Smoker

From my understanding after this article:

http://www.evo.co.uk/driven/driven_story.php?id=32221

The Renesis Rotor Tips Seals needs to be "replaced" after 150,000 miles. Anyone knows what is going to happen as the Rotor Tip slowly wears out ? I mean would the engine start losing tonnes of power or would the engine just stop working all together as these seals gives way ?

Also, what would the process be to "replaced" these seals ? New Rotors ? Engine Rebuild ?

Any help on this would be greatly appreciated. Thanks

wakeech

having an apex seal fail is kinda like having a piston ring fail: you need a rebuild, but if the failure is really really bad (like it splinters and scores the block), you're royally f*cked...

that number is the "theoretical" minimum life: there are lots of guys out there with like 200K miles on first and second generation RX-7's (the non-turbo kind) that have been taken care of (like they just didn't miss any oil changes, and kept 'er topped up), and still make goodish compression.
of course, if you neglect it, as with any engine, you'll ruin it quite quickly.

Hercules

I don't think it would be a big deal to replace the seals.. take the engine out of the bay, open it up, remove the two rotors and replace them.

If you look at the video (it's here somewhere) where the techs are assembling the engine... you'll realize how easy it is.

wakeech

the labour isn't in the replacement of the seals, but all of the incumbent work that comes along with rebuilding the engine: as a rule, if you're gonna take it apart, you don't do it for one reason... you'd (most probably) want to "upgrade" as much as you could, get things resurfaced, etc etc...

although yes, it would take maybe an hour, hour and a half of labour (of a skilled wankel builder) to unbolt, then rebuild the whole engine, as long as nothing was seriously out of whack and you just wanted to replace the slidie-bits...

Superfan

My second gen NA got upto 210,000 before one of the rear apex seals went south.

justinm2

The acutal replacing of the seals is quite easy. It's the cleaning that is very time consuming. you have to clean out all the carbon deposits, and other trash from every crevice in the rotor and rotor housing. It take's forever. Once its clean reassembling the engine only takes a short time. Just make sure while you have the engine apart replace all the other seals, not just the apex seals, and you also replace all the springs. ( we found out about the springs the hard way, we built a couple of engines, and just replaced seals, 10k later, we were rebuilding the engines again) As far as the seals wearing out at 150k, I find that hard to believe. My 85 gsl-se has 320k on the engine, it has never been apart, and still makes great compression. It hasn't been babied either, I typically don't shift until well into redline. Just change the oil, and don't let it over heat.

Hercules

These NA mileage numbers are very reassuring

JTek_55

Um, dumb question here... what does "topped up" mean?

Smoker

meaning topping off the Oil Level to prevent the engine from running out of oil.

zoom44

rotaries apex seals are lubed with oil. some of this oil burns off through the combustion cycle, therefore it is neccessary to keep an eye on your oil level and keep it filled up to the proper level.

rxeightr

Somewhere I read oil consumption is reduced by 50% in the RENESIS over the previous rotaries.

So, any guess how many miles you could go before you need to put a quart in? And can you wait until it is a quart low before adding any?

Hercules

Just my advice, but check the oil on every other gas fillup. If it's low, dump whatever you need in. Keep a quart in the trunk at ALL times.

justinm2

the older ones with the mechanical linkage oil metering typically got about 1000 miles to a quart of oil, the 2nd gen cars went to an electrically controlled oil metering system that cut consumption by reducing oil at low rpm's to help emissions. the downside to that was people would baby the cars around town and never wind the engine up to the point it was injecting enough oil to lubricate the seals and were burning up engines, while the guys that were beating the **** out of them were getting multiple hundred thousand miles out of them. I'm not sure what the oil consumption was on the 3rd gen which is what i'm assuming they are basing it on.

wakeech

my favourite quote from justinm2's post on FC3Ses...

:D so elloquant, so beautiful, so very right. :D

rotory_it_up

What material are the apex seals?

Also, does anyone know the oil capacity?
If it is around four quarts as most small displacement cars are, then I don't see any problem with letting it go to a quart low before adding. Of course, if you really ripped the sh*t out of it all the time(as I will), then it is probably a good idea to check it pretty often. The harder you drive, the more oil will get burned.

PsYcHo_Pilot

i'm not shure about when they were first made, the 3 piece apex seal seems a rather good option. As we all should know increasing combustion pressures by turbocharging and intercooling will royally screw your seals a hell of allot faster than normal. check this out, a 3 piece apex seal design.

You'll need Adobe Acrobat reader, scroll down to pg15 on the scroller, or the page number on the sheet pg271 if you want to skip the mathematical design of the engine. (quite interesting) It is not the Renisis, but the Wankel.

ENJOY !
3 piece Apex seal

:D

Buger

Nice paper that I've had bookmarked for awhile. :D 3 piece apex seals have been stock for quite some time. The caption of the diagram says it was reprinted from a 1987 SAE aticle.

I think the same diagram was somewhere on the Asmic site too.