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I just had my car tuned on the dyno and 2 days later the car wouldn't start after doing some back to back street pulls. I broke the engine in for 1k miles and lost compression after 1178 miles. I took the motor out this past weekend and have disassembled it. Just wanted to post here to add to the internet information collections.
The motor consisted of the following parts:
-Brand New S5 Front, Center, and Rear Irons W/ Stock Ports (Idle so smooth)
-Brand New S6 Housings, Both are Fronts if anyone is interested
-Used S5 Turbo Rotors (From Previous Engine W/ counterweight and Flywheel)
-Brand New RX8 Eshaft
-FD Side Seal and Corner Seal Springs
-Mazda Side Seals
-Atkins Solid Corner Seals W/ Raised Edge
- E and J Apex Seals
-Mazda Apex Seal Springs
-OEM Oil Control Rings, Coolant, etc
-Mazda Side Seal Clearance Spec
-New Thrust Components
-Mazda Spec End Play
-BUR9EQ Plugs
Car part list(At the time):
-Adaptronic S4 PNP ECU
-New Wiring Harness (Made by me with new ECU Connectors and Pins)
-ID 1050X Primary and Secondary
-PTFE Fuel Lines W/ Parallel Fuel Delivery to Rails
-IGN1A Coils 2 Per 40 Amp Relay
-500CC W/M Injection with Boost as Reference
-DC Power 180 Amp Alternator
-No PS/AC/Air Pump
-CX Racing Thick Wall Manifold (My Demise)
-Generic HKS 44/40MM Wastegate ("")
-Holset HX40 69MM T4 Turbo
-Large FMIC
-Aluminium Radiator
-Black Magic EFan
-Walbro 450 Fuel Pump
-Aeromotive Fuel Filter
-Aeromotive FPR
-Premix 2oz Per Gallon Idemitsu
From my initial inspections the rear rotor apex seals all warped and are about .1mm shorter in the middle of the apex seal. See attached pictures if they actually attached. I believe this was due to the EGTs getting too high as well as the exhaust back pressure. During the dyno pulls the manifold would glow bright red. The car made 350 WHP and 300 LB/Ft. The boost was set around 11 psi but at around 5800 RPM the boost would creep all the way to 17 psi at 7600 RPM. 2 nights later after doing some back to back pulls on the street I pulled off to check the car as I always do after giving it some good load and I did the hood check and everything smelled and looked fine but the idle did sound off. Next morning I go to start it and I can hear the dead rotor.
A question I have for you all is in the pictures that hopefully attached you can see the iron is stained a dark brown color on the running surface in the combustion area only on both the front and rear rotor. What is this a sign of?
I have no bad words for the apex seals as they didn't seem to hurt anything too bad in the motor but I was only able to run it for a short period of time. My plan is to change to a Turblown Cast manifold with the dual 40MM gates to alleviate the exhaust backpressure/heat issue and try my luck again. Also some EGT gauges
Lastly as per recommendation of my engine tuner I will be going with RA Classic apex seals with OEM springs. Hopefully I can get the engine rebuilt and in the car in the coming weeks
Thank you,
Mike
Last edited by Michael Mansour; 02-27-23 at 03:42 PM.
After Measuring a brand new Atkins Apex seal (ones I had lying around the garage) They are 8mm in height which I know is the standard. Measuring the E and J seals they are at 7.5mm on the front rotor apex seals (front rotor had compression averaging 105).
The seals lost .5mm after 1178 miles which is wildly concerning. I believe I misspoke earlier when I said the rear rotor apex seals warped, they simply wore in the centers where it experienced the most heat. After looking at the measurements, I no longer am happy with my choice of E and J seals. They wouldn't have lasted in any world and I was hoping that the motor would be able to do at least 50k miles lol. Hopefully with the additional hardness from the RA seals the motor can experience a long life.
