Rotary Aviation apex seal report
09-12-05, 07:12 PM
#151
I wish I was driving!
Originally Posted by t-von
Would you mind doing a basic compression check before the tear down?
EDIT: hot compression.
Last edited by scathcart; 09-12-05 at 07:22 PM.
09-12-05, 08:23 PM
#153
Junior Member
Join Date: Jul 2003
Location: Sydney, Australia
Posts: 48
Likes: 0
Received 0 Likes
on
0 Posts
My 3000km old engine lost compression in the rear rotor at a track day yesterday.
It had been losing compression slowly anyway.
Comp before removal was front 4.3, 4.3, 4.9. Rear 4.4, 0, 0. or thereabouts.
Engine came out last night, looking in the exh ports looks to me like a collapsed apex spring. Tearing down tonight & will update on the damage.
It had been losing compression slowly anyway.
Comp before removal was front 4.3, 4.3, 4.9. Rear 4.4, 0, 0. or thereabouts.
Engine came out last night, looking in the exh ports looks to me like a collapsed apex spring. Tearing down tonight & will update on the damage.
09-12-05, 09:51 PM
#154
Originally Posted by KillerRx4
My 3000km old engine lost compression in the rear rotor at a track day yesterday.
It had been losing compression slowly anyway.
Comp before removal was front 4.3, 4.3, 4.9. Rear 4.4, 0, 0. or thereabouts.
Engine came out last night, looking in the exh ports looks to me like a collapsed apex spring. Tearing down tonight & will update on the damage.
It had been losing compression slowly anyway.
Comp before removal was front 4.3, 4.3, 4.9. Rear 4.4, 0, 0. or thereabouts.
Engine came out last night, looking in the exh ports looks to me like a collapsed apex spring. Tearing down tonight & will update on the damage.
09-13-05, 08:13 AM
#155
Junior Member
Join Date: Jul 2003
Location: Sydney, Australia
Posts: 48
Likes: 0
Received 0 Likes
on
0 Posts
Well a fair bit more damage than I expected.
RA apex seals survived with no damage other than some warpage.
Completely flattened a pair of apex seal springs in the rear rotor.
3 broken corner seals in the rear rotor ( 1 open side, 2 gear side).
2 broken corner seals front rotor (gear side).
1 very badly broken side seal front rotor (open side).
badly dented reat rotor on 1 face & slight dents on the other 2 faces.
End & Intermediate housings look good.
Rotor housings have alot of wear for the 3000km running time since the build.
These same housings had done maybe 5000km since i fitted it & unknown amount of km in japan.
Heres some pics.
RA apex seals survived with no damage other than some warpage.
Completely flattened a pair of apex seal springs in the rear rotor.
3 broken corner seals in the rear rotor ( 1 open side, 2 gear side).
2 broken corner seals front rotor (gear side).
1 very badly broken side seal front rotor (open side).
badly dented reat rotor on 1 face & slight dents on the other 2 faces.
End & Intermediate housings look good.
Rotor housings have alot of wear for the 3000km running time since the build.
These same housings had done maybe 5000km since i fitted it & unknown amount of km in japan.
Heres some pics.
09-13-05, 04:55 PM
#158
Damn that looks bad. Was this car turbo? You must of had some major fuel starvation since you lost both front and rear.
Hmm I also wonder if the heavier weight of these RA seals also makes a difference in the housing wear?
Hmm I also wonder if the heavier weight of these RA seals also makes a difference in the housing wear?
Last edited by t-von; 09-13-05 at 05:18 PM.
09-13-05, 05:58 PM
#159
Junior Member
Join Date: Jul 2003
Location: Sydney, Australia
Posts: 48
Likes: 0
Received 0 Likes
on
0 Posts
That is just 1 rotor housing (the worst of the 2) the other shows same wear pattern just not quite as bad.
It is a turbo engine was running & 17psi on 98 RON fuel. It was tuned 1 week prior to the track day.
It is possible it starved of fuel due to running it too low on fuel but I dont think so.
It actually felt like it ran out of fuel for a second & looking at the gauge read empty, I pulled into pit lane & fuel gauge returned to under 1/4 tank. It does have a surge tank btw.
It is a turbo engine was running & 17psi on 98 RON fuel. It was tuned 1 week prior to the track day.
It is possible it starved of fuel due to running it too low on fuel but I dont think so.
It actually felt like it ran out of fuel for a second & looking at the gauge read empty, I pulled into pit lane & fuel gauge returned to under 1/4 tank. It does have a surge tank btw.
