Are you still allowing for an extended idle time before driving the car? This can contribute to dilution and cause viscosity degredation.

 

Yes I still allow my car to warm up fully before I go anywhere. I did a little research based on what you mentioned before and did not find anything conclusive the cons of idling. Basically what I found was that this was an issue in older cars but not with modern vehicle PCM's(ECU's, PCU's whatever you wanna call em').

 

~7.5 litres, can't remember exactly off the top of my head, on an oil change we end up with perhaps 1/4 litre left in the system, don't bother flushing.

 

huh? I was asking phillipM.. And I did read it all, I just have a very short memory

 

I would really have to imagine that your oil capacity in conjunction with the amount of oil you're able to extract really helps to ensure your 30 weight oil is sufficient.

 

I should perform a UOA my next oil change. I too let my car idle to operating temp (at least, what the factory gauge says) before I drive it. The only reason for fuel dilution that I could think of would be due to the rich mixture during initial warm up. Whether this is an issue or not, I dunno.. If it is, I would imagine some mapping could be modified in the pcm.

 

One of the features of the COBB is being able to adjust the warm up air/fuel target. I have set mine to 13.5 which seems to work fine. Otherwise the car goes very rich at about 11:1 at warm up.

 

huh?
after the o2 sensor warms up my a/fs at warm up are in the stoic range?
OD

 

It might depend on the actual coolant temperature for how long the "warm up" period actually lasts.

I see air/fuel readings that are below 14.7:1 for about 30 seconds to a minute and then it evens out. The PCM also operates in open loop for a short period of time before hand.

All I know is altering the warm up air/fuel target does impact how the car runs initially. I had it set to nearly 15:1 on startup but I got a lot of gurgling noises because of the lean fuel target and the excessive amount of oil being dumped into the motor. The OMP runs at 30/60 for a few minutes during startup. Once I lowered it to 13.5 it went away.

 

Yeah, that's the cold start enrichment doing it's thing rather than the temperature compensation from coolant sensors.

 

i've run the reccomended 20W50 in all of my RX-7's for year and thousands of miles without a problem. Mazda switching to a thinner weight has me concerned. i currently use 5W30 in the RX-8 and have had no issues thus far..this isnt to say say that as the miles pile up, the engine will not wear..the wear is inevitable. for example, take these pics into consideration:

front stationary gear:



rear stationary gear:



this is on an 85 model year 12A. the mileage was 142K and 20W50 was the reccomended oil to be used. 10W40 in the colder months (below 32 degrees F)

this engine had a small engine mounted water to oil oil cooler. very inefficient. it was carbureted and with the choke pulled for cold start, revs were around 3K or better for extended periods. the oil was injected using a mechanical oil metering pump and was pumped into teh carb and trickled into the engine. these early engines lasted a LONG time with that setup. now we have oil injectors used to spray oil onto the rotors, tighter tolerences (hence the 5W20) and we think the rotary has gotten better with age.. it has in terms of power, efficiency, and smoothness but reliability is marginal. where did Mazda go wrong?

 

Bearing tolerances have not changed, where did they go wrong?...

The RENESIS 1 had a new MOP set up (you know that), but for the first time no centre Apex Seal Oil Lube, Mazda thought Oil would makes it's way to the middle, by the time after all the "PCM Flashes" the damage was done, once you have an Apex Seal that is wearing inconstantly it won't rectify itself no matter what you do....upart from a rebuild.

And sorry if you do not pre-mix this issue will happen again, and again.
Because Mazda have not and can't rectify this defect just give you an engine of the same design. Apart from giving you a new car..

Have they fixed it in Series II..?? time will tell, I have two concerns, one Mazda are still being a little conservative with how much oil they are now injecting into the 6 nozzles.
The "Public" think it is wrong to add oil remember..
IMO it is the best lube system they have done to date..but..
And two, the side seals, with the 'loose' Side Seals moving until hot, over time this is cutting/wearing the side seal spring with a shorter engine life.

Why, again it is really all guess work, I sometimes wonder why Mazda even persist with this engine myself because from and "industry" point of view it has held them back both financially and in the market, Mazda should be a much larger company than they are today.

As we know they developed the Renesis on a shoe string budget and running out of development time....look what it has cost them YET AGAIN!.

The RX-8 has not made Mazda any money, they are loosing a bucket load...again.

They are very fortunate that this so called Global Financial Crisis or Recession (Australia never went into BTW) appears over very quickly and sales are improving.

Mazda had a new generation of Rotary enthusiast with half of them now being burnt...yet again.

A lot of again's in there..