Pictures of New Atkins Seal height vs the 1178 mile E and J:
unfortunately a chain is as strong as it's weakest link. your "warped apex seals" are not the cause but the result of the weak links. FWIW i like E&J seals.
a look at your rotor housings shows the tell tale carbon flanking your plug bosses. i would also like to see the close area of your exhaust ports. given you almost melted your tubo manifold there had to be lots of lift of your seals in that area. you can see the resultant chatter marks showing your apex seals bouncing after being pushed back into their grooves by spark plug mountain and, wait for it, "exhaust close ridge." going forward ECR
while i am not familiar w the Holset H40 a quick check shows it to be a 62 mm inducer not 69. big diff. it appears it is a 70 lb per minute turbo as they quote max piston power of 700. also .53 kg/s which translates to 70 pounds per minute.. about 525 max rw rotor hp.
it has a pretty good size hot side wheel. i don't think your turbo is the problem.
either your timing, AFRs or your turbo manifold/wastegate/exhaust are the culprit and your apex seals paid the price.
as an aside... w re to apex seals wearing. yes you can measure them but often you can just feel the edge of the crown. if they are worn the metal doesn't vanish, it is moved off the crown and ends up as a ledge. you can often shave with them. do yours have a sharp edge?
getting back to weak links... what are 9s doing in the motor? one of the most effective ways to lower SPM and ECR is run cold plugs. i am running 11s in all four positions. spark plugs are really important to get right. you have the right coils to fire cold plugs. the colder the plug the less wear on the apex seal.
check your ECU as to Deceleration Fuel Cut. if it is "on" this would be a culprit. the motor needs fuel/premix at all times while rotating. given the color on your manifold i would be looking for for a flow restricition on the exhaust side.
i do like your moving on from the manifold which doesn't appear to offer enough WG. (creep from 11 to 17), 2 44s rather than 2 40s if you can... what is the I D of the manifold runners on your current manifold? can you post a pic of your engine bay?
Last edited by Howard Coleman; 02-27-23 at 05:54 PM.
unfortunately a chain is as strong as it's weakest link. your "warped apex seals" are not the cause but the result of the weak links. FWIW i like E&J seals.
a look at your rotor housings shows the tell tale carbon flanking your plug bosses. i would also like to see the close area of your exhaust ports. given you almost melted your tubo manifold there had to be lots of lift of your seals in that area. you can see the resultant chatter marks showing your apex seals bouncing after being pushed back into their grooves by spark plug mountain and, wait for it, "exhaust close ridge." going forward ECR
while i am not familiar w the Holset H40 a quick check shows it to be a 62 mm inducer not 69. big diff. it appears it is a 70 lb per minute turbo as they quote max piston power of 700. also .53 kg/s which translates to 70 pounds per minute.. about 525 max rw rotor hp.
it has a pretty good size hot side wheel. i don't think your turbo is the problem.
either your timing, AFRs or your turbo manifold/wastegate/exhaust are the culprit and your apex seals paid the price.
as an aside... w re to apex seals wearing. yes you can measure them but often you can just feel the edge of the crown. if they are worn the metal doesn't vanish, it is moved off the crown and ends up as a ledge. you can often shave with them. do yours have a sharp edge?
getting back to weak links... what are 9s doing in the motor? one of the most effective ways to lower SPM and ECR is run cold plugs. i am running 11s in all four positions. spark plugs are really important to get right. you have the right coils to fire cold plugs. the colder the plug the less wear on the apex seal.
check your ECU as to Deceleration Fuel Cut. if it is "on" this would be a culprit. the motor needs fuel/premix at all times while rotating. given the color on your manifold i would be looking for for a flow restricition on the exhaust side.
i do like your moving on from the manifold which doesn't appear to offer enough WG. (creep from 11 to 17), 2 44s rather than 2 40s if you can... what is the I D of the manifold runners on your current manifold? can you post a pic of your engine bay?
Howard,
Thank you for your detailed response.
Yes there is carbon buildup just above the exhaust ports as well as you mentioned.
The HX40 I have has a larger modified compressor wheel and was rated by the turbo builder for 900 piston hp. I believe the single 40mm gate is just not enough especially with its very low priority in exhaust flow.
The edge of the front rotor apex seals are sharp and feel as i have felt before. On the rear rotor apex seals they feel knurled on their edges and are quite rough. This I noticed during disassembly.
I do have some NGK R7420-10 that I was planning on switching to...on this next iteration I will switch to them before the car sees any sort of boost. I have read your updated spark plug postings and those new ones sure do look interesting but not yet ill stick to the 7420s for a while till you test them some more.
I have fuel going into the motor on decel and keep it in the 13s-14s AFR on decel.
I am hoping that with a manifold that prioritizes wastegate flow better and having more wastegate surface area I will be able to evacuate the hot air from the engine enough to support the 450 whp goal for a significant period of time.
