Oil related failure in the Renesis rotary engine

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Originally Posted By: SilverC6

The gas mileage issue is the real deal killer.


And it's really too bad. The RX-8 seems like a really cool car and I'd be game for having a quirky, unique engine. Especially one that not only *will* rev to 9k RPM, but one in which you in good conscience *need* to rev to 9k RPM to keep it in good shape!

But I couldn't justify getting a 230 HP RX-8 when the 370z is out there with 330 HP and gets better gas mileage.
 
I have been getting a solid 20 mpg this winter in Alberta doing city driving. Could be better but not as bad as people make it out to be.

Show me another rwd car that can fit 4 people, handles on rails, revs to 9000 rpm, and comes with a 8 year/160k engine core warranty.
 
I thought the thing that hurt RX-8 sales was that in order to have fun, the engine would need to be revved hard, much like driving certain VTEC Hondas.

I often compared the RX-8 to the Honda S2000, because they both have engine built for high RPM almost exclusively, they have similar weights, similar body sizes, and suspensions built with cornering as priority #1.

Mazda RX-7s had many fans because the rotary was turbocharged, and with the right turbocharging, low end torque was raised, especially in the ones with sequential twin turbos.

What would a Renesis with sequential twin turbos be like?

Also, maybe the Renesis of the future would have direct fuel injection to help performance, smog, and fuel efficiency.

One thing always amazed me about the RX-7. Some of them lasted for ages, while filled with conventional, and that conventional had to lube the turbocharger, what a difficult task for conventional oil.
 
Originally Posted By: rationull
But I couldn't justify getting a 230 HP RX-8 when the 370z is out there with 330 HP and gets better gas mileage.


Pistons are good
 
Originally Posted By: digitalSniperX1
Early model RX-8 engines (Renesis) (mainly 2004-2005) had oil metering pump issues (low quantity) and quality control issues, esp with clearances in the side seals.

They are now warranted for 100,000 miles/8 years.

There is talk of a larger displacement two rotor engine (1.6L) in the works that will increase torque and improve fuel economy.

Will it see the light of day with current RX-8 sales what they are (very, very low)....only time will tell.



Mazda was considering bringing back the old RX-7 moniker and increasing the horsepower and displacement for a new Rotary. And possibly allowing for a turbocharger on some models as well for 2011 or 2012, but that's before their sales tanked and they put so much into the lackluster Mazda6...
 
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I used to own a '83 RX-7 with the 13B carbureted engine, and if I remember correctly, Mazda spec'd 20w50 for summer use. That's what I ran in mine...Typically Pennzoil yellow bottle. There was a company that remanufactured as well as modified and raced the Mazda rotary back then called Hayes Rotary Engineering. I don't know if they're still in business or not, but I talked to one of the guys there, and he recommended Bardahl Engine Oil Supplement #1 added to each oil change. I'd never heard of such a product, and never saw it for sale in any parts store that I frequented.

I'm curious as to why the extremely thin oil, when back then quite the opposite was recommended. The only other vehicle that I ever remembering recommending 20w50 was my old '74 BMW 3.0S.
 
Originally Posted By: GT Mike
Bardahl Engine Oil Supplement #1 added to each oil change. I'd never heard of such a product, and never saw it for sale in any parts store that I frequented.


They sell Bardahl #1 and #2 at many stores in Canada. The #1 I believe is some type of polar molecule friction modifier, that would be my guess, it smells very strongly of electric motor brush dust, but it's transparent and colourless. Bardahl #2 is like their last resort additive and is just some super thick additive like Lucas or NO-SMOKE.
 
I believe that Pennzoil High Mileage may be just the right prescription for the RX8.

The oil has a little higher viscosity than standard YBP.

It also has some seal conditioners that may help the Renesis last longer.

I picked some up at Walmart back when it was $12/5 qt. jug.

With spring, the 5W-30 Pennzoil High Mileage is going in the Mazda.
 
Originally Posted By: Max_Wander
Originally Posted By: GT Mike
Bardahl Engine Oil Supplement #1 added to each oil change. I'd never heard of such a product, and never saw it for sale in any parts store that I frequented.


