Brand New Engine Toast
Hey all,
I'm in a situation where a engine was bought and installed by a shop, they ordered it brand new from Mazda. I broke it in for about 2000k miles and the limiter was set at 4.5k the whole time. I brought it back for the final tune. After picking it up from the tuner/ installer, I was able to drive it 45 min before it lost power. The car was on the highway doing 80 in 4th when I accelerated and at 100 it just lost power. I was around maybe 6.5k rpm? I limped it back to the installer and he tore it apart. I'm not super knowledgeable about rotary's. He is saying that the edge of the rotor hit the housing and it needs a new rotor and housing, and that the tune they did or the install had nothing to do with that. He is stating that's common of a missed shift / over rev with the Power FCs. They set the rev limiter to 7.5k, which I don't know if that matters. It has been over 1 year since they ordered the engine so I'm out of luck with Mazda. He is saying he will pay for labor, but I would have to buy the parts. Is this scenario reasonable? I'm reaching out to see if the edge of the rotor hitting the iron is indicative of that. I'm not going to say the shop, they have been accommodating, I'm really looking for knowledge If that is a common cause for a big failure like that. |
Let's see pics of the damage.
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Originally Posted by GoodfellaFD3S
(Post 12546260)
Let's see pics of the damage.
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Sorry to hear about the motor.
Care to share what shop? |
Originally Posted by estevan62274
(Post 12546262)
Sorry to hear about the motor.
Care to share what shop? |
What modifications?
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Originally Posted by Narfle
(Post 12546265)
What modifications?
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Need more info of course but...Post pics of your setup. Also, How old is that harness? Those harnesses had problems in the past.
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Sounds like a bad tune and it sounds like the shop doesnt know what they are doing
how old was the fuel in the car? the edge of the rotor touched the housing and because of that you need a new rotor and a housing? Wtf … over revved and it is common with the pfc? these moronic excuses are a huge red flag and it sounds like you got screwed |
100% agree w R-R-Rx7
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Originally Posted by silverTRD
(Post 12546271)
Need more info of course but...Post pics of your setup. Also, How old is that harness? Those harnesses had problems in the past.
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Originally Posted by R-R-Rx7
(Post 12546272)
Sounds like a bad tune and it sounds like the shop doesnt know what they are doing
how old was the fuel in the car? the edge of the rotor touched the housing and because of that you need a new rotor and a housing? Wtf … over revved and it is common with the pfc? these moronic excuses are a huge red flag and it sounds like you got screwed I'm not super knowledgeable about rotary's and did the homework to get by most of problems I faced. Im looking to your guys knowledge on this front with the way the casualty happened. |
Originally Posted by Howard Coleman
(Post 12546273)
100% agree w R-R-Rx7
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Unless you rev'ed the engine to 10,000 rpm, rotors should not be hitting housings. This was a new engine? As in, new bearings? Did the shop verify endplay? What kind of oil were you running, and you verified the level was correct?
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Originally Posted by GoodfellaFD3S
(Post 12546280)
Unless you rev'ed the engine to 10,000 rpm, rotors should not be hitting housings. This was a new engine? As in, new bearings? Did the shop verify endplay? What kind of oil were you running, and you verified the level was correct?
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Do you have a wideband o2 so that you can quantify how rich the car was running?
I've torn down many reman and new Mazda engines over the years for street porting and other performance work and the side seal to corner seal clearance is typically too loose, which will lead to excessive fuel dilution in the oil. |
Originally Posted by GoodfellaFD3S
(Post 12546287)
Do you have a wideband o2 so that you can quantify how rich the car was running?
I've torn down many reman and new Mazda engines over the years for street porting and other performance work and the side seal to corner seal clearance is typically too loose, which will lead to excessive fuel dilution in the oil. |
Originally Posted by GoodfellaFD3S
(Post 12546287)
Do you have a wideband o2 so that you can quantify how rich the car was running?
I've torn down many reman and new Mazda engines over the years for street porting and other performance work and the side seal to corner seal clearance is typically too loose, which will lead to excessive fuel dilution in the oil. thats an issue for the long run. Not blow up the engine 45 minutes later. and since this is brought up i have over revved my engine way past the 11k-12k rpm and I haven’t had this “common outcome” even with the power fc. (Glorious moneyshifts during my more active track/racing years lol). i have been lucky i am not going to deny that. i am not saying that it can’t happen but i have seen these results with a simple case a bad tune and with a slight benefit of the doubt, with old fuel in the car but the engine was broken in for 2k miles so its not that This is a classic case of detonation where the tuner is probably a piston engine tuner and possibly inexperienced with tuning of the rotary engine. I havent even seen the tune but i am willing to bet that given the information from the OP thats what it is |
Originally Posted by R-R-Rx7
(Post 12546293)
Rich
thats an issue for the long run. Not blow up the engine 45 minutes later. and since this is brought up i have over revved my engine way past the 11k-12k rpm and I haven’t had this “common outcome” even with the power fc. (Glorious moneyshifts during my more active track/racing years lol). i have been lucky i am not going to deny that. This is a classic case of detonation where the tuner is probably a piston engine tuner and possibly inexperienced with tuning of the rotary engine. I havent even seen the tune but i am willing to bet that given the information from the OP thats what it is Understandable guess given the information I provided. I can say that the shop I'm referring too only works on rotarys. Something I did not mention earlier was that the shop did not tune the car themselves, but had a remote tuner, who has a great history tuning these cars. |
The motor should be easily broken in well before a few hundred miles, let alone 2K miles. For future reference: You also don't want long periods of time cruising at a given rpm. You want to always vary the load from accelerating and declarating.
