9krpmrx8

iTrader: (46)

Thanks, let me know where. But unless someone drives a **** ton, based on your math running synthetic would only cost about $1,000.00 over 2 years @ the average 15,000 miles a year.

Lowest tier you say? Do tell. I anxiously await your explanation.

Karack

i don't drive a whole lot and if i priced out my oil changes it would cost about what you figure in oil for royal purple which is what the OP of this thread is pushing on people.

so even if it was 4 years to save $2k in oil that's still like paying for an engine every 4 years in oil alone on my driving mileage.

will synthetics save me 4 years of life on an engine at 15k miles per year(60,000 miles)of overall important wear? i'd like to see that actually proven. i think i'd rather have new side and apex seals every 4 years versus a little additional copper showing on the less significant rotating bearing surfaces.

shadycrew31

iTrader: (6)

This thread is completely worthless, can we please lock it down before more "experts" chime in?

Karack

don't like it? don't read it.

ASH8

AWK, Mazda had NO choice but to use side exhaust porting, peripheral exhaust porting will never ever be seen again in a gasoline rotary, for obvious reasons.

9krpmrx8

iTrader: (46)

^ True.

Karack

if that reason being PP exhaust being too "dirty" emissions wise i am going to wave the BS flag around.

paimon.soror

iTrader: (15)

not because it is "dirty" .. because no one wants to invest in "cleaning it up"

shadycrew31

iTrader: (6)

It's not me I am worried about, its everyone else.... This thread is very confusing and will cause more harm than good.

The problem with rotaries is every engine is different, has different wear and different owners.

You cannot establish a baseline of what product to use or method to try because there is not enough data for a baseline. Too many variables and opinions mixed up with "expert" advice gives you a recipe for disaster.

13B's are completely different from the Renesis engines, the only similarity is that they are both rotor powered. (Seals are different, oil galleries are differnt, rotor weight is different, bearing tolerance is different, omp system is differnt, housings and irons are different).

One thing everyone has failed to point out is that the E-shaft rides on the bearings, if they start to wear abnormally the e shaft will be out of balance ever so slightly. If you don't believe me that's fine I really could care less. As the e-shaft wobbles the rotors are effected and beginning to show premature seal wear. Now the springs and seals account for this slightly out of spec wobble, however over time this begins to wear down the side seals causing them to go out of spec and lose compression.

Thats my theory at least and its just as good as all the rubbish I've read in here.

RIWWP

iTrader: (2)

Given the technology they had access too during the years of development, plus Ford's hand in everything Mazda did, yes, I believe that PP exhaust simply was not possible to meet at that time.

I feel that I'd have blinders on if I believed that it simply was not possible at all to be able to design a rotary engine that met emissions standards with PP.

I also don't believe that the only two port options are the historical peripheral and the current side port. There isn't "another surface" to use, so ports will always be on one or the other (or both). But technology advances forward and Mazda tries some crazy stuff ... that sometimes actually works.

At the risk of adding moving parts, I could even see an "auxiliary" exhaust port that opens similar to the current intake valving, to improve high RPM and/or high load flow. Troublesome? Sure. But possible. Mazda sees the word "impossible" as a challenge to overcome.

RIWWP

iTrader: (2)

9k referenced that earlier as well. If I recall, most of the bearing wear typically showed up at specific positions? Balance would certainly play a role in that.

ASH8

Bearings and tolerances are identical to the FD 13B.

What IS different are higher RPM in Renny and Oil Grade...and I agree sustained higher RPM could be the reason for excessive wear in bearings, not that this has never been seen before in RX-'s as it has, just appears to me more so IMO.

ASH8

BTW: Just remember IF the 16X ever does see production it will have Side Exhaust Porting.

You also have to remember that Mazda (JAPAN) designs/makes engines to meet ALL world markets, not just the USA.

Owners in Europe are being taxed by the amount of CO2 from the tail pipe, a PP rotary could never get below 200g KM, even with latest CATS or worse costly thermal reactors.

If a car can not get under 120g KM, soon to be 100g KM, (S2 RX-8 180 g KM) it is unsaleable in Europe and almost everywhere, except USA for the time being and Mazda are not going to make an all new car just for the USA which might sell < 60,000 units year, IF they are lucky.

China could be the only hope for a larger market share RX-, but the RX-8 was a dismal failure there.

Time we got a little more real here.

shadycrew31

iTrader: (6)

There are 10 different main bearings with different tolerances for the 6 port and 1 for the auto, the auto rotors and 6 port rotors also have different bearings. The FD shares these same 10, FC has only one bearing.

Rotors bearings are complete different as well as the weight of the rotating assembly.

Most Renesis engines were assembled with Yellow bearings, but not all....

So that's 10 different tolerances you can play with. I'm sure those tolerances don't matter on an engine assembly though.

RIWWP

iTrader: (2)

I'm realistic Ash. I just perhaps give more consideration to the crazy Mazda engineers that are willing to try anything (like 14:1 CR on a piston engine on pump gas). What may be thought as not possible today very well might be possible tomorrow.

