Another engine replacement
04-22-2009, 03:28 PM
#26
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Compression test results
I got the compression test results from my shop, although they were hand-written and not in a graph form like I'd hoped.
Here's what I was given:
Rotor #1
RPM: 189
05.4
05.5
05.4
Rotor #2
RPM: 192
05.8
05.7
05.7
Unfortunately I wasn't given the PSI readings for each, but these numbers are definitely below spec.
I really wanted to get the car on a dyno before it went in, but I didn't have the time. At this stage, is there any power loss associated with these low compression problems?
Here's what I was given:
Rotor #1
RPM: 189
05.4
05.5
05.4
Rotor #2
RPM: 192
05.8
05.7
05.7
Unfortunately I wasn't given the PSI readings for each, but these numbers are definitely below spec.
I really wanted to get the car on a dyno before it went in, but I didn't have the time. At this stage, is there any power loss associated with these low compression problems?
04-22-2009, 05:55 PM
#27
Certified Mazda Tech
I got the compression test results from my shop, although they were hand-written and not in a graph form like I'd hoped.
Unfortunately I wasn't given the PSI readings for each, but these numbers are definitely below spec.
I really wanted to get the car on a dyno before it went in, but I didn't have the time. At this stage, is there any power loss associated with these low compression problems?
Unfortunately I wasn't given the PSI readings for each, but these numbers are definitely below spec.
I really wanted to get the car on a dyno before it went in, but I didn't have the time. At this stage, is there any power loss associated with these low compression problems?
edit, lmfao talk about borderline here's simply the results when typed into my compression calculator, check out the results (basically that 5.4 @ 189 rpm is roughly 6.9ish @ 250rpm making it BARELY under spec, 5.5 @ 189 is probably 7.0-7.05ish). See attached pic of results from my comp calculator. All in all 5.8 at 192rpm converted to 250 is 7.21482952, or 7.2, so your highest face is still on the fence as well. Either way 2 "spec" failed faces are 2 "spec" failed faces and by standards the motor should be replaced.
BTW you were in fact given "psi readings"...just not in psi. the numbers you have are kgf/cm2 (kilogram force per square centimeter), which is kpa x 100, kPa (kilopascal) = 0.145037738 psi. it's a metric measurement. kgf/cm2 is close to "bar" measurements (1kgf/cm2= .981 bar, 1 bar = 1.02kgf/cm2)
As far as a possible "loss of power" the whole motor being basically borderline would be a loss of power, harder hard starts, possible hot stalls, etc. I have seen all around "low motors" that drive good.
kevin.
Last edited by teknics; 04-22-2009 at 11:29 PM.
04-22-2009, 06:08 PM
#28
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Actually converted to the *proper* RPM of 250rpm those numbers are probably fairly close to spec, let me figure out how to convert it to 250rpm, uno minuto.
edit, lmfao talk about borderline here's simply the results when typed into my compression calculator, check out the results (basically that 5.4 @ 189 rpm is roughly 6.9ish @ 250rpm making it BARELY under spec). See attached pic of results from my comp calculator. All in all i have a feeling 5.8 at 192rpm converted to 250 should put it in the mid 7's at least.
BTW you were in fact given "psi readings"...just not in psi. the numbers you have are kgf/cm2, which is kpa x 100, kPa = 0.145037738 psi.
kevin.
edit, lmfao talk about borderline here's simply the results when typed into my compression calculator, check out the results (basically that 5.4 @ 189 rpm is roughly 6.9ish @ 250rpm making it BARELY under spec). See attached pic of results from my comp calculator. All in all i have a feeling 5.8 at 192rpm converted to 250 should put it in the mid 7's at least.
BTW you were in fact given "psi readings"...just not in psi. the numbers you have are kgf/cm2, which is kpa x 100, kPa = 0.145037738 psi.
kevin.
Btw, that's a great little program you have!