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It sounds more like you found a spot in the map that wasn't tuned right, i.e. a condition of load/rpm/boost that hadn't been encountered and addressed during whatever tuning they did, or a hickup in fuel pressure, and pop goes the weasle.
The new rotor and housing is for the damage a broken seal caused, and covering the labor intended to keep you from asking too many questions or talking about it. |
Originally Posted by Howard Coleman
(Post 12546273)
100% agree w R-R-Rx7
This ^^. Also, when you purchase a brand new shortblock from mazda they come with a 1 year / 12k miles warranty. I verified this with my account at Mazda. Not sure why the shop tore it down rather than just simply getting a replacement sent ( I understand they were on backorder forever ). If I were you I would see about a replacement under their warranty and find another shop that is rotary specific tuning. ~ GW. |
Hey all,
Thanks for the guidance on this situation. I was able to get the pics by the builder/installer. It seems valid on what I see but I would love you all to let me know what you have seen after a failure like this. Here are pics below: https://cimg9.ibsrv.net/gimg/www.rx7...3dcdc6910e.jpg https://cimg0.ibsrv.net/gimg/www.rx7...4326891424.jpg https://cimg1.ibsrv.net/gimg/www.rx7...b5a0721e1d.jpg https://cimg2.ibsrv.net/gimg/www.rx7...613b73a343.jpg |
They broke an apex seal tuning it and handed ot back to you where it came apart enough to slow you down 45 min later.
When it ran rich and sounded like a bridgeport the engine was already blown, just didnt have the collateral damage of running a blown engine yet. Proof is in the pics. |
Are those dents in the rotor face right next to the pocket?
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That was a brand new motor from Mazda with lightening/machining on the rotor? Did you have the new motor broken down and rebuilt with processing like that?
Definitely a broken seal, but that's one hell of a dent in the corner of the rotor. https://cimg6.ibsrv.net/gimg/www.rx7...5620ccf93e.jpg |
Good eye ptrhahn on the lightened rotor.
Wondering "now" where this NEW motor came from.....who bought the motor and from whom, the car owner or the shop? |
so much here...
first off, i would like to see pics of the rotor housings which will tell me if it was a new block. the motor did NOT fail because it was overrevved. it failed due to a bad tune and it failed right where it should have around max load. in 4th gear above 6000 timing should be low. the revs aren't building fast around 100 mph and heat is cumulatively building. (perhaps) the addition of a V mount was the daggar. V mounts, stock ports, and stock turbos are a dangerous combo. to put it as charitably as i can, the tune needs to be way diff than w an OE or close to OE IC. not saying it can't be done but everything must be really set to fit w the greatly increased flow. what apex seals were in the motor. from the looks of the damage it appears they were OE. the initial impression on the rotor is an imprint of the broken tip and the following trail is where it was dragged across the rotor. the tremendous radial force flexed the crank a bit so the other side of the rotor momentarily touched the housing. rotors with intact apex seals don't touch housings. perhaps above 10,000 but even then generally not. if the rotor touched the housing it was because of the displacement by the broken apex seal. the broken apex seal IS the problem and the rotor/housing story is immaterial. (as in smokescreen) the bent tip of the rotor looks like someone DROPPED it. rotors don't get bent that way in a motor. i see no mention of AI???? this is a rotary shop sending you out w a V mount and no AI? just so you know, AI prevents most detonation. do you have a Datalogit onboard? no AFR system? what plugs? have the shop send you the PFC map in your ECU. post the file on this thread or send it to me at howracer@gmail.com you are a long way from solving your problems but fortunately the community can make the trip easier for you. |
Originally Posted by Howard Coleman
(Post 12546690)
so much here...
the bent tip of the rotor looks like someone DROPPED it. rotors don't get bent that way in a motor. . I was thinking that—I'm wondering if they went in dented, and that compromised the apex seal and caused it to break where it did. |
+1 for bad tune.