09-14-05, 09:13 PM
#163
Freedoms worth a buck o'5
Join Date: May 2001
Location: Calgary Alberta Canada
Posts: 2,544
Likes: 0
Received 1 Like
on
1 Post
T-von, now have a good look at that motor Killer Rx-4 posted, this is what I have trying to get you to understand for the last of my god knows how many posts, did RA seals save that motor at all? No its pretty much totally shitted... Bionic seals or not, detonation kills and having stronger seals just shifts the damage down the line...
As for the rotors I posted about that were dented, I built the motor, they werent dented when it went together... yes Mazda seals (2 piece) survived rotor denting detonation..
As for the rotors I posted about that were dented, I built the motor, they werent dented when it went together... yes Mazda seals (2 piece) survived rotor denting detonation..
09-15-05, 12:52 AM
#164
Originally Posted by Maxthe7man
T-von, now have a good look at that motor Killer Rx-4 posted, this is what I have trying to get you to understand for the last of my god knows how many posts, did RA seals save that motor at all? No its pretty much totally shitted... Bionic seals or not, detonation kills and having stronger seals just shifts the damage down the line...
As for the rotors I posted about that were dented, I built the motor, they werent dented when it went together... yes Mazda seals (2 piece) survived rotor denting detonation..
As for the rotors I posted about that were dented, I built the motor, they werent dented when it went together... yes Mazda seals (2 piece) survived rotor denting detonation..
Ahh I already saw the damage. I guess you missed my post about 5 post up? Sure the housings look bad but really look at the damage? The end plates didn't crack. Those housings can be resurfaced. I strongly believe the stock seals wouldn't have survived this kind of detonation. The housings would be scored beyond repair + you still would have the potential of the seal pieces taking out the turbine blades. This didn't happen to this engine.
I'll still remain optimistic about the seals until more reports come in. You never know, there may be certain conditions needed to make the seals usable in these engines. It could be somthing simple as just using Moble one synthetic 2 cycle oil in a direct feed to the omp? I mean hell just imagine if the right combination with these seals were able to allow a rotary to make 500+hp and last over 100k without the seals really wearing down? That's 2JZ type reliability. Thats how I look at this. Just because you have some damage doesn't mean that we all should jump ship and use something else without more R&D. If Felix Wankel took that approach, we wouldn't have the rotary today.
Last edited by t-von; 09-15-05 at 01:02 AM.
09-15-05, 07:23 AM
#165
Freedoms worth a buck o'5
Join Date: May 2001
Location: Calgary Alberta Canada
Posts: 2,544
Likes: 0
Received 1 Like
on
1 Post
Originally Posted by t-von
Ahh I already saw the damage. I guess you missed my post about 5 post up? Sure the housings look bad but really look at the damage? The end plates didn't crack. Those housings can be resurfaced. I strongly believe the stock seals wouldn't have survived this kind of detonation. The housings would be scored beyond repair + you still would have the potential of the seal pieces taking out the turbine blades. This didn't happen to this engine.
I'll still remain optimistic about the seals until more reports come in. You never know, there may be certain conditions needed to make the seals usable in these engines. It could be somthing simple as just using Moble one synthetic 2 cycle oil in a direct feed to the omp? I mean hell just imagine if the right combination with these seals were able to allow a rotary to make 500+hp and last over 100k without the seals really wearing down? That's 2JZ type reliability. Thats how I look at this. Just because you have some damage doesn't mean that we all should jump ship and use something else without more R&D. If Felix Wankel took that approach, we wouldn't have the rotary today.
I'll still remain optimistic about the seals until more reports come in. You never know, there may be certain conditions needed to make the seals usable in these engines. It could be somthing simple as just using Moble one synthetic 2 cycle oil in a direct feed to the omp? I mean hell just imagine if the right combination with these seals were able to allow a rotary to make 500+hp and last over 100k without the seals really wearing down? That's 2JZ type reliability. Thats how I look at this. Just because you have some damage doesn't mean that we all should jump ship and use something else without more R&D. If Felix Wankel took that approach, we wouldn't have the rotary today.
There is no right combination besides those seals and the garbage can...Face it..
09-15-05, 02:26 PM
#166
Originally Posted by Maxthe7man
God man, sugar coat it all you want...The proof is there, that motor is toast, and that resurfacing stuff is another bunch of up in the air wonder bar technology that seems to be 50/50 at best as well and no cheaper than FD housings..... Look at it again, should that motor have run mazda seals, and one let go, early on, he would have been farther ahead, there is no doubt..No the stock seals would not have survived from that detonation, but for the last freaking time, add it up, those apex seals are fucked anyway, they are warped, and to add that , rotors and housings...
There is no right combination besides those seals and the garbage can...Face it..
