"Offerup/letgo" $140 dressed mystery motor teardown & rebuild
07-11-2018, 12:52 PM
#1
"Offerup/letgo" $140 dressed mystery motor teardown & rebuild
Hello everyone,
The primary purpose of this thread is to document the teardown and rebuild of this motor, sharing that with the forum as well as asking advice as needed. This teardown will be documented with pictures and videos, posts made as progress is made. Pictures and videos will primarily be taken using my phone, so please forgive if some of the pictures are less than perfect quality and clarity.
Pictures, videos, and details to come, thank you for reading.
-Ricky
The primary purpose of this thread is to document the teardown and rebuild of this motor, sharing that with the forum as well as asking advice as needed. This teardown will be documented with pictures and videos, posts made as progress is made. Pictures and videos will primarily be taken using my phone, so please forgive if some of the pictures are less than perfect quality and clarity.
Pictures, videos, and details to come, thank you for reading.
-Ricky
07-11-2018, 01:30 PM
#2
In the last several months the overall performance of my Rx8 has started to decline, and considering that I have stayed on top of all my regular maintenance and services on the vehicle I knew it could only be one culprit: compression loss. Upon testing my compression, I became aware my numbers were so low that they were not even on Mazda’s official compression passing/failing chart. I knew it was time to prepare for the replacement of the motor. Unfortunately, my finances had drastically changed and the option of purchasing a reman became out of reach.
At that point I decided I would be rebuilding the motor myself. I had all the tools needed to rebuild the motor, minus a few specialty tools I needed to order such as a flywheel stopper, 54mm socket, and engine stand adapter just to name a few. I do not own any specialty tools to check and assess things such as step wear or other tolerance measurement devices for my core engine components so I will be getting the core components evaluated and assessed by either Mazdatrix or Racing beat when the time comes for that.
I began researching to prepare myself to rebuild my motor, as well as searching for the tools required for the rebuild process that I lacked at that point in time. While searching, I came across a listing on both offer up and letgo regarding an Rx8 that was being parted out due to the owner planning to do an LS1 swap. After contacting the owner he informed me he had purchased the car out of town down in Los Angeles (I am in Bakersfield for reference), and that the vehicle was not running when he purchased it. He informed me the previous owner claimed that they rebuilt the engine recently, however it had “lost a front apex seal” though the current owner could not confirm that claim nor did the current owner even attempt to start the engine. I asked him how much he wanted for the engine and he responded asking $100. I thought maybe it was a mistake, so I asked him to verify that is how much he wanted for the motor as well as how much he wanted for the motor completely dressed. He followed up with $140 dressed so obviously without second thought I went and immediately purchased the engine from him because why not? Just inspare parts alone it was a steal even if the motor was completely trashed internally.
At that point I decided I would be rebuilding the motor myself. I had all the tools needed to rebuild the motor, minus a few specialty tools I needed to order such as a flywheel stopper, 54mm socket, and engine stand adapter just to name a few. I do not own any specialty tools to check and assess things such as step wear or other tolerance measurement devices for my core engine components so I will be getting the core components evaluated and assessed by either Mazdatrix or Racing beat when the time comes for that.
I began researching to prepare myself to rebuild my motor, as well as searching for the tools required for the rebuild process that I lacked at that point in time. While searching, I came across a listing on both offer up and letgo regarding an Rx8 that was being parted out due to the owner planning to do an LS1 swap. After contacting the owner he informed me he had purchased the car out of town down in Los Angeles (I am in Bakersfield for reference), and that the vehicle was not running when he purchased it. He informed me the previous owner claimed that they rebuilt the engine recently, however it had “lost a front apex seal” though the current owner could not confirm that claim nor did the current owner even attempt to start the engine. I asked him how much he wanted for the engine and he responded asking $100. I thought maybe it was a mistake, so I asked him to verify that is how much he wanted for the motor as well as how much he wanted for the motor completely dressed. He followed up with $140 dressed so obviously without second thought I went and immediately purchased the engine from him because why not? Just inspare parts alone it was a steal even if the motor was completely trashed internally.
