well, i think these guys are running FD's, and they don't have to worry about COOOOOOOLD (!!!) start-ups like you do, and we all know about the heat thing once those 13BREW's get their legs all stretched out... just a precaution in an engine which runs more than hot enough for it.

 

This is part of what I was getting at in referring to a special 'rotary formulated' oil. Something that offers the extreme temperature protection of synthetic, but is also designed to burn clean in the combustion chambers.

I'm far from an expert on this but I imagine the rotary also uses slightly different metals that might require slightly different lubrication properties.

 

Maybe we should E-mail some Oil producers like Castrol, Exxon, Mobil,... in name of the RX-8 and/or RX-7 Forum and ask their solution of this neverending "Rotary Engine Oil Quest"??

 

I guess you've never owned a rotarty, eh? The owner's manual (I'm not even talkin' about the shop manual) of my '86 NA sed that depending on conditions, burning as much as 1 qt. in 500 miles is within spec limits. My personal experience was something like 1 qt. in 1k-3k, approximately.

---jps

 

I don't think many people have owned a "rotarty".. Maybe a rotary :D

 

Hey Hey Hey... Do you want me to spend all sorts of time spell-checking and re-spell-checking my notes here, or would you rather I'd rip through this response and go spend my time pulling pictures from Boowana instead?

I didn't think so... :p

---jps

 

Of all the words you spelled wrong though....

*shame shame* :D

 

Here's your special "rotary formulated" oil - at a mere $107 per 4 liter can.

 

nope. hope to call a black FC my own someday (i thought i kept repeating that too often, myself ).

anyhoo, yeah, i did remember the number wrong... i musta just added a zero on there in my head... whatev, it's all kinds 'o' good now. thanks.

as for jdachik's rebottled "Mazdaspeed" brand oil, i wonder what it really was...???

 

As the proud owner a 94 FD RX-7, I have used nothing but synthetics since the engine broke in. I remember the skepticism I possessed when I first tried the mobil 1 15-50, but it was all vanquished after starting the engine. The car idled smoother, and the engine seemed to just run smother all around. With the RPM the turbos reach in the car, I would worry about shear and brakdown in the oil, so synth is safer, and the ash contents have come down to negligable levels in some brands.

Another thing that made me decide to go with synth was that I NEVER saw any posts on the forum about anyone having actual damage occur because of synth oils. after running synth for 20,000 miles on my FD, the engine still purs like new.

Really the ONLY concern of using synthetic oils is the ash content. if you want the benifits of synth oil, but don't want the ash risks, disconnect the OMP and put a premix in the gas. or there is some comapny that sells an OMP adapter to have it inject 2-stroke oil for a seperate resivior instead of going from the oil pan.

 

If you research the issue with Rotaries and Synth, it was the Ash content from the engine burning the oil. Actually when originally tested there was only one Synth that caused an issue but since Mazda (small and poor at the time) didn't want to have to deal with a potential lawsuit they just made a blanket statement to not use Synth oils. And as for Synth being better lubricating, I have personally tested several oils, and additives with a bearing tester and surprisingly Castrol GTX was the best lube of all of them. Of course that was just a short 5 minute/per oil test, but it was enough to convince me. If you want I can get the number about PSI of pressure to the bearing for different oils, I for sure have the Castrol.

 

It is ok to run Synths in a rotary, but you MUST change the oil at the same intervals as dyno. Must! Must! Must! Do not think you can go longer between changes just because you are running synth. Change it at 3000 or before. Can I stress that any more?!

With that said, I run a Dyno oil, Castrol 20w50 in my FD and TurboII REPU, as the only synth I would run is Royal Purple, and at $5 a quart, I cannot justify the cost, when I can get the dyno juice for $0.99/qt at Walmart.

 

You bring up a good point Dan, because rotaries burn oil

Can't forget that now!

