Brand New Engine Toast
01-18-23, 09:47 AM
#28
Racing Rotary Since 1983
iTrader: (6)
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.
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.
Last edited by Howard Coleman; 01-18-23 at 09:59 AM.
01-18-23, 10:16 AM
#30
+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.
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.
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ArmenMAxx (01-19-23)
01-20-23, 10:09 AM
#34
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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
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
03-15-23, 02:09 PM
#36
Full Member
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.
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.
03-15-23, 09:41 PM
#38
Eye In The Sky
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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
We can look at it for bad programming.
Would also need a complete list of engine and peripheral mods.
cewrx7r1@yahoo.com
12-18-23, 05:15 PM
#39
Junior Member
Thread Starter
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
Looking for direction here, but again i would like to keep the privacy of the shop.
Matt
12-19-23, 08:32 AM
#41
Junior Member
Thread Starter
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.
Last edited by Matthew Smith; 12-19-23 at 08:41 AM.
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gracer7-rx7 (12-19-23)
12-19-23, 12:00 PM
#43
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.
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.
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Speed of light (12-20-23)
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boostin13b (12-20-23)
12-19-23, 09:03 PM
#45
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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