 

Don't need it..all it's Oil is Fully Filtered before it goes into the engine!

Interesting to see your test results....Doctor...

 

BTW, I am really surprised no one has yet noticed ANYthing that is different in Pics on this page and previous...and it is quite significant...and for a change I am not telling you...

You must be FED UP with me by now..

 

Are you talking about the bearing oiling holes?

 

Play the Ta Dar Music... Yes, the above pics are of the 0820-10-502B also used in the 4 port RX-8 AT (Low Power)...where the 6 porters (High power) use the same bearing with more oiling holes and a bearing locking pin.

BTW.. Mazda still make the 4 ports in S2... not for USA or Oz...I think JDM only now.

 

Should I find it strange that the high power version utilizes significantly more oiling holes just because of higher RPM and power? Does the e-shaft see significantly more heat in the high output version over the 4-port? Unless there is a significant difference in manufacturing cost, I don't see why both versions wouldn't just use the same bearings.

 

Got into an interesting email discussion with a Royal Purple Tech Services guy today. I initially emailed them about the use of their TCW III product as a pre-mix, and it turned out the tech is a rotary-head, and we got into a discussion about oil choices & rotaries.

He had a RX3 that he campaigned in SCCA GT3 for two years. 250 hp normally aspirated 12A. Used TCW III as the premix (no MOP) and XPR 5w30 as the oil. I asked about his reasoning for 5w30, and he said that he was running 140 psi of pressure from a dry-sump arrangement and didn’t think he had the power to push 20w50!

In general, he recommended RP 10w40 or 15w40 as a “conservative” choice for street use in the Renesis. Apparently, both are API CI-4 rated and contain 1300 ppm of ZDDP (which is much higher than the ~800 ppm of typical 5w20 or 5w30). The RP XPR 5w30 has 2000 ppm of ZDDP. He made a similar point that others have before – it’s not the viscosity so much as what’s in the oil.

Anyway, just wanted to pass this on. Pretty much in line with what has been said here before.

 

Wow, I'm shocked that you were able to get any information about RP's formulation. Anyone I've seen who has emailed RP or even called their tech line could get any information from them. ZDDP content has been one major question and RP has said literally that they don't disclose numbers because people get hung up on them and it doesn't tell the whole story.

So, that information is pretty good! The one thing to keep in mind is the API CI-4 rating is a diesel oil rating. The XPR is RP's racing series oil which, while stated to be "safe" for street motors, may have a shorter change interval than their normal oil line.

 

Good info on the 2 stroke. Have to see if I can find it. Flash are you premixing your gas as well as running the SOHN?

 

Interesting, guess I got lucky.

He did say that the 5w30 or 5w40 would be a good choice if running XPR, which, as you say, is their race oil (and expensive!) I do wonder about the high ZDDP content & cats, though. He said he used to run XPR in his 94 R2 FD on the street.

 

there is less phos/zinc in diesel oil than ever before. I believe a lot of lotus owners use moble 1 diesel. No cat problems that i am aware off.
OD

 

Strange??, no, that is Mazda for you...

They use a now 40 y-old Stationary Gear Bearing 0820-10-502B (first from the 1969 10A Mazda R100), in all Rotaries up until the FD RX-7 (1992), when the NF01-10-E04 Multi Oil Holed Bearing was born, but Mazda only used these in their 6 port RX-8's, the 4 Ports continued to have the 0820-10-502B Stationary Gear Bearings (two), in Series 1 RX-8's.

WHY?, who knows, really one would think the later Bearing would be far better as it allows more oil faster around the E-shaft Journals. Keep in mind there are NO Oil Pressure or Oil Pump changes between a 4 and 6 port engines.

Having said that on the Series 2 4 ports they now use all the same bearings, the ones from the 6 port RX-8 and FD RX-7.

I also have the inside info that MNAO re-man plant are ONLY using the Higher RPM or 6 port Stationary Gear Bearings, even for the S1 Automatics (4 port).

And yes, the 4 port is a lower HP - RPM rated Rotary Engine.

 

Care to comment?

https://www.rx8club.com/series-i-tech-garage-22/oil-product-data-sheets-186187/

 

1300 ppm ZDDP? thats quite a lot

and DANG ! 2K ppm ZDDP for the XPR line ????

wow ... thats pretty good ....

HMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM .... what should I do what should I do ...

Notice that most Royal Purple oil are NOT SM grade. Only 0w40 and 5w40 are SM. I mean I have no problem with that, cuz I always think SM grade is a "HUGE" step back from SL, IMO they create SM grade for tree huggers.

20w50 is SJ grade, oh yeah baby.