ASH8

OMG..Grasshopper..

Rotaries that come out of the factory NEW, all use STANDARD size Bearings.

Which is what I am talking about, NOT after the fact.

Yes, Mazda sells oversized Bearings for those who want to repair (@ rebuild), but no one really uses them, why?, most E-Shafts which need OS Bearings are gone, so you replace with new E-Shaft and Standard Bearings.

I am talking STANDARD bearings, not Over Sized, Used After the fact.

ALL NEW Rotaries out of the Factory use Standard Sizes, except pre-cut Side Seals.

ASH8

...

Brettus

iTrader: (2)

Can always rely on this thread to liven things up when there is stuff all else going on .....

nycgps

iTrader: (1)

The the record, FD3S's stock redline is already @ 8K with much higher power. stock balancing is not perfect but it's not that bad. but they are crazy to have such low oil pressure.

the MAIN REASON Mazda went SP instead of PP is because it reduces crap by 50%, it has been well documented by Mazda.

The only way I can possibly think of is they have to use ultra high compression rotors, at least 12:1. but 2mm seal gonna get owned easy. if they switch back to 3mm seal then maybe. but idle gonna suck at low rpm ...

a lot of people in China love Rotary, but market demand is low because the gas quality in China is like ... crap. You get denotation even you are on stock tune using their "premium" gas on RX-8 ... well if you are lucky or you know that station has "Quality gas" not mud water then maybe ...

and most of their "3S" shop (China's term for Authorized dealer) doesn't even know how to fix Rotary Engines ...

too bad, as far as I know only Japan has 14:1 CR, rest of the world gets only 13.5 to 13:1.

shadycrew31

iTrader: (6)

I'm not going to argue with you... Theres no such thing as a standard bearing for the 6 port. There's what they use often but its certainly not standard.

Since you don't know this I nightly doubt reman facilities know this.

Therefore its quite possible that a reman could have two completely different tolerance bearings and no one would ever know.

Again the Auto is the only engine with a one size fits all bearing.

rotarygod

A compression ratio higher than 11:1 on a 13B based rotor geometry is the highest you can go before losing power but 11:1 doesn't really make anymore power than 10:1. It flat lines. The new 16X geometry however may change that.

Karack

i'm not following. how exactly does a renesis rotating assembly differ from earlier rotary engines?

this total BS that the renesis is some magical engine versus earlier rotary engines should be put to a stop. the tolerances are the same for the rotating assembly.

yes the engines operate differently in how they draw in and evacuate the combustion events but aside from that they are nearly IDENTICAL to early engines. the difference is that they run thinner weight oil recommended to aid in lowering emissions due to drag. this in turn as well as the higher revving characteristics of the renesis causes the bearing to show more wear than the earlier engines.

as i've also already mentioned elsewhere the bearing wear is almost always attributed to accessory drive belts and the amount of tension placed on them, along with oil viscosity. place an engine on a stand, put a pipe on the end of the e-shaft and pry up on it and that is what your belts are doing to the e-shaft, side loading it, which is also why the wear is localized.

Paco664

so basically you are saying with rotaries belt tension is as important or more important than oil viscosity for engine longevity??


interesting.... and makes sense...

shadycrew31

iTrader: (6)

The oil gallery's on the renesis rotors are larger than previous engines, the rotors are lighter and have a higher compression ratio, the Eshaft is not heat treated and doesn't cost $400+, the entire weight of the rotating assembly is different.

The bearing clearance/designs are completely different than 13B/13Bt engines.

Hypothetical example, If a reman facility had a shipment of blue main bearings and found several engines with front bearings out of spec. However the rears were Yellow from the factory and were in spec. That means you now have two completely different bearing clearances in the front and rear causing an unbalanced rotation.

There are tons of builders out there who order a main bearings without measuring or even taking into consideration using the proper bearing. If it had a blue before it needs a blue again not a yellow.

The seal tolerances are not the same as previous engines the side seal location, shape and strength changes tremendously. Not that any of that matters for the conversation at hand.

As a side note I've seen bearing wear on 10W30 engines, using Synthetic and dino oil.


Second sidenote: I am pretty sure I am the only person in this thread who has seen more than one engine taken apart and has rebuilt more than one engine and has actually worked on this car.

I am not trying to puff my chest I am just giving you some real world info about the engine, not from a book, not form your buddies BFF whos been building engines for 300 years. from me first hand experience.

Iluvrevs

To correct an innacuracy the FTIR test wlll distinguish between oil base stocks mineral, group IV, or group V. But the equipment to do this is so expensive only the majors like Mobil have ready access to it. We common people can pay for this test but its around 400$ last I remember and its highly unlikely an OEM would spring for it to defend a warranty I think. The test essentially tests gasses given off by the oil at high temps over a certain time frame but its been awhile and I don't recall the specifics. Not that any of this will make your engine or any engine last longer though.