You have to remember too that Mazda engines are built to a spec so that back when these engines were new, some potential customer could go WOT to red line on a test drive without it flying apart, when on the very conservative stock tune with stock hardware. I'm not saying that's ideal for the engine, but give Mazda credit. In fact the guys who built this motor are doing low volume builds. They're probably taking more care than the original engines which lasted anywhere from 50 to 100+ thousand miles and were produced at much higher volumes. |
20 bucks says I can name the shop.
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Originally Posted by evo_koa
(Post 12546803)
20 bucks says I can name the shop.
Prolly time for someone to name names. |
I agree
Originally Posted by ptrhahn
(Post 12546837)
Prolly time for someone to name names.
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Originally Posted by R-R-Rx7
(Post 12546272)
Sounds like a bad tune and it sounds like the shop doesnt know what they are doing
how old was the fuel in the car? the edge of the rotor touched the housing and because of that you need a new rotor and a housing? Wtf … over revved and it is common with the pfc? these moronic excuses are a huge red flag and it sounds like you got screwed |
Did you get your car fixed?
Are you still waiting on your car to be fixed?
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Not sure if this is allowed or not, but I have a 90 FC with 82K on it. The car is in damn good condition, runs just fine and I do know that, sooner or later, I will need a rebuild. I also know I am not the guy to do it and that I will need someone I can trust to do it. What I am also sure of, is that I would much rather have a brand new (not remanufactured or rebuilt) engine rather than going the rebuild route. I read about ordering directly from Mazda, but I cannot find where to do this? Is there a direct Mazda link to get started? I am not looking to supersize this motor, race this car, etc. I just want a new motor that I can drop in my car when need be. If there are options which make it more reliable/stronger, then I would be willing to pay those extras.
Because I will have the money in the not too distant future, I would like to order it and have it on hand; hopefully I wouldn't have to use it right away and I get many more thousands of miles before I need to R2. Whatever the case, does anyone know where I might purchase a brand new engine? Or how to direct order one from Japan? Thanks up front for any suggestions. |
Originally Posted by evo_koa
(Post 12546803)
20 bucks says I can name the shop.
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How about downloading your PFC map and sending it to one of us who are very PFC experienced.
We can look at it for bad programming. Would also need a complete list of engine and peripheral mods. cewrx7r1@yahoo.com |
Update
Hey all, Just wanted to let you all on an update and possible method moving forward. The Shop admitted to not assessing the boost creep correctly and that is what ultimately led to detonation. They were willing to attempt to make it right. They rebuilt the rotary and reinstalled all on thier dime. They then attempted to fix the boost creep. They ported the stock twins and reinstalled a high-performance cat and were still unsuccessful at eliminating the boost creep. It seemed they were out of ideas moving forward and stalled out on the car for the past 8 months, moving onto other projects. After waiting all this time we told them to package up the car and we would take it back as is. The car is limited to 5k from the PFC for safety. What's the next step if we want to get her boost creep issue fixed? Again these are Brand new 99 Spec twins, and the setup in non-sequential. Outside of selling those twins and getting a single turbo and installing an external wastegate, what would you all recommend? While I don't agree with them not finishing the job, I'm sure we all have been in these types of wait-it-out scenarios, the shop had more time than we did unfortunately.
Looking for direction here, but again i would like to keep the privacy of the shop. Matt |
Confirmation????
This was a brand new Mazda crate motor?? |
Engine
I asked the builder and he bought the motor from Mazdatrix. I agree they do looked lightened. Calling Mazda Trix, with estimated time the builder bought it to see if he purchased a rebuilt or new motor.
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What boost controller is being used? That's likely the easiest of all the tuning problems to deal with especially with the twins. What methods were being used?
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It is unlikely you got a factory built reman. More likely is that they rebuilt the engine with parts that were hopefully in spec - which is probably the best that you can expect given the cost of new engines these days. Whats done is done. Moving on...
Regarding the boost creep, what is the boost creeping to? At what RPM? On my car, running a DP, RX7.com Bonez high flow cat, RB cat-back exhaust, vmount, small port, and an old Greddy Profec B and PFC, I was able to control boost to 10 PSI. The boost controller was the final thing that made boost control successful. The PFC running the stock boost control solenoids was not sufficient to control boost. I'd recommend starting with a boost controller. If that doesn't work, consider a restrictor plate in the exhaust. |
Originally Posted by Matthew Smith
(Post 12587106)
Brand new 99 Spec twins, and the setup in non-sequential.
Was this your direction or the shop recommendation? Seems like an odd choice unless you live in California and really hate the secondary transition. Or the shop can't make the sequential system work. |
Sorry to say but I personally think you’re wasting your time and money into this shop. I’d say you try and get as much money as you can get back and take it to a shop you can trust. Some shops are very cool and make ya feel comfortable, but I don’t see them producing results for you. Now they are going to try and rebuild your motor and get it running as cheaply as possible. If they do that. I would at the very least have someone else tune it. If they knew there was boost creep issues they should have not let you take the car and say it was fine to go wot.
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