They sell Bardahl #1 and #2 at many stores in Canada. The #1 I believe is some type of polar molecule friction modifier, that would be my guess, it smells very strongly of electric motor brush dust, but it's transparent and colourless. Bardahl #2 is like their last resort additive and is just some super thick additive like Lucas or NO-SMOKE.


Smells like electrical transformers/equipment b/c it uses lead napthenate(sp) in it, and it is a 30-weight.
 
wow, yikes! i guess i shouldnt be smelling it then
27.gif


although it does reek, you could smell it across the room
 
http://en.wikipedia.org/wiki/Rotary_engine#Distinction_between_.22Rotary.22_and_.22Radial.22_engines
Rotary vs Radial engines

http://en.wikipedia.org/wiki/Wankel_engine
Wankel...
the "piston" is called a rotor
the "piston rings" would be the apex, side and corner seals
the "crank" is called an eccentric shaft
Wankel engines inject oil into the rotor housings to lube the apex and side seals. This oil gets burnt in the combustion process.

Don't oils with more additives (HDEO's, high mileage oils, 10W-40's, 20W-50's, etc) leave more abrasive ash deposits when they are burnt?
Do GrpIV or GrpV oils burn cleaner than GrpIII oils?

I worked at a (wankel) rotary shop and we always used conventional 5W-30 in the turbo RX-7's. iirc, that's what the manual says to use.
The early 1st gens and all the 2nd/3rd gens had oil coolers, and the R1 3rd gen get 2 coolers.

My buddy has been running 15W-40 HDEO in his 1981 12a but I've been wondering if a thick 5W-30 GrpIII synthetic or non-HDEO 5W-40 or 10W-40 would leave less deposits.
I've also been wondering if an upper cylinder lube could be used as a premix oil. And if that would burn cleaner than pre-mixing 2-stroke oil.
And if LC20 or FP60/FP+ could be used to lube and clean the rotor housings.
 
Good premix oil should not leave behind heavy deposits. I premix my 12A with Amsoil Saber Professional at a 100:1 ratio and my plugs come out very clean.
 
I will add to this as I actually have direct experience with this motor and in doing research I found this site (which is great I might add). I own a 2004 RX-8 GT with 96,000+ miles. My first engine died at 22k and saw nothing but Mobil 1 5W-20 with OIC of 3,000 miles and never more.

My second engine saw nothing but Castrol GTX 10W-30 (because the rotor heads swore heavier weight)with OIC of 3,000 miles and never more. My second engine had the updated PCM flash which increased the amount of oil being injected onto the rotors. This engine was redlined daily and only lasted to 73,000 miles (which was a lot longer than the first so I chalk it up to the PCM change and not the use of 10W-30).

My third engine now has 1500 miles on it and is only getting Castrol Syntec 0W-30 and I am premixing 5oz to 14 gallons of fuel. This engine also has the BHR ignition kit (Yukon Coils)

Mazda has covered both engines under the extended warranty and provide rental, etc. However, with the second motor I had to prove oil changes with receipts. There is no clear answer to this issue as there have been failures of engines running all kinds of engine oils. There are many factors and I have decided that heat is the most common denominator and I feel that oil temps and OIC are the key. With this motor I will be running an additional oil cooler, premixing, and doing "max oil out changes". If this engine fails prematurely then I am done with the rotary. I knew what I was getting into with this car but the "3 engine club" is pretty large and to be honest the average RX-8 owners have jump ship after the first engine replacement.

But for now I have a paid off car with a brand new engine that goes like stink on the road course.
 
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Just be glad this didn't happen to you!
2721027026_0216d3542f_o.jpg

It happened to me, and that was an EXPENSIVE repair!
 
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Man, you couldn't pay me to drive a car with a rotary. Every RX-7 deserves to have a LS1 under the hood.
grin2.gif


It's so sad that the V6-equipped Mazda 6 will absolutely wipe the floor with Mazda's flagship sports car, at least in a straight line. That V6 is tuned to run on 87; bump up the compression, maybe design a new intake manifold to shift the powerband up a little bit and design some slightly higher profile camshafts and voila! Instant 370z fighter. As it is now, though, I can't understand why anyone would ever want to own a RX-8.
 
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