Last edited by Ricky SE3P; 07-11-2018 at 01:53 PM.
07-11-2018, 01:52 PM
#3
Upon getting the engine home the first thing I did was pull the spark plugs. The leading plugs looked relatively clean however the trailing plugs appear to have seen better days. The paint looked relatively fresh however it was obvious the motor had been sitting for an extended period of time, at least a few months. Removing the pressure plate revealed and confirmed the clutch assembly to be relatively new and likely reuseable. I havent been able to identify a brand for the clutch kit, but the quality appears to be good but if anyone can properly identify the brand please chime in. Flywheel looks nearly new, definitely reuseable. Rear main seal looks very new, and I noticed that the tension bolts are numbered which was intruguing. No idea who wouldve done that, all builders local to the LA area have denied it to be their handywork. Thermostat and thermostat housing look to be in really rough shape, not sure what wouldve caused the corrosion, there was FL22 coolant in the system. Definitely negligence on the builder/owners part for not having checked or addressed that at time of rebuild. Hopefully opening it up the motor looks alright. I will attempt to clean and free the thermostat housing of rust, but I may just trash it and source another.
07-11-2018, 02:00 PM
#4
Water pump appeared to be brand new which I was very happy to find, another new part to use for the rebuild and save some money. The motor and my findings are excellent so far minus the thermostat and thermostat housing discovery. Time to strip the motor down and get it on the stand. Tearing down the motor there are some parts that are either damaged or in such poor shape I threw them away immediately, such as the engine wiring harness and coolant lines. I got the motor on the stand, I removed the oil pan and what I saw left me with mixed emotions. Assuming it didn't get there during disassembly and tossing and turning the motor several times, it almost looks like there is a milky-ish tint in the oil pan. I suspect this motor may have overheated and lost a coolant seal, or maybe I'm lucky and a seal was just pinched during re-assembly resulting in a very minor leak. Either way I am confused about my findings thus far. Removing the oil pickup and looking briefly at the housings and irons from that angle, the housings appear to be somewhat new looking, or at the very least possibly had been cleaned very well. Or maybe its all in my head and they look normal, who knows. Got the front hub bolt out and front cover off. OEM thermal pellet here, don't notice anything abnormal yet, at least nothing specific that has caught my attention. Thought it was interesting to find grey RTV on the front hub bolt, cant say I've ever noticed that before.
07-11-2018, 04:53 PM
#7
How'd you find that info? I wasn't aware I could track some parts using labeled or etched information. Or concluding based on front cover reman plate? Just curious. We will know the inside soon (just gotta make the time to break it down the rest of the way)
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NotAPreppie (07-12-2018)
07-11-2018, 05:26 PM
#9
Yeah i recognise the reman tag on the front cover, i just didnt know if theres a way to use any of the engraved information on the housing itself to identify if the housings on this motor were the same housings used when that reman was built, or if whoever rebuilt this engine just so happened to reuse a front cover that had that reman tag on it and they are not the housings supplied with that reman.
07-11-2018, 05:58 PM
#10
Administrator
iTrader: (7)
excellent thread Xero, looking forward to what you find in the motor.
07-12-2018, 06:39 AM
#13
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Yeah i recognise the reman tag on the front cover, i just didnt know if theres a way to use any of the engraved information on the housing itself to identify if the housings on this motor were the same housings used when that reman was built, or if whoever rebuilt this engine just so happened to reuse a front cover that had that reman tag on it and they are not the housings supplied with that reman.
