compression results
08-02-2015, 09:28 AM
#101
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Failing? If you mean by Mazda's 6.9 standard then yes however I know a few rebuilders in the UK and they say that R3s have lower compression than the S1. They have tested many. Also, ported S1 engines with only like 8k on them can be as low as 6.9. I've seen a S1 with 20k with 6.9 results, no issues starting hot, 1-2 seconds.
If I had that R3, with regular oil changes, beeping and premixing, it should be good for at least another 30k-40k. It would take me more than 10 years to do that mileage.
If I had that R3, with regular oil changes, beeping and premixing, it should be good for at least another 30k-40k. It would take me more than 10 years to do that mileage.
They use the same specs but that doesn't stop the fact that on average S2s test lower than S1s. This is coming from multiple reputable rebuilders who have tested many R3s. That engine still has lots of life left in it. In no way is it is almost failing other than the Mazda standard of 6.9 @ 250 rpm. It won't show any issues or symptons until compression drops well below 6. Then you could say it's almost failing. Still seen plenty of mid/high 5s running without any issues starting hot or in performance.
That said, R3s go for about the equivalent of $9,000 or less here and a ported rebuild is about $4500 so there's less at stake.
As I said, good luck finding an R3 with much better results than that. That car will be fine for a long time with proper care.
That said, R3s go for about the equivalent of $9,000 or less here and a ported rebuild is about $4500 so there's less at stake.
As I said, good luck finding an R3 with much better results than that. That car will be fine for a long time with proper care.
08-02-2015, 12:11 PM
#102
You gonna eat that?
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08-02-2015, 12:27 PM
#103
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1. Remove the engine cover.
2. Verify that the battery is fully charged. (See BATTERY INSPECTION.)
3. Warm up the engine.
4. To decrease the exhaust system temperature, stop the engine and leave it as it is for approx. 10 min.
2. Verify that the battery is fully charged. (See BATTERY INSPECTION.)
3. Warm up the engine.
4. To decrease the exhaust system temperature, stop the engine and leave it as it is for approx. 10 min.
Not to mention that a cold engine will also increase compression scores.
So I'm not sure which direction you are trying to give here.
08-02-2015, 01:53 PM
#105
You gonna eat that?
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08-02-2015, 03:48 PM
#106
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So one car which still reads 7.3 at it's lowest and you think you've proved your point. Ok. In the beginning of this thread a car which also had a lowest reading of 7.3 was almost a fail according to you.
Lowest reading 7.3
Mod Edit: 2nd quote and it's reply removed. The post you quoted entirely acceptable, your response was not.
Lowest reading 7.3
Mod Edit: 2nd quote and it's reply removed. The post you quoted entirely acceptable, your response was not.
Last edited by RIWWP; 08-02-2015 at 08:21 PM.
08-02-2015, 05:47 PM
#107
So what is the consensus. Is my engine failing? Getting close to it?
Last edited by Gravey; 08-04-2015 at 12:04 PM.
Those S1 guys be hatin' cause they're jealous! 
08-02-2015, 10:03 PM
#111
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Not to hijack this thread or post irrelevant information, but my 05 Shinka at 117K miles was recently deemed to be failing the compression test by the dealership. They said with 7.9 as being the minimum spec, the readings for one of my rotors were 7.2, 7.1, 7.0. This is my third engine, and it has only been running for about 43K miles. Although I have no problems with hot starts, I started to notice rough idling in the summer heat after the engine has been fully warmed. Also, the shifter **** would vibrate more than it should especially with the AC on. And it doesn't seem to be producing as much power as it used to when I try to do 0-60.
The good news is Mazda will be covering the cost of the replacement engine (I pay labor) even after it's out of warranty! I posted details in this thread.
https://www.rx8club.com/rx-8-discuss...2/#post4703773
The good news is Mazda will be covering the cost of the replacement engine (I pay labor) even after it's out of warranty! I posted details in this thread.
https://www.rx8club.com/rx-8-discuss...2/#post4703773
08-03-2015, 04:30 AM
#112
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08-03-2015, 04:43 AM
#113
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Do you have the 2009 spec sheet? The one in your other post is 2011. I started a tread here years ago when I was a Mazda parts manager when these 2009 specific changes came out. Maybe I mis-read the info I received on the gearing. All these years I was under the impression the R3 had the 4.77 rear and not the other models. Maybe that changed in 2010 and 2011?
RS08-27-100H Rear Diff 4.777 (All Series 2 RX-8 Manual Trans LSD), LHD and RHD markets.
RS06-27-100G Rear Diff 4.300 (All Series 2 RX-8 Auto Trans LSD) LHD and RHD markets.
RA13-27-100M Rear Diff (Series 2 Auto trans without LSD)*
* Only shown in US EPC, I don't think many of these cars were imported into the States.