04-22-2009, 09:30 PM
#29
Actually converted to the *proper* RPM of 250rpm those numbers are probably fairly close to spec, let me figure out how to convert it to 250rpm, uno minuto. (BTW spec is 7.0 @ 250 rpm and above is considered "good", anything lower @ 250rpm is "bad")
edit, lmfao talk about borderline here's simply the results when typed into my compression calculator, check out the results (basically that 5.4 @ 189 rpm is roughly 6.9ish @ 250rpm making it BARELY under spec, 5.5 @ 189 is probably 7.0-7.05ish). See attached pic of results from my comp calculator. All in all i have a feeling 5.8 at 192rpm converted to 250 should put it in the mid 7's at least.
BTW you were in fact given "psi readings"...just not in psi. the numbers you have are kgf/cm2 (kilogram force per square centimeter), which is kpa x 100, kPa (kilopascal) = 0.145037738 psi. it's a metric measurement.
As far as a possible "loss of power" the whole motor being basically borderline would be a loss of power, harder hard starts, possible hot stalls, etc. I have seen all around "low motors" that drive good.
kevin.
edit, lmfao talk about borderline here's simply the results when typed into my compression calculator, check out the results (basically that 5.4 @ 189 rpm is roughly 6.9ish @ 250rpm making it BARELY under spec, 5.5 @ 189 is probably 7.0-7.05ish). See attached pic of results from my comp calculator. All in all i have a feeling 5.8 at 192rpm converted to 250 should put it in the mid 7's at least.
BTW you were in fact given "psi readings"...just not in psi. the numbers you have are kgf/cm2 (kilogram force per square centimeter), which is kpa x 100, kPa (kilopascal) = 0.145037738 psi. it's a metric measurement.
As far as a possible "loss of power" the whole motor being basically borderline would be a loss of power, harder hard starts, possible hot stalls, etc. I have seen all around "low motors" that drive good.
kevin.
Cool program. Here are my numbers at 73K on the motor:
Rear Rotor @ 294 RPM
6.8 6.9 7.1
Front Rotor @ 285 RPM
6.8 6.7 6.7
Hey my name is Kevin
I'll do another test this week. They feel like they have improved.
04-22-2009, 10:53 PM
#30
Certified Mazda Tech
well since most people don't have os x i'll give you a quicker way to convert your compression for you:
A) go to google, or use their searchbar addon
B) enter the following into the search bar, replacing "COMPNUM" with a 2 digit single decimal (5.5 is used for this example) and "RPM" with your recorded RPM during the rotary test (189 is used for this example):
which would become (with 5.5 comp and 189 RPM):
C) Google will yield a calculation result, in this example it determines the answer as:
D) Take that number, round it to one decimal place. You wind up with 7.0. What this does is convert it to the spec RPM of 250. so at 250rpm your compression number is 7.0, which is dead on the spec. Anything below 7.0 @ 250 rpm is below spec aka bad and/or failing.
There ya go (gonna double post as a seperate topic, feel its useful).
As far as why the dealer used a different rpm, they didn't the rpm is recorded by the compression tester, it's simply the rpm of the motor at the time of the reading. 250 is the rated spec all other rpm results need to be converted slightly to measure with. Your motor overall
Enjoy,
kevin.
A) go to google, or use their searchbar addon
B) enter the following into the search bar, replacing "COMPNUM" with a 2 digit single decimal (5.5 is used for this example) and "RPM" with your recorded RPM during the rotary test (189 is used for this example):
(COMPNUM*98.0665/1000+(-0.514*ln(RPM)+2.8411))*1000/98.0665
(5.5*98.0665/1000+(-0.514*ln(189)+2.8411))*1000/98.0665
((((5.5 * 98.0665) / 1000) + (((-0.514) * ln(189)) + 2.8411)) * 1000) / 98.0665 = 6.99737203
There ya go (gonna double post as a seperate topic, feel its useful).
As far as why the dealer used a different rpm, they didn't the rpm is recorded by the compression tester, it's simply the rpm of the motor at the time of the reading. 250 is the rated spec all other rpm results need to be converted slightly to measure with. Your motor overall
Enjoy,
kevin.