07-12-2018, 10:03 AM
#14
Did not make much progress last night unfortunately, and lost a couple seals that went flying the second I moved the rotor to remove it (just my luck). Also found some damage, I think the e-shaft might be trash along with a few bearings and other parts. I am starting to lean towards the idea of oil starvation/lack of lubrication in some areas causing the damage. Will post pictures and commentary shortly
07-12-2018, 12:29 PM
#16
Picking up where I left off in my last update;
First needle bearing looks pretty good actually, the plate beneath it seems to have some differences in coloration which lead me to believe that the area may have been seeing lack of lubrication from lack of pressure or possibly even oil starvation? Inspecting the needle bearing looked pretty good overall. The sleeve looks to have several gouges in it and to my memory it is supposed to be completely uniform so that is damaged and needs to be replaced. Not sure if the damage to this piece caused any additional engine damage elsewhere. Removing the 6 bolts and inspecting the rear of the plate reveal what I would describe as significant damage to the plate as well as the needle bearing beneath it. None of those components would be salvageable and need to be replaced. Hopefully that is not expensive as I have never search for replacements of those components
First needle bearing looks pretty good actually, the plate beneath it seems to have some differences in coloration which lead me to believe that the area may have been seeing lack of lubrication from lack of pressure or possibly even oil starvation? Inspecting the needle bearing looked pretty good overall. The sleeve looks to have several gouges in it and to my memory it is supposed to be completely uniform so that is damaged and needs to be replaced. Not sure if the damage to this piece caused any additional engine damage elsewhere. Removing the 6 bolts and inspecting the rear of the plate reveal what I would describe as significant damage to the plate as well as the needle bearing beneath it. None of those components would be salvageable and need to be replaced. Hopefully that is not expensive as I have never search for replacements of those components
07-12-2018, 12:39 PM
#17
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If you haven't already, you should look into getting a membership with Mazda Motorsports Development. Parts at wholesale prices are hard to complain about.
07-12-2018, 12:50 PM
#18
Removing the rear iron reveals a lot of great news with (at least thus far) very minimal bad news. From my initial observation and inspection, the rear iron looks excellent. No pitting or scratches in the iron surface, this component appears to be definitely reusable. A quick glance at the rotor and rest of the engine reveal what appears to be entirely intact seals and no initially visible or apparent damage. Heck, I would even go as far as to say this motor was barely used or ran post-rebuild. Everything appears to be in fantastic, nearly new shape. Dare I say some seals be reusable as well? Hmm.
That aside, this teardown isn't all cupcakes and rainbows. Taking a closer look at the rear stationary gear reveals the first sign of something having gone very wrong, exposed copper on the rear stationary gear bearing. I have not yet removed the rear gear to take a closer look, but just from first glance this definitely is not good. It only takes a few seconds to look at the corresponding area of the e-shaft to discover damage there as well. Improper balancing? Could we end up finding rotors that are not matched resulting in the rotating assembly being off balance? Or is this an isolated issue and just a result of poor or lack of lubrication? I suppose as the teardown continues we will find out. Sadly, it looks to me like this e-shaft is fubar'd and I need a new rear stationary gear bearing.
Removing the rear rotor this morning and taking a VERY brief (like 10 second) look at it, the rotor looks almost brand new. Hell, even the rotor bearing looks pretty good if you ask me but I am no expert nor are these pictures that great so a closer inspection is needed. Looking at little is exposed and visible of the rear housing and middle iron, they look very good! No deep scratches or pitting in the area, nor did I see any chipping or flaking of the chrome on the rotor housing. No cracks or anything worrisome around the spark plug holes, just quite a bit of grey RTV here as well it seems like. Hell it looks nearly new as well! Score!
That aside, this teardown isn't all cupcakes and rainbows. Taking a closer look at the rear stationary gear reveals the first sign of something having gone very wrong, exposed copper on the rear stationary gear bearing. I have not yet removed the rear gear to take a closer look, but just from first glance this definitely is not good. It only takes a few seconds to look at the corresponding area of the e-shaft to discover damage there as well. Improper balancing? Could we end up finding rotors that are not matched resulting in the rotating assembly being off balance? Or is this an isolated issue and just a result of poor or lack of lubrication? I suppose as the teardown continues we will find out. Sadly, it looks to me like this e-shaft is fubar'd and I need a new rear stationary gear bearing.