 

An additional point, maybe not as obvoius, but gas does get into the oil... with turbo rotarys in particular. If your oil gets soaked with gas, the combustion chamber will not seal, your compression will go way down, and your rotary will not start. Just as flooding wipes away the oil coating, gas in the oil does the same.

it has yet to be determined if the RENESIS is as prone to flooding as the 13b N/A six port, but if you ever do flood your RX-8, change the oil right away.... no exceptions!

 

Wouldn't burning off oil cause some emissions problems for the RX-8? Would be pretty hard to meet the new lower emission standards if you're losing a quart of oil every 1000 miles.

Maybe Mazda has improved their design since the last rotary. If not, this engine sounds like it'll run like a 2-stroke. Since most companies that used 2-strokes in their products (Jet-skis mostly) are now moving to 4-strokes for better emissions, going the other way would definetly not be good.

 

welcome my friend. it sounds like you sorely need to bone-up on your rotary tech... PLEASE!! RELISH THIS TIME!! :D it is fantastic... ahhh, to feel that awe again... i'm sure i'll have a fat nostalgic shock when i buy my first wankel

it is in fact very simliar to a 2 stroke engine, and yes, burning oil does pose a small concern with emissions, but the combustion cycle in the rotary is far, far more efficient than a 2-stroke piston engine, with a very long burn cycle... this, along with emissions catalysts makes this engine a very low emitter...

NOx was always good, and with side port exhausts, unburned HC emissions are coming well down too...

 

Per my research with a few Rotary developers in the US (Roger M., Jim D. & Rick E.). The rotary CAN use Synthetic oils in race trim. But, due to emission problems you cannot use it in productions vehicules... due to catalitic converters. Period.

 

The enigne will burn more oil if you drive it harder. The oil metering pump that injects oil into the combustion chambers pumps at different rates depending on how you drive the car. At full throttle all the time, you'll burn a lot.

Tons of people have been using synthetic oils in rotaries without any problems for some time. You can do oil analysis to get an idea of what intervals you should be using or what oil works best for your engine and operating conditions. Or you can just go along with what the manual or other owners recommend, which is also a reasonable choice, in my opinion.

Frequent oil changes are recommended for rotaries. I wonder if extended intervals could be used with synthetic in the RX-8. Oil analysis could help make that determination. On the turbo cars, the oil is pretty beat after 3000 miles, so I don't even g that long. Fuel dilution is a big factor.

I like synthetics. I use Royal Purple in my RX-7. The previous owner of my car used synthetic blends for a long time (based on the dealer history of service that I looked up) and it didn't seem to damage my cats.

I think the RX-8 rotors might have an extra oil control ring, which might reduce oil consumption or fuel dilution.

You need oil to lube the apex seals in the combustion chamber, so working to eliminate consumption is not a reasonable goal for an owner, in my opinion. Some folks with FDs have actually had the oil level go up or at least not drop. The verdict on that phenomenon was that they had lots of fuel dilution rather than no oil injection. If anything, you might want to pre-mix or electronically increase the amount of oil consumption to reduce combustion chamber wear. I think Mazda has to stike a balance between emissions and engine longevity when they design the system. As an owner, you might choose more longevity at the expense of more emissions if you decided to change that balance. However, I don't really feel compelled to change it.

-Max

 

BrianH- They already make many custom Rotary Oils that are sythetic now. I think RE Amenia(Bad spelling I know), Mazdaspeed (japan), Many rotary tuners make thier own oils. Royal Purple is my personal favorite.

Kyle Lancaster--Double Agent Salesman

 

Racing Beat recommends Royal Purple synthetic motor oil. They claim a modest INCREASE in horsepower.

 

...i think that's 'cause Racing Beat is a RP distributor/vendor, and would be in their best intrest to say so regardless of whether it's true or not for everyone.

of course, RP is a great oil, but i'm uncertain if it would be well suited to RENESIS use yet.

 

Correct oil to use is a mineral oil from Mazda 5W-30 designed for the rotary.

Ask your Mazda Delaer they should have it.

If not we do here.

Run it in my 7

Best stuff by far !

 

HoW much does it cost? just wondering...

 

it would be around $20 us

for 4 litres

 

Do you know what qualities in this oil make it "best for rotaries"?