Last edited by teknics; 04-22-2009 at 11:30 PM.
04-22-2009, 11:06 PM
#31
Certified Mazda Tech
kevin.
Last edited by teknics; 04-22-2009 at 11:19 PM.
04-22-2009, 11:23 PM
#32
your results graphically as requested, btw your rpm's cranking high is a sign of your low compression, you're well under spec when converted to 250. I have seen a full 1.0 improvement after a decarb tho so there's hope that just carbon is causing the low numbers (6.8 @ 285, converts to 6.14453214 @ 250rpm, which rounds to 6.2, .8kgf/cm2 off spec):
kevin.
kevin.
04-22-2009, 11:31 PM
#33
Certified Mazda Tech
and hey at least your motor's got relatively linear compression, no one face really worst then the other, that means no "breakage" just wear. do you premix or no?
kevin.
04-22-2009, 11:31 PM
#34
Yeah, even with my updated starter also.
Olorin2, did not mean to threadjack your discussion, but this helps my ultimate decision. The dealer is just waiting on me to ask for the reman if I want it.
haha - I'm going to give a good soaking
Olorin2, did not mean to threadjack your discussion, but this helps my ultimate decision. The dealer is just waiting on me to ask for the reman if I want it.
lol hydrolock a rotary, impossible i say. at least the peri-port exhaust motors, never tried a sideport.
Last edited by Nemesis8; 04-22-2009 at 11:35 PM.
04-23-2009, 08:22 AM
#36
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04-23-2009, 09:38 AM
#38
as for them swapping out your aftermarket coils for stock, they cant. If they put them on for free they couldnt send your aftermarket units back for warranty so that won't happen, theyd have to sell you new stock coils at which point you simply say no and thats that. so much disinformation about the dealer floats around....i laughed at the coil thing out loud, like we can just give away parts....
kevin.
kevin.
So much misinformation when opinions are passed around, like a child's game.
04-23-2009, 09:48 AM
#40
your results graphically as requested, btw your rpm's cranking high is a sign of your low compression, you're well under spec when converted to 250. I have seen a full 1.0 improvement after a decarb tho so there's hope that just carbon is causing the low numbers (6.8 @ 285, converts to 6.14453214 @ 250rpm, which rounds to 6.2, .8kgf/cm2 off spec):
kevin.
kevin.
04-23-2009, 09:52 AM
#41
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I told Olorin to remove the BHR kit for a couple reasons and I don't recall theft being one of them. I probably told him to remove the kit so IT didn't become an issue with regard to the warranty. I probably also told him to remove it so as to be sure the dealer mechanic didn't **** it up by removing it before calling Hank to see WTF was up. I am not in the mood to build new plug wire sets because some dealer tech wants to mishandle things he is not aware of.
So much misinformation when opinions are passed around, like a child's game.
So much misinformation when opinions are passed around, like a child's game.
My engine may be done today!
That's okay... I may end up ordering them from you down the road sometime.
04-23-2009, 09:56 AM
#42
BTW, Kevin (teknics) and I have had some fun lately, messing with each other and sharing opinions so I am sure he understands the underlying humor in my response.
Dealers are each different in their approaches. From certain business-model perspectives this is a good thing and from others, not. The biggest problem I have is that it seems the Magnuson-Moss Act is ignored most of the time.
Dealers are each different in their approaches. From certain business-model perspectives this is a good thing and from others, not. The biggest problem I have is that it seems the Magnuson-Moss Act is ignored most of the time.
04-23-2009, 10:30 AM
#43
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Well, I'm assuming that since your car is passing the compression tests, they aren't allowed to replace your engine... even though you are having the same symptoms as the rest of us. Hope you have better luck at a different dealership. I have to say that even here, the dealerships are very inconsistent about what the will and will not replace for you.
