Karack

considering i have to add as much oil to the car as i do per oil change the car basically eats twice as much oil as a conventional piston engine does in 3k miles, and even if i did run an expensive synthetic it would still be fouled by 3k.

think i'm going to spend $80-100 in engine oil every 3k miles? no. because you could afford to drop in a brand new engine in about 2 years based off the additional you spent on engine oil alone..

the bearings aren't the common failure point anyways, it is the seals and housings and how exactly does synthetic protect these engines more in that respect? they don't.

if these so called superior oils make you sleep better at night, sobeit. plenty of people have used the most expensive oils and filters and still have gone through several engines in a rather short span. that is the design flaw mentioned and what people should be prepared for, it is the combustion lubrication aspect, not the crankcase and never has been. even those pictures i saw of excessive copper showing, those engines could have still lived twice the lifespan they had been torn down at. the thinner oil causes premature wear and can be remedied by, dun dun dun.. thicker weight oils. i don't run 5-20 in my car, because it is older and tired and i realize this so it is supplemented with 10-30 due to mileage.

9krpmrx8

iTrader: (46)

Well, if you know where I can get a brand new engine for $1,000.00- $2,000.00 let me know

I typically get Mobil1 deals in the $35.00 range so it's not much more than normal oil changes and I run a SOHN adapter so I don't burn oil.

Karack

i know of several places where you can buy a rebuilt engine for $2k.

Mobil1 also is the lowest tier synthetic, barely a step up from dino oil.

even the SOHN adapter still doesn't aid much in the side seal issue which is the major design flaw in the engine. too much heat is placed on the side seals versus the old PP exhaust engines. i often wonder if ceramic would be able to hold up well enough but they would be insanely pricey to produce.