Engine destruction caused by bearing failure.
 

Hope this is the correct section, this is copied over from the rx8OC (UK) so the names might not make sense but still this is what I found on my latest teardown :(. BTW engine had 53K on it and died while the owner was driving it.

Ok so many know I recently purchased Waveydavey's RX8 which was thought to have a dead rear stationary gear. When it arrived I turned the engine over for about 2 seconds and quickly realised it was a bit more than that. Well I finished stripping the engine today and this is what I found.

The first indication something big had gone wrong was when I looked in the oil pan and found chunks of copper. All that glaze is copper.
http://www.rotaryrebuild.net/rebuild...y/CIMG2261.JPG
http://www.rotaryrebuild.net/rebuild...y/CIMG2262.JPG

Its in the front cover as well
http://www.rotaryrebuild.net/rebuild...y/CIMG2264.JPG

When I took the rear cover off I thought I found the problem. The bearing is junk but the gear does not look too bad.
http://www.rotaryrebuild.net/rebuild...y/CIMG2265.JPG
These bits sound be in the bearing not round the e-shaft.
http://www.rotaryrebuild.net/rebuild...y/CIMG2266.JPG

I gave a quick looks and thought it does not look to bad.
http://www.rotaryrebuild.net/rebuild...y/CIMG2267.JPG

O but wait no its not, I then got the the front bearing.
http://www.rotaryrebuild.net/rebuild...y/CIMG2271.JPG
It has slipped and cut the bearing in two. The whole stationary gear is junk.
http://www.rotaryrebuild.net/rebuild...y/CIMG2272.JPG

O and this is what its done to the e-shaft.
http://www.rotaryrebuild.net/rebuild...y/CIMG2273.JPG
Yep that's junk as well.
http://www.rotaryrebuild.net/rebuild...y/CIMG2274.JPG

So what I thought was all the damage, how wrong I was.
http://www.rotaryrebuild.net/rebuild...y/CIMG2275.JPG

Just for fun I tried to remove the bearing from them, the rear came out fine and the gear looks fine, the front did not, the bearing just folded over itself and my 12ton press could not get it out.
http://www.rotaryrebuild.net/rebuild...y/CIMG2287.JPG
http://www.rotaryrebuild.net/rebuild...y/CIMG2289.JPG

I then looked at the side housings, the rear and rear side of the intermediate were fine but the front side O dear.
I struggled to catch them on camera but here we go.
Where the bits of bearing have been dragged round.
http://www.rotaryrebuild.net/rebuild...y/CIMG2270.JPG
http://www.rotaryrebuild.net/rebuild...y/CIMG2269.JPG
http://www.rotaryrebuild.net/rebuild...y/CIMG2276.JPG
And more
http://www.rotaryrebuild.net/rebuild...y/CIMG2277.JPG

O but wait there is more, the front rotor has scoring as well.
http://www.rotaryrebuild.net/rebuild...y/CIMG2278.JPG
http://www.rotaryrebuild.net/rebuild...y/CIMG2279.JPG
http://www.rotaryrebuild.net/rebuild...y/CIMG2280.JPG
The front rotor may be reusable in a test or development engine if all the groves have not been damaged, the rear looks fine.
The rotor bearings are junk as well, you can see all the copper soaked oil.
http://www.rotaryrebuild.net/rebuild...y/CIMG2282.JPG
Cleaned you can see the damage.
http://www.rotaryrebuild.net/rebuild...y/CIMG2283.JPG

Copper covered.
http://www.rotaryrebuild.net/rebuild...y/CIMG2284.JPG
and again bearing is junk.
http://www.rotaryrebuild.net/rebuild...y/CIMG2285.JPG

So in summary, all bearings are junk, one stationary gear is junk and one is questionable. The E-shaft is junk, 2 side housings are junk at the moment but I might have a practice with them and hand lap, then use them in a dev engine. One rotor could be junk but not sure yet. What's worse is I am going to have to drain all the oil out the oil coolers and flush the system through to make sure there is no more copper when the new engine goes in. Glad I brought Keljon's spare engine, now just need to get it.

Good writeup!

Could you describe the driving conditions, mods, maintenance, and motor oil used?

