Renesis side seal discussion
#301
Mmmmm... Rotary Donut
Joined: Nov 2003
Posts: 2,376
Likes: 4
From: Lake in the Hills, IL (NW Chicago Burbs)
Not sure if this info has been brought up- I don't remember seeing it in the thread so far. In the Jack Yamaguchi book I mentioned earlier they mention that the in the Renesis' early development, due to the much larger intake and exhaust ports, the engineers frequently experienced the "swallowing" of the side seals as it passed over the ports. I'm assuming they meant it was passing over unsupported at some point. They go on to discuss this is why the developed the new side seals that are 1/2mm taller and 1/2mm wider (than the 13BREW) and with a trapezoidal or keystone cross section, to be stong enough to pass over the larger ports.
I also found similar supporting info in this article:
https://www.rx8club.com/showthread.p...=keystone+seal
"Previously the side seal was arched and rectangular-sectioned piece w/ a thickness of .03 in. The new engine’s side port configuration allowed significant enlargement of both intake and exhaust port opening areas. Earlier in the development stage, Mazda engineers experienced frequent breakage and “swallowing” of side seals when they traversed over the ports. A new keystone seal, .05 in thick at the top is adopted to solve this problem.
The keystone seal has a trapezoidal section, thicker at the top and tapering down at 4.5 degrees in its .14 in height."
So Mazda definitely knew that there was a potential side seal issue very early on, and they believe that the thicker, stronger side seals have sufficiently addressed this in the stock NA state. So the only question for me that remains is if the seals are strong enough to withstand boost of any kind, and if so how much.
Thoughts...?
I also found similar supporting info in this article:
https://www.rx8club.com/showthread.p...=keystone+seal
"Previously the side seal was arched and rectangular-sectioned piece w/ a thickness of .03 in. The new engine’s side port configuration allowed significant enlargement of both intake and exhaust port opening areas. Earlier in the development stage, Mazda engineers experienced frequent breakage and “swallowing” of side seals when they traversed over the ports. A new keystone seal, .05 in thick at the top is adopted to solve this problem.
The keystone seal has a trapezoidal section, thicker at the top and tapering down at 4.5 degrees in its .14 in height."
So Mazda definitely knew that there was a potential side seal issue very early on, and they believe that the thicker, stronger side seals have sufficiently addressed this in the stock NA state. So the only question for me that remains is if the seals are strong enough to withstand boost of any kind, and if so how much.
Thoughts...?
#303
Mmmmm... Rotary Donut
Joined: Nov 2003
Posts: 2,376
Likes: 4
From: Lake in the Hills, IL (NW Chicago Burbs)
Originally Posted by zoom44
well there were the oft repeated claims by Mazda people around the time of Launch that the renesis was built to take boost.
#304
I definatly think the engine was made to market more of a daily driver, but I do agree that the engine can take boost. Someone just needs to set it up the right way and tune the car correctly. The engine has more potential than alot of people are given it. It is just going to take time, and when it does reach the point that tunning and power of the engine is perfected, I think we will have access to a monster that was once underestimated.
#307
I haven't read the entire thread, so I'm not sure whether this has been asked before: But just assuming there is indeed a wear issue. Could this be from that extra soot that is produced during the combustion process? (Due to the fact that the engine runs richer than originally intended?)
Last edited by globi; 10-26-2004 at 03:24 PM.
#310
Glad you corrected it, otherwise this thread might be sooted.
(a humorous play on words, meaning probably lost with most Americans. But I'm all for a bit of cultural edumacation.)
Cheers,
Hymee.
(a humorous play on words, meaning probably lost with most Americans. But I'm all for a bit of cultural edumacation.)
Cheers,
Hymee.
#311
Teach me. "edumacation" is that the Ausie humor???
You know I'm a little slow on that English humor stuff, I can't sit through their movies.
And aren't you guys the rebels, not really fond of the UK because they threw you out of the jails??
Edumacate me.
You know I'm a little slow on that English humor stuff, I can't sit through their movies.
And aren't you guys the rebels, not really fond of the UK because they threw you out of the jails??
Edumacate me.
#313
Well, living next to the 4X brewery is not always a good thing or is it?
Talking about soot again: What if you had some carbon depositions and they somehow end up on the housing sides and then get milled by the rotors, wouldn't this cause some extra wear? (On the other hand graphite is also used as a lubricant. So considering this it might not be an issue.)
Talking about soot again: What if you had some carbon depositions and they somehow end up on the housing sides and then get milled by the rotors, wouldn't this cause some extra wear? (On the other hand graphite is also used as a lubricant. So considering this it might not be an issue.)
#314
Originally Posted by globi
What if you had some carbon depositions...
Carbon is pretty soft. Some race engines use carbon apex seals. When they break they usually don't damage the interior of the engine. Carbon inside the engine does this all the time. This isn't something you typically worry about.
#315
Now he's a communist?? Not that I don't agree, have to think about it awhile.
Well somewhere i bet there were some Carbon depositions, just need to go look it up in some law library
Well somewhere i bet there were some Carbon depositions, just need to go look it up in some law library
#318
Whatever became of this issue?
Sorry to revive it (not really sorry), but many people have passed the magic 25k mark, and the only ones who seem to be having problems are those with ATs who live in extremely hot climates.
Sorry to revive it (not really sorry), but many people have passed the magic 25k mark, and the only ones who seem to be having problems are those with ATs who live in extremely hot climates.
#320
#323
Originally Posted by RotoRocket
Whatever became of this issue?
Sorry to revive it (not really sorry), but many people have passed the magic 25k mark, and the only ones who seem to be having problems are those with ATs who live in extremely hot climates.
Sorry to revive it (not really sorry), but many people have passed the magic 25k mark, and the only ones who seem to be having problems are those with ATs who live in extremely hot climates.
#324
Originally Posted by therm8
My 4 port has 63k on it, driving exclusively in FL, GA and SC. Summertime on the streets, temps can hit 110+ rather often (and it's always very humid). Still spins like a top. But then I rarely use the AC. Car runs too hot when I do (based on continued fan operation after shutdown).
You rarely use your AC and it regularly hits 110+ there?
You're a glutton for punishment.
Nice to know your at 63k problem free, though.
My fan runs after shutdown in Michigan, too, but I've never been bothered by that. It's just doing its job.
Have you run a compression test?
#325
Originally Posted by RotoRocket
You rarely use your AC and it regularly hits 110+ there?
You're a glutton for punishment.
Nice to know your at 63k problem free, though.
My fan runs after shutdown in Michigan, too, but I've never been bothered by that. It's just doing its job.
Have you run a compression test?
You're a glutton for punishment.
Nice to know your at 63k problem free, though.
My fan runs after shutdown in Michigan, too, but I've never been bothered by that. It's just doing its job.
Have you run a compression test?
No compression test. Never felt the need. The car pulls strongly all the way to redline. I'll probably get one before getting a supercharger (though the car may have 200k on it by then ), just to be sure.
I've become used to no AC. On the highway, windows down works enough for me. In stop and go at 110F, the AC is worthless anyway, so I just sweat . The reported temp doesn't actually get that high, but with all the heat coming off the pavement, the in-car and various bank thermometers get up there regularly in July and August.
My fans will sometimes run for 5-10minutes after shutdown, even after babying the car with the AC on. I don't like having the coolant temp skyrocket with no forced flow through the radiator, so I try to take it easy on her in the summer. The fans rarely run, and never for more than 30 seconds, as I drive it now. A cool rotary is a happy one in my book .