engine damage - why?
03-23-11, 11:26 AM
#1
engine damage - why?
So for the last couple of days, I thought I had flooding problems. I started the car up after 3 years after doing a whole bunch of mods to the car. The only thing that wasn't modified was the engine. It started on the first crank surprisingly. I was using a base map that another member made and modified it to have conservative timing and run really rich (11 afr). Boost was set to 9psi on the gt35r. Came the next day to start it and it wouldn't start. I thought I flooded it. After struggling to start it for a while, it finally started with some atf. Car sounded like it was running on one rotor. I pulse reved it to "free up" the apex seals. The car sounded much better. Took it for its first spin around the block to check out afr's and detect knock, and give it 70% throttle in first gear while watching the afrs and listening for knock. Everything was normal, but as soon as I slowed down, it sounded like it was running on 1 rotor and then it died. Pushed it back home and tried to start it at home. No go. Did a compression test, front rotor was missing two compression pulses. Time to take apart the engine.
This is what I discovered:
rear rotor housing damage: (can't be reused)
rear rotor has a very tiny indentation near the bowl, everything else is mint. will probably sell this.
the intermediate, rear, front housing, and eccentric shaft have pretty much no wear. will probably sell these.
front rotor housing damage: (can't be reused)
front rotor damage: (can't be reused)
during disassembly, i found out that the primary air bleed sockets, which I bought brand new and put in, were broken.
do you guys think that the airbleed sockets could have done this much damage?
on the bright side, the gt35r turbine is fine.
This is what I discovered:
rear rotor housing damage: (can't be reused)
rear rotor has a very tiny indentation near the bowl, everything else is mint. will probably sell this.
the intermediate, rear, front housing, and eccentric shaft have pretty much no wear. will probably sell these.
front rotor housing damage: (can't be reused)
front rotor damage: (can't be reused)
during disassembly, i found out that the primary air bleed sockets, which I bought brand new and put in, were broken.
do you guys think that the airbleed sockets could have done this much damage?
on the bright side, the gt35r turbine is fine.
03-23-11, 05:28 PM
#4
silver ghost
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Yes. Those plastic pieces can cause major damage. They usually get stuck in places causing things to break. It is very easy to break off pieces of the old ones and have them fall inside.
03-23-11, 05:37 PM
#5
I assume you mean turbine wheel? Garrett doesnt sell replacement parts for the gt series, but if the compressor wheel and chra are in good condition you can use Garretts exchange program and get a fresh chra for about $400. Turbos direct in AZ has the best prices and quickest turn around I know of.
03-23-11, 09:09 PM
#7
I assume you mean turbine wheel? Garrett doesnt sell replacement parts for the gt series, but if the compressor wheel and chra are in good condition you can use Garretts exchange program and get a fresh chra for about $400. Turbos direct in AZ has the best prices and quickest turn around I know of.
Yes i meant turbine wheel.
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03-24-11, 08:49 AM
#11
Racing Rotary Since 1983
iTrader: (6)
having broken one primary diffuser last November i have gained additional respect for handling them carefully... i was amazed where the melted plastic found places to roost.
since nothing but air and fuel contacts the diffuser, and neither is going to cause failure, it is most likely that damage is caused on install, re-install or removal. if one of the two supportive legs gets cracked it is all over and the diffuser will be headed into the motor. i don't think it is a function of age rather the force needed to remove/re-install during the porting process.
i note your diffusers (both) appear to be cracked at the base rings also.
i do believe diffusers should be in the motor but they need to be handled w a great deal of respect.
SFYL
howard
since nothing but air and fuel contacts the diffuser, and neither is going to cause failure, it is most likely that damage is caused on install, re-install or removal. if one of the two supportive legs gets cracked it is all over and the diffuser will be headed into the motor. i don't think it is a function of age rather the force needed to remove/re-install during the porting process.
i note your diffusers (both) appear to be cracked at the base rings also.
i do believe diffusers should be in the motor but they need to be handled w a great deal of respect.
SFYL
howard
03-24-11, 09:39 AM
#12
the benefits of running them dont outweigh the chance of breaking them. i aligned the notches right and handled them carefully. i really dont know why they cracked during install. need for a new engine + 400$ turbo rebuild, they staying the out!
03-24-11, 07:12 PM
#14
I would hate to see someone go LS1 when their engine failed for a reason not related to detonation or abuse. Ive never personally seen this happen but have now read/heard about 2-3 engines have this failure. Wonder how many original engines and remans fell victim to this over the years when Mazda was in its peak of building S6 remans? Hopefully you will stay the course and stick it out with the rotary.
03-24-11, 10:30 PM
#16
I have noticed nothing bad from running without them, just cut the legs off so you still use the round part that fills the notch and has the seal, basiclly what the OP found in his motor after the rest broke, just like in Damiens write up:
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/fuel-system-upgrade-how-write-up-kgparts-kit-404091/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/fuel-system-upgrade-how-write-up-kgparts-kit-404091/
03-25-11, 08:14 AM
#17
I would hate to see someone go LS1 when their engine failed for a reason not related to detonation or abuse. Ive never personally seen this happen but have now read/heard about 2-3 engines have this failure. Wonder how many original engines and remans fell victim to this over the years when Mazda was in its peak of building S6 remans? Hopefully you will stay the course and stick it out with the rotary.
03-25-11, 08:16 AM
#18
I have noticed nothing bad from running without them, just cut the legs off so you still use the round part that fills the notch and has the seal, basiclly what the OP found in his motor after the rest broke, just like in Damiens write up:
https://www.rx7club.com/showthread.php?t=404091
https://www.rx7club.com/showthread.php?t=404091
03-25-11, 08:27 AM
#19
Original Gangster/Rotary!
iTrader: (213)
Nice. Next time you troll the rotary section you'll get a vacation for your efforts. Go back to the other engine conversion section where you belong..... see ya at DGRR
On the subject of this thread, I've personally torn down two destroyed motors from the original brittle diffusers breaking and falling into the motor.
We use brand new ones on all builds with oem injectors, have never had an issue. My personal car uses four top feeds, and I'm kinda glad I don't have to deal with them
On the subject of this thread, I've personally torn down two destroyed motors from the original brittle diffusers breaking and falling into the motor.
We use brand new ones on all builds with oem injectors, have never had an issue. My personal car uses four top feeds, and I'm kinda glad I don't have to deal with them
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