Case in point, another member here had his car in for a motor replacement last week, and the dealer just went ahead and replaced his motor mounts and entire clutch assembly under warranty. I requested that my shop specifically inspect these items while my engine was out, and they told me they would not replace them, even though my car is still under full warranty. The shop even acknowledged I had the old style motor mounts and that there is a TSB for new ones. So, it would cost me around $1000 to replace these items, when someone else got them for free at a different dealership. I don't think I'm just entitled to free stuff, but I wonder why there is so much inconsistency with the dealerships.
Good luck with your engine man... I know it's a frustrating thing trying to deal with Mazda.
Case in point, another member here had his car in for a motor replacement last week, and the dealer just went ahead and replaced his motor mounts and entire clutch assembly under warranty. I requested that my shop specifically inspect these items while my engine was out, and they told me they would not replace them, even though my car is still under full warranty. The shop even acknowledged I had the old style motor mounts and that there is a TSB for new ones. So, it would cost me around $1000 to replace these items, when someone else got them for free at a different dealership. I don't think I'm just entitled to free stuff, but I wonder why there is so much inconsistency with the dealerships.
Good luck with your engine man... I know it's a frustrating thing trying to deal with Mazda.
Matter of fact, last time I asked, they didn't know what the ZoomZoom Engine Cleaner is...
Everytime I bring with me a printed copy of TSB and show it to them they refuse to do the job since they've never seen this bulletin before.
It seems that Mazda Canada is a complete separate cluless company.
Can I drive my car to the States and have it fixed over there under warranty?
04-24-2009, 01:11 AM
#44
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04-24-2009, 11:34 AM
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04-24-2009, 06:08 PM
#46
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kevin.
04-25-2009, 10:31 PM
#47
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Okay, so the new engine is in, and so far everything is running well. It feels identical to the old one, but one thing I did notice was that the idle is now rock-steady and there is no vibration at all. The idle improved when I installed the BHR coils, but there was still quite a bit of vibration.
On my receipt from the dealer, it states that I requested that they inspect the engine mounts. The service manager initially told me that they looked fine and so they wouldn't be replaced. However, the invoice says "COMP REPLACED MNTS" under the inspection note. So it seems that they may have indeed replaced the mounts, which could account for improvement in idle vibration. Neither the tech or service manager were there to talk to today when I picked up the car. But, I'm taking the car back next week for a replacement hose that was damaged during the install, so I will ask them about the mounts.
Along the same lines, I was told that they did not replace the spark plugs, because Mazda didn't cover the plugs for an engine replacement. I found this a little surprising, but whatever. On the invoice, however, it states "SPARK PLUG SET". So again, did they replace this item? I love guessing games! The plugs in the original engine were only a couple hundred miles old, so I didn't really mind too much that they were re-using them. But I would definitely like to know for sure if they were replaced, or not!
Oh and btw, does anyone know what this part is: FEMJ-13-758 JOINT, AIR HOSE. This was one of the things replaced along with the engine.
Thanks!
On my receipt from the dealer, it states that I requested that they inspect the engine mounts. The service manager initially told me that they looked fine and so they wouldn't be replaced. However, the invoice says "COMP REPLACED MNTS" under the inspection note. So it seems that they may have indeed replaced the mounts, which could account for improvement in idle vibration. Neither the tech or service manager were there to talk to today when I picked up the car. But, I'm taking the car back next week for a replacement hose that was damaged during the install, so I will ask them about the mounts.
Along the same lines, I was told that they did not replace the spark plugs, because Mazda didn't cover the plugs for an engine replacement. I found this a little surprising, but whatever. On the invoice, however, it states "SPARK PLUG SET". So again, did they replace this item? I love guessing games! The plugs in the original engine were only a couple hundred miles old, so I didn't really mind too much that they were re-using them. But I would definitely like to know for sure if they were replaced, or not!
Oh and btw, does anyone know what this part is: FEMJ-13-758 JOINT, AIR HOSE. This was one of the things replaced along with the engine.
Thanks!
04-25-2009, 11:55 PM
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dbarber
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07-25-2015 01:34 PM
composition, compression, dirreza, dual, dunlop, engine, engines, measurement, remanned, replacement, rx8, rx8club, specs, star, x100kpa