SERIES 1.
RA13-27-100M Rear Diff Normal, High Power
RA14-27-100L Rear Diff Auto Trans NO LSD (2005 Shinka)
RS02-27-100M Rear Diff Auto Trans with LSD (2008)
RS03-27-100N Rear Diff Manual Trans LSD 'Special'
RS04-27-100P Rear Diff Manual Trans LSD 'Sports'
08-03-2015, 05:42 AM
#114
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I fine with being proved otherwise. I'm just going off the numbers I've seen. I'm confused that certain users started insulting me rather than having a discussion on why they think otherwise. I wonder if that's how they react in their day to day lives when they disagree with someone or perhaps they just save it to vent out on the internet.
08-03-2015, 09:10 AM
#115
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So one car which still reads 7.3 at it's lowest and you think you've proved your point. Ok. In the beginning of this thread a car which also had a lowest reading of 7.3 was almost a fail according to you.
Lowest reading 7.3
Mod Edit: 2nd quote and it's reply removed. The post you quoted entirely acceptable, your response was not.
Lowest reading 7.3
Mod Edit: 2nd quote and it's reply removed. The post you quoted entirely acceptable, your response was not.
My point is that you don't know an average for S2 RX-8's, you are just parroting information from an unreliable source.
Last edited by 9krpmrx8; 08-03-2015 at 09:18 AM.
08-03-2015, 11:18 AM
#117
2011 R3, per my first post in this thread.
Something to scare you even more: Jeff of Maztech actually tested the car first, and got worse numbers: two of the faces on Rotor 1 were near Mazda's condemnation point when normalized to 250, as was the difference between rotor averages. That's why it went to the dealership in the first place.
Here's the first set of readings, from Maztech:
Rotor 1 (275 RPM)
7.7
7.2
7.1
Rotor 2 (275 RPM)
7.7
8.0
7.9
Again, this was BEFORE the dealership tested it. The numbers I posted before were the DEALERSHIP'S numbers.
Jeff said he perceived zero unseemly issues with vibrations, power, or hot starts. He thought the car was 100% fine and told me to buy it anyway. I just wanted it to go to the dealership first as a precaution.
Again, this was at ~21.1k miles. Car now has ~41.6k and still takes hot starts like a champ.
Something to scare you even more: Jeff of Maztech actually tested the car first, and got worse numbers: two of the faces on Rotor 1 were near Mazda's condemnation point when normalized to 250, as was the difference between rotor averages. That's why it went to the dealership in the first place.
Here's the first set of readings, from Maztech:
Rotor 1 (275 RPM)
7.7
7.2
7.1
Rotor 2 (275 RPM)
7.7
8.0
7.9
Again, this was BEFORE the dealership tested it. The numbers I posted before were the DEALERSHIP'S numbers.
Jeff said he perceived zero unseemly issues with vibrations, power, or hot starts. He thought the car was 100% fine and told me to buy it anyway. I just wanted it to go to the dealership first as a precaution.
Again, this was at ~21.1k miles. Car now has ~41.6k and still takes hot starts like a champ.
Last edited by IamFodi; 08-03-2015 at 11:20 AM.
08-03-2015, 11:40 AM
#118
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2011 R3, per my first post in this thread.
Something to scare you even more: Jeff of Maztech actually tested the car first, and got worse numbers: two of the faces on Rotor 1 were near Mazda's condemnation point when normalized to 250, as was the difference between rotor averages. That's why it went to the dealership in the first place.
Here's the first set of readings, from Maztech:
Rotor 1 (275 RPM)
7.7
7.2
7.1
Rotor 2 (275 RPM)
7.7
8.0
7.9
Again, this was BEFORE the dealership tested it. The numbers I posted before were the DEALERSHIP'S numbers.
Jeff said he perceived zero unseemly issues with vibrations, power, or hot starts. He thought the car was 100% fine and told me to buy it anyway. I just wanted it to go to the dealership first as a precaution.
Again, this was at ~21.1k miles. Car now has ~41.6k and still takes hot starts like a champ.
Something to scare you even more: Jeff of Maztech actually tested the car first, and got worse numbers: two of the faces on Rotor 1 were near Mazda's condemnation point when normalized to 250, as was the difference between rotor averages. That's why it went to the dealership in the first place.
Here's the first set of readings, from Maztech:
Rotor 1 (275 RPM)
7.7
7.2
7.1
Rotor 2 (275 RPM)
7.7
8.0
7.9
Again, this was BEFORE the dealership tested it. The numbers I posted before were the DEALERSHIP'S numbers.
Jeff said he perceived zero unseemly issues with vibrations, power, or hot starts. He thought the car was 100% fine and told me to buy it anyway. I just wanted it to go to the dealership first as a precaution.
