How many miles? My brother's 70K on the original factory oil is still a benchmark.

Ken

 

Oh, just go ahead and tell us. Some say chunks of hard carbon can get broken off and cause damage elsewhere. On piston engines I've tried to avoid this by first doing an overnight piston soak to soften up the carbon and then using steam. Some people also say to disconnect the cat because of the high temps involved. Is there something else?

 

Steam cleaning is like the standard decarb procedure here since there aren't many good products available... never heard a single problem with the rx8 so i'm interested as well!

 

^^ you cant get Seafoam or ATF overhere?

 

You can get ATF but if the engine's still running fine then it's not worth all the hassle
Just some demineralized water and love (in the form of some lubricant )

 

The debate will continue until some real flow and wear data is produced on well maintained cars with one oil brand and viscosity in one temp zone.
My oil temps are barely breaking 75C on the highway in 9C ambient. It's going into hibernation in a week so this should be the worst of it.
We can't compare a Texas track car oil to a winter commuter oil can we? If we could there would be one right answer.
My Sohn adapter goes in this winter/spring. Then it's synthetic all the way for film strength and stability over temps.
RG, what do you plan to run with your sohn for Apex oil?

 

When I received my last motor I installed the SOHN, and BHR ignition during the first week or so. Then the BHR fuel pump soon after and converted to the Fluidyne single oil cooler. I have mainly ran a JASO FC Kawasaki 2 stroke in the SOHN reservoir for the first 10,000 miles but recently got a case of Idemitsu and I have been running that in the SOHN reservoir and the gas tank. I have also premixed the gas with the same since day one but I am now doing 1oz per gallon versus the 1/2oz per gallon I had been running only because I am running nitrous and a couple of other power adders. I am also running the COBB now and I will be adjusting the OMP rates.

For motor oil, I started with Castrol GC 0W-30 but ditched it after a couple of 1500 miles oil changes because I had it tested and the viscosity was not the best after only 1500 miles. I then ran Mobil1 0W-40 for a year or so before switching to Rotella T6 5W-40. I am thinking of actually switching back to the Mobil1 0W-40 just because.

 

i am not an expert but this is my experience so don't kill me.

i have 58k on my motor. from 26k miles i have been using cheap *** oil 5w40 and summers 10w40. i change my oil once a month and filter once every 2 months. i check my ignition coils every month (since that problem 100% of all rx8 owners have). the other problem associated with the 8's performance is not shared with 100% of the owners. i have fitted a wide band o2 to monitor the afr. my coils went bad at 29k and there was no noticeable difference in day to day drive other then lack of power on 3 and 4th gear pulls. my coils went bad again at 52k miles at which point i replaced and went turbo. my motor has not blown yet. i do not give my motor the opportunity to brake the oil down. 4k miles to an oil change? thats too much in my book. i use to have gt 30 on a subi and the turbo use to this the oil out like water. on the sti i use to use 10-40 with lucas oil stabilizer and still that use to happen. i also removed the cat before adding the turbo and that (for some reason) changed my cars oil consumption. i am not an expert but i have seen the 8's na and turbo engines opened and compared it to a 3rd gen 7s motor. there has been alot of corrections made to the 8 that were not there in the 7. the only advantage i see that the 7 has is the ablity of the user to program the car properly. i have been told by my tuner that one of the bad things about rotary is internal heat. changing the oil injector and fan characteristics can help (not cure). my belief is coils r the culprit of alot of issues, and oil changing habits must reflect the cars need. not all drivers r the same and not all cars run the same. remember our ecu learns from our driving habbits. once a month check up of these things would not hurt. oh and don't forget the fuel system.

ps. i am not saying the pictures and what that user has posted is not true. it is obvious that it is ( he has pictures lol.) but that is my experience.

 

Not sure what you see inside a Renesis that is so different than the RX-7 engines? Other than the side ports and the changes to the rotors..the rest of the parts are identical to most of the rotary engines since the whole thing started in the 70's

 

same here.

 

same..

I would like to know it what you do to "Check" your Ignition Coils every month?...what is your "check"?

 

And most 5-40 is at least a semi synthetic...so it can't be that bad

 

I'd swear Mazda hid a retard magnet in there somewhere ....

 

Ah I nearly forgot about this thread!

Once BHR gets my new motor built and the pains of all this nonsense are behind me I'll be sitting down with Ray and going over the specific numbers of my old motor and providing what I believe to be some conclusions (from my standpoint) regarding crank case oil use in the Renesis with an engine just over 109k miles.

Here's a preview: Aside from the damaged parts, everything else in the motor was within mazda's tolerance specifications and we had planned on reusing it all in the next build. This includes main bearings, oil pump, eshaft, as well as the rear housing and rear rotor. The rear rotor (undamaged) came out with very little carbon build up which tells me the 2-cycle injection is doing exactly what I had hoped.

The main bearing had some copper showing but we've attributed it to rotor wobble which seemed to have happened a bit over the course of the engine's life. Seeing as I ran a 9,500 RPM redline (and frequently hit it on the track due to gearing) I'm not surprised. However, the measurements with the bearing were all well within tolerance.

This motor has seen synthetic oil since after 6,000 miles and 20w-50 was used less than 25% of the motor's entire life.

Some point soon I'll gather the data and post pictures. Just something to chew on.

 

Interesting Flash. So how long did you run the SOHN and increased OMP rates? Do you attribute the bearing wear to frequently hitting the high red line? Also, Do you know how BHR balances the rotating assembly versus the way Mazda does it?