There is no right combination besides those seals and the garbage can...Face it..
Dude you need to chill out! The stock seals would have let go sooner. I've seen pics were just one apex seal completely took out a rotor, housing, and turbo. All it takes is one seal to let go and take out everything else in that chamber because of all the broken pieces detonation or not. Then you have to worry about all the little pieces going through the exhaust port to the turbo. Housings gaulged by broken seals are not repairable. Whether or not you believe in the re-surfacing process doesn't change the fact that those housings are repairable. So don't tell me he could have been farther ahead.
You also have to consider the fact that the engine still had enough compression to remain operational. This same engine with stock seals would have zero compression on both rotor faces and you know it. Thats why the seals are good for airplane applications. You blow an engine at 20,000ft with the RA seals at least you still have enough compression to keep the engine rotating. If you blow the engine with stock seals, zero compression isn't going to help you fly the plane.
Last edited by t-von; 09-15-05 at 02:41 PM.
09-15-05, 04:14 PM
#167
Senior Member
Join Date: Apr 2001
Location: salt lake, utah, usa
Posts: 454
Likes: 0
Received 0 Likes
on
0 Posts
i agree. there's no need to get so emotionally involved in this, so what if someone else has a different opinion. this is about wheather one seal is better than the other and in what way. there is no right answer because they both have their benefits and drawbacks, it's just like the synthetic versus dyno oil debate, or the 3mm versus 2mm debate, it all boils down to what the person that owns the engine decides is a better fit for their application. i just blew a motor on the ra seals and have yet to tear it down to see the damage. i have blown two on mazda seals and between the two of them i had two reusable rotors and one reusable housing, none of the irons were damaged. until i find out what happened inside my ra motor i am leaning towards using them again just because of how much damage i saw with the mazda seals, but that may change if the ra seals did more damage. my main concern is that the apex seal grooves don't get worn out of spec, because i am not really too excited about replacing rotors.
09-15-05, 04:43 PM
#168
Originally Posted by yodaddy
i agree. there's no need to get so emotionally involved in this, so what if someone else has a different opinion. this is about wheather one seal is better than the other and in what way. there is no right answer because they both have their benefits and drawbacks, it's just like the synthetic versus dyno oil debate, or the 3mm versus 2mm debate, it all boils down to what the person that owns the engine decides is a better fit for their application.
This has been exactly my point. Thx!
09-15-05, 06:28 PM
#169
Freedoms worth a buck o'5
Join Date: May 2001
Location: Calgary Alberta Canada
Posts: 2,544
Likes: 0
Received 1 Like
on
1 Post
Originally Posted by t-von
Dude you need to chill out! The stock seals would have let go sooner. I've seen pics were just one apex seal completely took out a rotor, housing, and turbo. All it takes is one seal to let go and take out everything else in that chamber because of all the broken pieces detonation or not. Then you have to worry about all the little pieces going through the exhaust port to the turbo. Housings gaulged by broken seals are not repairable. Whether or not you believe in the re-surfacing process doesn't change the fact that those housings are repairable. So don't tell me he could have been farther ahead.
You also have to consider the fact that the engine still had enough compression to remain operational. This same engine with stock seals would have zero compression on both rotor faces and you know it. Thats why the seals are good for airplane applications. You blow an engine at 20,000ft with the RA seals at least you still have enough compression to keep the engine rotating. If you blow the engine with stock seals, zero compression isn't going to help you fly the plane.
You also have to consider the fact that the engine still had enough compression to remain operational. This same engine with stock seals would have zero compression on both rotor faces and you know it. Thats why the seals are good for airplane applications. You blow an engine at 20,000ft with the RA seals at least you still have enough compression to keep the engine rotating. If you blow the engine with stock seals, zero compression isn't going to help you fly the plane.
Dont give me this it would have been good at 20,000 feet bullshit either, my RA motor got to the point it wouldnt start at all, with no broken seals, htey warped so bad it had nothing, I have driven blown mazda seal motors home...In my first Rx-7 way back in 1988, I drove the car for more than 2 weeks with a blown rear rotor, started every day, and ran.. My ra motor, was hit miss, it started if you spent enough time waiting for it to cool down, if it stalled hot, you were hooped..Good luck at 20,000 ft with that..
Do you have any experience with RA seals, and warped RA seals, judging by your responses I would say not...You are trying to justify the cause of a bad motor as it saviour, that makes little to no sense... And then spending 20 bucks to save 10, there is no common sense in that approach..You argue against mazda seals on the basis of tuning or what if something else goes wrong, for the million freaking time, and if KillerRx-4's posts arent enough to sink it into you, if that happens, someting else just breaks anyway, and you get to discover your super cryptonite seals just ate both housings and both rotors, and that both your detonated and undetonated housings and rotors are now garbage..