Picture is when it was almost running but missing some clamps and such:
Hmmm, our situations are all too similar, except I used RA Superseals and have switched to E&J lol. Honestly your rotor housing looks a heck of a lot better than mine did, which is likely due to the softer E&J seals over my harder RA Superseals....food for thought. We have nearly identical mileage also.
My car is also running an Adaptronic ECU, I was also using BUR9's and my manifold has a similar shape to yours except it is IWG (rear runner is longer than front runner). I am using an EFR9174 turbo. Are you using Ryan to tune? I know he likes the superseals is why I ask but is also who is tuning my car.
Hmmm, our situations are all too similar, except I used RA Superseals and have switched to E&J lol. Honestly your rotor housing looks a heck of a lot better than mine did, which is likely due to the softer E&J seals over my harder RA Superseals....food for thought. We have nearly identical mileage also.
My car is also running an Adaptronic ECU, I was also using BUR9's and my manifold has a similar shape to yours except it is IWG (rear runner is longer than front runner). I am using an EFR9174 turbo. Are you using Ryan to tune? I know he likes the superseals is why I ask but is also who is tuning my car.
I did read your thread as I was researching my problem and which apex seal to use. I premixed a little bit more than you but yes my housing does look to be in much better condition. The wear of .5 mm is still out of the normal I believe on my set of E&J . I am not using Ryan to tune but I will be installing a set of the RA classics and doing all new oil control ring cages rings springs, side seals, FD springs yada yada. Over the past few days I have been cleaning and inspecting my rotors to check for proper clearances to ensure one did not pinch. Did Adam of REC mention anything to you about your rotor tip or corner seal clearances? Have you gotten your motor reassembled yet?
Hmmm, our situations are all too similar, except I used RA Superseals and have switched to E&J lol. Honestly your rotor housing looks a heck of a lot better than mine did, which is likely due to the softer E&J seals over my harder RA Superseals....food for thought. We have nearly identical mileage also.
My car is also running an Adaptronic ECU, I was also using BUR9's and my manifold has a similar shape to yours except it is IWG (rear runner is longer than front runner). I am using an EFR9174 turbo. Are you using Ryan to tune? I know he likes the superseals is why I ask but is also who is tuning my car.
After further inspection into your pictures the uneven corner seal wear as mentioned by Howard in your post is looking like the cause of concern in your situation. I have always glued my apex seal corners
I haven't reassembled yet, I'm basically ready to now, just waiting to pull the trigger on all new rotors seals, OCR's and an overhaul kit (my wife returns to work from maternity leave next week, so we'll be looking forward to having dual income again!). And yeah I can't comment too much on whether or not the assist pieces were glued or not on that engine as I didn't assemble it (but I will be building this one). I did check all my clearances on my rotors prior to even taking it to REC and corner seals were all good; rotor apex seals slots may have been slightly tight, a .003" feeler would bind the seal up but this was consistent on both front and rear so I'm not sure that explains it. Either way I will be filing these to proper clearances when I build it this time to ensure that's not an issue.
There is definitely a big difference in how my seals wore in comparison to yours, so its likely we are dealing with different causes but like yourself I have now added EGT probes to ensure I don't have one rotor running super rich and the other super lean, although there wasn't much for signs of extreme EGT's on my torn down engine. My seals were worn down .1mm on the assist piece end and 0.8mm on the opposite end of the seal!
With my limited knowledge, I'd have to say based on the amount of boost creep you were getting EGT's getting a bit too high seems like a likely candidate for you. My setup I was actually having boost fall off at higher RPMs (was hitting 15PSI and dropping to 13PSI between 7000-8500 RPM).
Either way, all I can do now is rebuilt this engine to the best of my ability and monitor everything closely (especially since I'm no longer blind on EGTs) and hope that Howard's theory is accurate and it was just a mechanical/build issue.
Anyways, looks like you have a great setup, it was spooky reading it and seeing how similar ours are! Wishing you success on this rendition of it
Last edited by RotaryMachineRx; 03-01-23 at 09:30 AM.
Glad to hear your rotors are looking good. I wish I was close to REC like you. Hopefully you can get it together soon! It looks like Ill be putting mine back together in about 2 weeks once all the parts come in.
I'm concerned that my rotors may be cause for the issue. Upon inspecting them last night I saw several things that were out of the ordinary. I will post an update here later with the findings and some pictures. New rotors are $$$$$$
We will rebuild and figure it out. It was very spooky reading your thread but your setup a lot more sexy than mine
Update with some more information dumping. I have been cleaning and inspecting the rotors and have noticed that one of my combustion pockets of my s5 rotors is no longer machined. It looks cast. See attached pictures.