Removing the rear rotor this morning and taking a VERY brief (like 10 second) look at it, the rotor looks almost brand new. Hell, even the rotor bearing looks pretty good if you ask me but I am no expert nor are these pictures that great so a closer inspection is needed. Looking at little is exposed and visible of the rear housing and middle iron, they look very good! No deep scratches or pitting in the area, nor did I see any chipping or flaking of the chrome on the rotor housing. No cracks or anything worrisome around the spark plug holes, just quite a bit of grey RTV here as well it seems like. Hell it looks nearly new as well! Score!
07-12-2018, 01:29 PM
#19
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Okay, now compare those photos to what Omar Mena @ OJ Imports sent me after tearing down my <10k mile rebuild...
https://www.rx8club.com/series-i-tro...2/#post4814861
I think you may be right about this engine not having been run for a significant period of time.
https://www.rx8club.com/series-i-tro...2/#post4814861
I think you may be right about this engine not having been run for a significant period of time.
07-12-2018, 02:17 PM
#20
I was looking at the requirements and they list that you need 24mo of race results to qualify. Otherwise there is no discount on factory parts.
07-12-2018, 04:57 PM
#21
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You misread or misinterpreted that...
https://www.mazdamotorsports.com/get...am-membership/
You only need to have competed in a single SCCA or NASA autocross in the last 24 months OR be a member of the SCCA or NASA.
https://www.mazdamotorsports.com/get...am-membership/
- Be a legal resident of either the United States, Canada or Mexico (however, we currently only ship parts within the U.S.)
- Have a valid membership with a sanctioning body/organization approved by Mazda such as the Sports Car Club of America (SCCA) or the National Auto Sport Association (NASA) if you desire to compete (e.g., Track Day members do not need a membership)
- Either be building a Mazda for competition or have competed in one sanctioned event approved by Mazda within the last 24 months
07-12-2018, 05:08 PM
#22
"Building a Mazda for competition"
I am right down the road from Buttonwillow Raceway, and not too far from many other raceways. I've upgraded a good number of components on my car in prep for Auto-X and track days at Buttonwillow, so it wouldn't hurt for me to get a hold of Mazda Motorsports to apply to become a member. Especially being I have raced my last 2 Rx8's in Auto-X events in both Florida and California.
I'm currently relocating my battery to the trunk in this Rx8 the same way I did in my last one (album with pictures showing what I did in my profile)
High flow cat will be paired to Mazdaspeed catback post-rebuild.
Need to get an upgraded radiator and -want- an aluminum coolant res for reliability (no fear of cracking/failing on track)
Want BHR Ignition for all related benefits (even though current coils have only 6k miles on them)
Want Rotary compression tester to periodically check compression every 6 months.
Want header just because I want one.. lol
I am right down the road from Buttonwillow Raceway, and not too far from many other raceways. I've upgraded a good number of components on my car in prep for Auto-X and track days at Buttonwillow, so it wouldn't hurt for me to get a hold of Mazda Motorsports to apply to become a member. Especially being I have raced my last 2 Rx8's in Auto-X events in both Florida and California.
I'm currently relocating my battery to the trunk in this Rx8 the same way I did in my last one (album with pictures showing what I did in my profile)
High flow cat will be paired to Mazdaspeed catback post-rebuild.
Need to get an upgraded radiator and -want- an aluminum coolant res for reliability (no fear of cracking/failing on track)
Want BHR Ignition for all related benefits (even though current coils have only 6k miles on them)
Want Rotary compression tester to periodically check compression every 6 months.
Want header just because I want one.. lol
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Jedi54 (07-20-2018)
07-12-2018, 05:45 PM
#23
What am I doing here?
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If you can look up the results for a NASA or SCCA event that you attended in the last 2 years, you can submit that result on their website. Usually takes them a few business days to review your application.
https://store.mazdamotorsports.com/w...0001&langId=-1
https://store.mazdamotorsports.com/w...0001&langId=-1
07-12-2018, 07:00 PM
#25
That makes no difference. If you are building a car, they only need pics of your vehicle and then after you have it up and running and you get results, you can send them in. Just check their website or give them a call and they will gladly get you set up.