Bottom line, use Mazda OEM parts, they cant be beat, for performance, durability or price, hell the mazda seals are cheaper here than the RA seals now...Max
09-15-05, 06:34 PM
#170
Freedoms worth a buck o'5
Join Date: May 2001
Location: Calgary Alberta Canada
Posts: 2,544
Likes: 0
Received 1 Like
on
1 Post
Originally Posted by yodaddy
i agree. there's no need to get so emotionally involved in this, so what if someone else has a different opinion. this is about wheather one seal is better than the other and in what way. there is no right answer because they both have their benefits and drawbacks, it's just like the synthetic versus dyno oil debate, or the 3mm versus 2mm debate, it all boils down to what the person that owns the engine decides is a better fit for their application. i just blew a motor on the ra seals and have yet to tear it down to see the damage. i have blown two on mazda seals and between the two of them i had two reusable rotors and one reusable housing, none of the irons were damaged. until i find out what happened inside my ra motor i am leaning towards using them again just because of how much damage i saw with the mazda seals, but that may change if the ra seals did more damage. my main concern is that the apex seal grooves don't get worn out of spec, because i am not really too excited about replacing rotors.
Both the RA and the 3mm stuff suffers from the same fault, the secondary affects are worse than the initial damage they are trying to eliminate, in both cases..
Last edited by Maxthe7man; 09-15-05 at 06:43 PM.
09-15-05, 07:29 PM
#171
Originally Posted by Maxthe7man
Thats total bull, the only engine I have seen with nearly zero compression on both rotors was one built with RA seals...
I'm not going to go back and forward with you on this. My current NA engine in my 91 vert right now has zero compression on the rear rotor. Zero is zero regardless if only one chamber is working. The engine above had major lean conditions that effected both chambers. If that engine was built with the stock seals, you would probably have zero compression on both chambers. Fuel starvation will effect both chambers not just the rear. The only way zero compression will happen is if you loose at least 2 apex seals because one will affect the compression on two chambers. Also 6 months ago I took apart a NA engine from an 87 RX7 and it two had no compression on the rear. After disassembly two rear seals were broken. Like I said all it takes is one seal to let go to take out everything else.
Last edited by t-von; 09-15-05 at 07:50 PM.
09-15-05, 07:35 PM
#172
Originally Posted by Maxthe7man
Dont give me this it would have been good at 20,000 feet bullshit either, my RA motor got to the point it wouldnt start at all, with no broken seals, htey warped so bad it had nothing, I have driven blown mazda seal motors home...In my first Rx-7 way back in 1988, I drove the car for more than 2 weeks with a blown rear rotor, started every day, and ran.. My ra motor, was hit miss, it started if you spent enough time waiting for it to cool down, if it stalled hot, you were hooped..Good luck at 20,000 ft with that..
You do realized that you are still bitching about the seals from the first batch? We already know those seals were ****!
Last edited by t-von; 09-15-05 at 07:52 PM.
09-15-05, 07:37 PM
#173
Originally Posted by Maxthe7man
This is not an issue of opinion, there is a right and wrong here,
Yes Master! What ever you say Master. All hail the new Master. You are always right and we are not allowed to even have an opinion.
Last edited by t-von; 09-15-05 at 07:40 PM.
09-15-05, 07:54 PM
#174
Freedoms worth a buck o'5
Join Date: May 2001
Location: Calgary Alberta Canada
Posts: 2,544
Likes: 0
Received 1 Like
on
1 Post
Originally Posted by t-von
You do realized that you are still bitching about the seals from the first batch? We already know those seals were ****!
actually, sillier...Not so, round 2 are starting to exhibit the same problems..... I have 2 more track days, then the motor is coming apart.... if it makes that far...]
Having an opinion is one thing, you passing your opinion off as fact with no experinece on what you are talking about is another....
Last edited by Maxthe7man; 09-15-05 at 07:56 PM.
09-15-05, 09:20 PM
#175
Senior Member
Join Date: Apr 2001
Location: salt lake, utah, usa
Posts: 454
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Maxthe7man
This is not an issue of opinion, there is a right and wrong here, What you should be looking for is why you keep blowing motors, not which seal someone "thinks" is better because it kills a motor from shear heavy wear instead of detonation breakage..
Both the RA and the 3mm stuff suffers from the same fault, the secondary affects are worse than the initial damage they are trying to eliminate, in both cases..
Both the RA and the 3mm stuff suffers from the same fault, the secondary affects are worse than the initial damage they are trying to eliminate, in both cases..