Again, this was at ~21.1k miles. Car now has ~41.6k and still takes hot starts like a champ.
You are brave. Hot starts doesn't mean a whole lot with the S2 starter, we started an engine with a cracked apex seals with a S2 starter just for ***** and giggles.
I would go dyno with another 8 on the same day or do a 3rd gear pull versus a known solid RX-8, that will tell you what it really has in it. Lot's of people drive around with a low compression engine and don't even know it.
One year at the Texas8 I vacuum tested a bunch of rx8's and most of those who had low numbers got new engines soon after. But all those cars drove all day without a real issue and they really didn't notice the power loss until they had a healthy 8 in front of them.
08-03-2015, 03:00 PM
#119
You are brave. Hot starts doesn't mean a whole lot with the S2 starter, we started an engine with a cracked apex seals with a S2 starter just for ***** and giggles.
I would go dyno with another 8 on the same day or do a 3rd gear pull versus a known solid RX-8, that will tell you what it really has in it. Lot's of people drive around with a low compression engine and don't even know it.
One year at the Texas8 I vacuum tested a bunch of rx8's and most of those who had low numbers got new engines soon after. But all those cars drove all day without a real issue and they really didn't notice the power loss until they had a healthy 8 in front of them.
I would go dyno with another 8 on the same day or do a 3rd gear pull versus a known solid RX-8, that will tell you what it really has in it. Lot's of people drive around with a low compression engine and don't even know it.
One year at the Texas8 I vacuum tested a bunch of rx8's and most of those who had low numbers got new engines soon after. But all those cars drove all day without a real issue and they really didn't notice the power loss until they had a healthy 8 in front of them.
Like I said, the Mazda dealer got better numbers afterward, which made me feel like the engine might simply have had too easy a life before and just needed to run a bit. Worst-case scenario, the numbers really were that low, in which case it'd die well before 100k and get replaced under warranty.
08-04-2015, 03:08 AM
#120
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It's all about the averages, and average of 7.3 is failing, pay attention. The averages of Gravey's car (not sure what mileage) are 7.6 @300RPM (still solidly within spec) and 8.4 @260RPM (as good as I have ever seen on a renny).
My point is that you don't know an average for S2 RX-8's, you are just parroting information from an unreliable source.
My point is that you don't know an average for S2 RX-8's, you are just parroting information from an unreliable source.
'Pay attention'? Take your own advice. I said 'they test lower on average'. I didn't rule out that some would be good. The first car in this thread had about an average of 7.4 across both faces and you said:
Now .2 higher on average with the same lowest reading and you got all excited, quoting my previous posts and posting smiley faces.
As for 'parroting information from an unreliable source.' Putting aside what rebuilders have told me. There's 5 S2s in this thread, 4 of them you yourself deem too low and the other barely makes it by .2 with uneven wear then there are at least 3 more examples on the UK forums. Perhaps the data set is small but it has grown since this thread started and they do seem to be testing lower on average. Unless you mean the people posting results are an 'unreliable source'?
08-04-2015, 07:26 AM
#122
Speaking of averages, a lot of the S1 numbers posted on this site are damn low... Wonder what the global average of posted numbers is.
08-04-2015, 08:13 AM
#123
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There would be a correlation between people who think their engines are failing and low scores. This does not equate to the same thing as S2 engines are always lower, or that they start lower.
If you look through threads with S1 compression tests, these are all rather better than S1 compression scores, but again, most of those are because people think their engine is failing... and it is.
When I went looking for a replacement RX-8, 3 of the 4 RX-8s I had tested (all S1s) had numbers in the 5s and 6s, the 4th was 6.9, 7.0, 7.1s. I finally went and bought back the RX-8 I had sold 2 years prior, at 30,000 miles on a reman it's scores are still in the mid to high 7s.
So if you go looking for low scores in an environment of people thinking they have engine issues, you are going to easily find them. It's much much harder to get someone to test their very low mileage healthy engine.
Gravey is a Canadian exception
And his scores show how much higher they can be. Yes, he has a single low face, probably a sticking side seal he can get loosened back up, but that's not his average score, his average score is 8.03 even with that sticking face, which is extremely healthy, not "below average". His lowest score is higher than the average you are pushing, "high 6s".Fodi's average is lower, but still above the average you were finding acceptable (his lowest was also a 7.3), and he feels that the engine is continuing to improve, not get worse.
Another thing to think about is that a lot of crappy scores doesn't mean it's acceptable. Anyone that feels they can build a healthy engine that only tests 6.9 is a crappy engine builder. Period. There are several builders that consistently get into the 8s. And the performance difference is VERY noticeable if you drive the two cars back to back.
08-04-2015, 09:07 AM
#125
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I did consider this but we're not talking about people who think they're engines are failing.
I said this a few times now in previous posts;