Renesis side seal discussion
#203
Go Texas Longhorns!
Cortc,
I'd rather you not drop off this as you appear to have some information and experience, no one is trying to slam you, but you have to admit its odd that you could have seen 5? Renesis engines apart. Giving us some idea of how you have seen these engines could explain why you did / didn't see this issue. I asked my service tech (who I've known for 8 years) what they do with the engines if there is an issue, and they send them back to Mazda.
I think we can keep this conversation civilized enough for all parties, as it is a rather important issue. RG and a few others were at SS and definitely found something interesting. These kinds of threads are why I love this web site, I get to learn the deep techincal details behind my ride.
I'd rather you not drop off this as you appear to have some information and experience, no one is trying to slam you, but you have to admit its odd that you could have seen 5? Renesis engines apart. Giving us some idea of how you have seen these engines could explain why you did / didn't see this issue. I asked my service tech (who I've known for 8 years) what they do with the engines if there is an issue, and they send them back to Mazda.
I think we can keep this conversation civilized enough for all parties, as it is a rather important issue. RG and a few others were at SS and definitely found something interesting. These kinds of threads are why I love this web site, I get to learn the deep techincal details behind my ride.
#206
Int-X 293WHP 242TQ :)
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Hasn't Cortc mentioned a number of times that he is with a dealer group that owns a large number of dealerships.
I was at my dealer for an oil change yesterday and asked the head rotary tech about the issue and he said he has seen two engines apart and neither had a side seal problem. He said both had over 10k miles.
I was at my dealer for an oil change yesterday and asked the head rotary tech about the issue and he said he has seen two engines apart and neither had a side seal problem. He said both had over 10k miles.
#208
mostly harmless
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![Thumbs up](https://www.rx8club.com/images/icons/icon14.gif)
Originally Posted by David Haskell
Hey if you guys look at the pictures I posted you can see that there is no way a side seal can catch on the secondary or auxilary port.
Dave
Dave
#210
Administrator
Originally Posted by cortc
Ok, well looks like some will see what they want and others will raise questions where none exist; part of the human condition I guess...
Not all engines that fail go back to Japan, only a few and just in the early build cycle. This is a mass produced engine and so far the failure rate has been well within the expected numbers. All of the manufactures including Porsche take back a few of the early problem engines it's actually part of the confirmation process... The Renesis is a very reliable engine compared to other high performance engines...
Rest assured what you have seen here is an isolated issue…
Gentlemen enjoy your search, will be un-subscribing to this one...![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
Not all engines that fail go back to Japan, only a few and just in the early build cycle. This is a mass produced engine and so far the failure rate has been well within the expected numbers. All of the manufactures including Porsche take back a few of the early problem engines it's actually part of the confirmation process... The Renesis is a very reliable engine compared to other high performance engines...
Rest assured what you have seen here is an isolated issue…
Gentlemen enjoy your search, will be un-subscribing to this one...
![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
#211
Administrator
Mr. Haskell- may i call you dave?.
glad to have you on board here if i havent mentioned it before.
i understand what you are trying to show with your pics. and i agree from that angle there would appear to be no problem with that engine. but what else besides an impact of the side seal could cause the nicks in the port that can been seen in this pic? btw you can sort of see what RG mentioned earlier. the notch in the left of the pic is only in the surface and not in the casting- you can see a little bit of the lip of the casting if you look close. that might be why the seal looks fully supported in dave haskell's pics
![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
i understand what you are trying to show with your pics. and i agree from that angle there would appear to be no problem with that engine. but what else besides an impact of the side seal could cause the nicks in the port that can been seen in this pic? btw you can sort of see what RG mentioned earlier. the notch in the left of the pic is only in the surface and not in the casting- you can see a little bit of the lip of the casting if you look close. that might be why the seal looks fully supported in dave haskell's pics
#212
I think what caused the nick in the pic. that you are talking about is from debris going into the motor. The pics. I took of the Renesis engine show that the side seal is well supported all of the time. I have seen much less support in previous 6-port engines that run at 8500 all day with no problems. BTW that nick that you speak of I have not seen on any of the engines I have built.
Dave
Dave
#213
Administrator
did the engines you built have the notch? and the impacts were caused by the side seal. no doubt about that in anyones mind that saw it. i think even dr.ianetti mentioned it when he was looking around at the various pieces on the bench.
#214
Administrator
side note- i know i am dropping names alot but seriously you had to have been there standing just out of the way and listening to jim mederer, rick engeman and dr. ianetti talk about various coatings they used or were thinking about using on the cast aluminum housings that were laying on the table and how mr.engeman had used them on some of the 3 and 4 rotor engines he's built or or is building. it was amazing. for a little they were so focused it was like the other hundred or so people in the room didnt exist to them.
#215
Registered
I truly hope it is an isolated scanario. I never said every engine had this issue. What I did say is that we saw one that did and that 2 of them had this problem there. If it is a nonissue for the RX-8 community, and I hope it is, then that is great news but it doesn't change the fact that it did happen on a couple of engines. Something caused those marks on that engine. It would be nice to know exactly what the circumstances were when it happened.
Dave: those are great pictures. Thank you for those.
Dave: those are great pictures. Thank you for those.
#216
I have not seen any of these notches that you are talking about on any motors that I have built. Did anyone see the side seal that caused this mystery notch. I'm pretty sure it would have some evidence of the crash.