Repost :)

The oil was hardly ever changed in this engine. IIRC, it was only changed a couple of times and usually was just topped off. There is a thread about it on Rotary Heaven.

Basically the last guy only had for about 6 months and when he got it the damage was already done, shame as it seemed he tried to look after it during his short ownership.

I have built the new engine to go in it but want to clean out the oil pipes and coolers before I put it in just encase any of that copper oil has got round it.

Good idea, I would definitely clean everything out.

Another problem is they likely didn't change the oil filter......so after it plugged up the bypass opened and everything just kept going round and round till it ate the bearings

This isn't a rotary specific problem though....any engine with no/dirty oil will look like that very quickly :)

And the engine didn't die because of bearing failure...more failure of the idiot who owned it :)

something I did find it trying to clean off the copper filled oil is almost impossible without using solvent. I have a spare set of oil coolers so if I find any of that copper oil in there I will just swap them rather than trying to clean and then blast the oil cooler lines though with solvent and leave them to dry for a day. I have not reused any of that engine in the new one.

Agree with all the posts, this engine looks like Oil and or Filter was never or hardy ever been renewed, even oil starvation/low engine oil, excessively hot and the dark oil marks also shows high engine temps, and possibly, possibly Alternator, Water Pump and or Compressor Belts may have been overtightened as some evidence that excessive bearing damage can be attributed to over tightened Belts....something I guess now is hard to check or prove with this engine.

E-shaft has had it, could get away with resurface of Iron's?, depending how deep scouring is.

But yeah, poor maintenance looks like one of the reasons.

Remeber tere was a guy a while ago said he never changed his oil and got like 100k or more miles and he brag about it? Like i said he was just fucking lucky his engine could have been a perfect one and would probably last 200 300k if he actually change his oil

This guy is not so lucky, but i would say the previous owner totally fuck it up, people like that should have their licenses revoked and banned from driving for life

What a waste.

I washed out the oil coolers and pipes today, there was very little copper oil in them so they should be good to go now, then the heavens opened so had to stop there :(

Cool, I would definitely do oil changes every 500 miles using an inexpensive 10W-40 for the first 2,000 miles just to be safe.

It really amazes me that in this day and age people still do not know or care to change their oil. WTF is wrong with these people!!!!

why not? consider how my friend who has a family owned sieena, drove it when it had like 4k on odo, then drove it again at 24 k and engine ligbt is on my friend was like toyota sucks the car is going slower and noisy as shit with so little miles. then when i ask when was the last time the car had oil change? cuz the engine sounds like its having a hard time moving, then he was like huh? cmini van needs oil change?

when i took the car to have the oil change, it came out almost like sludge the dude at the shop was likewtf happen to the car never seen anything like that before. after told him what kind of treatment the car has recieved first thing he said was holy shit. after the oil change and 10 miles later, the engine worked so much better i think the new oil cleaned the sludve up and it starts working again. but they still sold it shortly after cuz they know they fucked it up.

now they do oil changes exactly the way the manufacture wants it. a honda oddessy and anacura rdx.

he should have used 20w-50! :-)

Ha, not even 20w-50 would have saved a motor with that kind of damage.

The issue is without filtering the actual pieces of material will grind down the bearings as the film strength gets less and less over the life of the oil. At some point the pieces would have gotten big enough they would grind anything it came into contact with.

Common oil to use in the UK is 10w40 or some 10w30, luckily the new owner had replaced the oil filter so that had removed some of it, but the oil pump is a mess, it looks like is been used a grinder lol.

Yeah, problem is, they tend to use the cheapest nastiest mineral oil they can find in a supermarket...

The oil should be blacker even with the copper, so it's possible that coolant had already leaked into the oil and the ethylene glycol scored the bearing.

I had a RX3 with water jacket failure on the first engine, and the second engine apex seal damage from not fixing the cooling problem from the anti leak additives I used to seal the first (driving at 7k rpm redline for a few minutes on hwy).

This engine is easier to lube than piston engines in that you can run almost any oil, and the bearings usually run long enough that the seals are gone before.

That is pretty much exactly what happened when my engine blew, though not as severe. Mine happened in 6000 miles, and In that 6000 miles I had 3 oil changes. Turned out mazda remans aren't always put together right...

Now back up and running with its new mild street port :D

Good to hear :)