I also noticed that the secondary Apex seal spring has a wider tang on the e&j and RA seals vs Atkins. E&J and RA have a 44mm gap and the Atkins is 42. Don't know what a factory one is but interesting...
I'll be reusing the rotors in the next rendition even with their small blemishes. I don't think that they look too bad
I noticed that my coolant seals had separated, this is apparently not an OEM seal but an atkins one that looks OEM. I did not have any coolant/cooling issues.
Insult to injury. This evening I was cleaning the rotor housings and I noticed these two odd grey spots on the housing coolant jacket paths. One of them was cracked and due to my concern of water jacket sealing I proceeded to push on it with an Apex seal and it chipped out. There was epoxy on my new housings?? I proceeded to clear out both spots and one of them is a massive crater. It looks like I was sold a defect part that someone attempted to repair. I will be emailing mazdatrix immediately and calling them first thing on Monday. Sadness
Last edited by Michael Mansour; 03-04-23 at 08:04 PM.
Rotor housings-
That is epoxy straight from Mazda used to fill small imperfections on brand new rotor housings.
I put pictures of the housings with that up here a while ago on my Mazda crate engine's rotor housings.
Rotors-
I dont know if that oxidization damage is from extreme heat of detonation or something else.
Your rotors look badly dented from detonation, but it might just be the lighting/reflection of rotor housing. Put a straight edge across the short side of the rotor faces. Any light shine through the middle up around the rotor tips?
while perhaps just a bit larger than the USUAL imperfections on new Mazda blocks they are not a problem. clean them out, JB Weld them and then go over the JBW w a new razor blade so that it is flat and you will have zero problems.
those are Atkins comp rings and they shouldn't be anywhere near a motor until David tunes them up. i also found the inner white ring separates a lot from the orange core. not good. also not good of Atkins to not disclose they are not OE. i am happy they are in process of providing another option but it shouldn't be marketed until it is equal to OE... or, at minimum, there should be disclosure.
do you have a small dent in the face of your rotor? if so that does not come from knock/detonation, it comes from pre-ignition. very dangerous. surface gap plugs in the trail solve that problem.
Rotors-
I dont know if that oxidization damage is from extreme heat of detonation or something else.
Your rotors look badly dented from detonation, but it might just be the lighting/reflection of rotor housing. Put a straight edge across the short side of the rotor faces. Any light shine through the middle up around the rotor tips?
detonation, thats what a piston engine looks like too. plus the rotor is dented...
Thank you all for the replys and concerns about the rotors. It was simply the reflection of the rotor housing. The rotor is not dented or deformed there in any sort of way.
I did as Howard mentioned and filled the holes with jb weld and went over them with a new razor blade. I will send pictures tomorrow when it has dried.
All new seals and springs should be here Friday, hoping to get it together sometime next week.
I was looking at the I-rotary Apex seals and they recommend a 2-2.5oz premix level....interesting
I did enjoy reading through your thread. Beautiful build you have there on your hands. I do not plan on ever running ethanol as I want the car to be as street friendly as possible. Maybe I can do some of my own limited testing with my idemitsu vs walmart vs stihl premix which is all ive ever used.
I got all of the parts in for the rebuild and I did request from Atkins OEM coolant seals but I'm having a hard time telling the difference, any input is appreciated.
i know this going to be kind of silly, but if you were at a dealership and wanted to return things to Mazda one of the qualifications is that it must have the Mazda tag on it, and not the pick ticket from Mazda USA, it needs to have the tag from Mazda Japan (which is a minor problem, as Mazda USA sometimes sells stuff they didn't get from Japan...)
a tag like this one, note the current ones are black:
the point is, without that tag on it, you are taking their word that its the Mazda part vs something else.
I did as Howard mentioned and filled the holes with jb weld and went over them with a new razor blade. I will send pictures tomorrow when it has dried.
Did you ever grab a photos of the finished product? I had my housings media blasted and found 2 spots on the same face similar to yours that need to be touched up. Other than that I measured all my housing widths last night (don't have a micrometer so settled with my Vernier caliper) and they are looking perfectly fine. Ordering my rebuild kit and all new rotor seals and springs from REC today as well.
Last edited by RotaryMachineRx; 03-10-23 at 11:15 AM.
02-27-23, 03:38 PM