Dave
Dave
#217
Administrator
sorry i may have confused things a bit with the terms i was using. for clarification purposes
nick= impact on port from sideseal as seen in circled area of first pic
notch= curve on edge of port from milling tool that i have highlighted with a red line in the second pic. also in second pic i have drawn an arrow to the little "lip" of the casting below the port surface so that you can see what i mean about the surface and casting not being the same at that area.
nick= impact on port from sideseal as seen in circled area of first pic
notch= curve on edge of port from milling tool that i have highlighted with a red line in the second pic. also in second pic i have drawn an arrow to the little "lip" of the casting below the port surface so that you can see what i mean about the surface and casting not being the same at that area.
#218
Administrator
david the original poster of this thread started by saying his side seal had indeed been worn down by hitting the port causing a larger clearance, drop in compression and loss of hp. but he did not share with us any pics he might have. the the rotors were not out on the table at racing beat for us to see. neither was the center housing although RG i believe did get a chance to look at it and the siamesed center port.
#219
Registered
They only let us look at the rear housing and the rear rotor housing since they were the ones most damaged. They said the end housing damage may still be minor enough to lap off though. We did not see the rest of the engine as the parts were still usable. They did not want others handling and potentially dropping or damaging good parts. The intermediate housing as far as I could tell had no damage at all including the side seals. I don't expect that it would. I couldn't actually handle the intermediate housing but I did see it.
There is one more possibility that could explain this mark that we saw which would cause it to be a nonissue. This is something that we should really consider. They only showed us the half of the engine that was damaged and not usable. They did not show us the front housing. When the apex seal broke, part of it could have been caught in this location as the engine rotated and caused the damage. Those seal parts get slung around inside the engine. It could just be a coincidence that it was in this location. Don't rule out the possibility that this happened. It is possible. It is just strange that the original poster of this thread found the mark in this location in his engine and that we also saw this mark at Racing Beat. The original poster is also known to be very hard on engines and the only ones that RB have taken apart so far to our knowledge have been blown engines.
I still think that there is enough side seal support area on the housing that it can not fall in. However that mark has me wondering what in fact caused it if it wasn't a side seal.
There is one more possibility that could explain this mark that we saw which would cause it to be a nonissue. This is something that we should really consider. They only showed us the half of the engine that was damaged and not usable. They did not show us the front housing. When the apex seal broke, part of it could have been caught in this location as the engine rotated and caused the damage. Those seal parts get slung around inside the engine. It could just be a coincidence that it was in this location. Don't rule out the possibility that this happened. It is possible. It is just strange that the original poster of this thread found the mark in this location in his engine and that we also saw this mark at Racing Beat. The original poster is also known to be very hard on engines and the only ones that RB have taken apart so far to our knowledge have been blown engines.
I still think that there is enough side seal support area on the housing that it can not fall in. However that mark has me wondering what in fact caused it if it wasn't a side seal.
#220
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I think the information in this thread is very interesting, even though it is pure specualtion. These type of discussions usually lead to great findings, sometimes unrelated to the original topic.
I believe however, that the moderators should rename the thread. Potential RX-8 owners logging onto this forum who are greeted by "RENESIS HAS DURABILITY PROBLEMS" (a declarative statement that has not been proven) might get scared away from Mazda. I think one thing we can all agree on is that we want Mazda to sell lots of cars and prosper, so we can continue getting support and new products from them. Scaring people won't help that.
A similar post in the UK forum claiming Canzoomer units would damage an engine was renamed for this very reason. (No hard facts proving it)
Just a thought, mods.....
I believe however, that the moderators should rename the thread. Potential RX-8 owners logging onto this forum who are greeted by "RENESIS HAS DURABILITY PROBLEMS" (a declarative statement that has not been proven) might get scared away from Mazda. I think one thing we can all agree on is that we want Mazda to sell lots of cars and prosper, so we can continue getting support and new products from them. Scaring people won't help that.
A similar post in the UK forum claiming Canzoomer units would damage an engine was renamed for this very reason. (No hard facts proving it)
Just a thought, mods.....
#221
I agree with RG if this motor in question had an apex seal break the nick was probably caused by the broken seal or debris in the motor from the seal breaking. I can't imagine that size of a nick being caused from a side seal. As an expeirment try making a nick in a side housing with a side seal. I don't think it can happen without totally destroying the side seal.
Dave
Dave
#223
Race Steward
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This thread continues to interest me. Along if's and maybe's.
It will be interesting to see the state of one of our development motors when it gets split open and checked out prior to our S/C engine dyno testing program.
In then even more interesting when we tear it down again and see what has happened.
I would be pretty skeptical about judging the "wear rates" etc. of non-failed parts that have been affected by another broken part bouncing around inside immediately after an engine lunching - especially if the failure the attributed to the wear and consequential damage.
Cheers,
Hymee.
It will be interesting to see the state of one of our development motors when it gets split open and checked out prior to our S/C engine dyno testing program.
In then even more interesting when we tear it down again and see what has happened.
I would be pretty skeptical about judging the "wear rates" etc. of non-failed parts that have been affected by another broken part bouncing around inside immediately after an engine lunching - especially if the failure the attributed to the wear and consequential damage.
Cheers,
Hymee.
#224
That's a pretty large nick in the port. Is that easy to repair, or do you have to trash the housing?
I wouldn't rule out the fact of a broken apex seal causing damage to the port. I'm certain the force would be enough to make that kind of nick.
I wouldn't rule out the fact of a broken apex seal causing damage to the port. I'm certain the force would be enough to make that kind of nick.
#225
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Seems to me that some of these pics ‘COULD’ just be showing original groves or lines that were from the casting process or handling of the casting during machining or even from poor quality machining. IE they may not be due to operation of the rotary, or ejected material. Should we not cover all possibilities here.