2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

spining rotor bearings???

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Old Jan 27, 2009 | 06:23 AM
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TX spining rotor bearings???

has anyone on here ever had a problem with spinning bearings in their motor this is the second time this has happened, the first time i lost an oil cooler line on the freeway and didn't notice my oil pressure had dropped to 0 till about a mile later. but this time i spun both rotor bearings but they acualy spun and destroyed the inner part of the rotor so they acualy stayed on my e-shaft when i pulled the rotor out ..... just trying to figure out why this happened any ideas???
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Old Jan 27, 2009 | 06:31 AM
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E shaft pellet fail

if your doing stat gear bearings regularly = wrong counter weights
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Old Jan 27, 2009 | 06:39 AM
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From: satown
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sorry forgot to mention details, stat gear bearing are fine, i have thew atkins thermal pelet replacement, the solid silver one(cant remeber what its called right now) also large streetport and polish,new apex seals and corner seals and all new springs .its an 87 na motor used all the same parts, set endplay with correct spacer, had put all new bearings in, broke in motor for 1800 miles the first time, after the second rebuild drove for almost 3k miles before one day heard knocking in motor knew it was bearings again.
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Old Jan 27, 2009 | 07:07 AM
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well, apart from some random metal still floating around the system

- do you start and warm up on a bad slope?
is your ignition AOK?
ie-- sure the trailing is operational ??
is TDC right????


are you loosing coolant via outer ring into oil cavity?
is your sump evaporative control still working-
-- ie due you have a water in oil issue?

is your oil unusually thinned by very rich mixes??
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Old Jan 27, 2009 | 07:08 AM
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Did you replace your oil pump after spinning the bering the first time? If not, I would suspect that when the berings spun the first time dammage was done to your oil pump and therefore it was a ticking time bomb.
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Old Jan 27, 2009 | 09:13 AM
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Did you replace the oil pump and thoroughly clean out the inside of the cooler after the first failure?

What weight of oil are you running?

Any oil mods?

How was the bearing pressed in? The correct way is to warm the rotor and freeze the bearing, then quickly press it in with a bit of green/grey Loctite to hold it in place.

http://www.aaroncake.net/rx-7/damage.htm
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Old Jan 27, 2009 | 09:36 AM
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Originally Posted by Aaron Cake
Did you replace the oil pump and thoroughly clean out the inside of the cooler after the first failure?

What weight of oil are you running?

Any oil mods?

How was the bearing pressed in? The correct way is to warm the rotor and freeze the bearing, then quickly press it in with a bit of green/grey Loctite to hold it in place.

http://www.aaroncake.net/rx-7/damage.htm
^2nd this, also.......Did you clean the metal out of the e-shaft?
Barry
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Old Jan 27, 2009 | 11:00 PM
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From: satown
No, the first time i spun a bearing was a totally different motor.
i did not clean the oil cooler out, the mods i have on this motor, i believe was the oil pressure regulator crush mod or whatever its called saw it on pineapple racing. but i did not do the mod myself it was already done when car was bought.

i had no water in oil issues. no coolant loss besides a loose hose clamp to the heater core. i run 20w-50 oil. i premix. i have all blockoff plates. motor had originally been rebuilt by atkins had new front cover and many other new parts. motor was running in my friends car for more than a year before we turbo swapped.

knowing that i did not flush out the cooler was most likly my problem but what is the proper was to flush one?

thank for all the reply's.
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Old Jan 28, 2009 | 06:21 AM
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Originally Posted by yudaya

knowing that i did not flush out the cooler was most likly my problem but what is the proper was to flush one?

thank for all the reply's.
Flush both directions with varsol in a wash tank. We had a special pump for aircraft oil coolers that could change directions of flow. After an hour of cleaning we would tap the tank ends lightly to shake any remaining particles loose.

If I remember correctly there was place that cleaned and x-rayed them in Dallas. Southwest Oilcooler I think.

Barry
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Old Jan 28, 2009 | 09:18 AM
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A friend spun a rotor bearing. His timing was horribly off due to a mismatched pulley and hub.
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Old Jan 28, 2009 | 01:17 PM
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From: satown
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hmmm well my timing seemed fine and ran great
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Old Jan 28, 2009 | 02:59 PM
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Personally, I think you should have hit it with a timing light just to make sure it was right before you drove it around for 3k miles...

FYI, the car can be off timing by almost 4 or 5 teeth and still run. I had a friend with one like that, spun a bearing, found out he was off almost 30 degrees on his timing.
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Old Jan 29, 2009 | 01:45 AM
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i hit it with a timing light and it was around 10 degress off i had set the cas to factory settings but a few times it had slipped due to the nut not being tightened all the way
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Old Jan 29, 2009 | 08:14 AM
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Originally Posted by yudaya
i hit it with a timing light and it was around 10 degress off i had set the cas to factory settings but a few times it had slipped due to the nut not being tightened all the way
So it was 10 degrees off but it still rode fine? Ever hear any knocking at high rpm?

If you can weld, I'd suggest modifying the CAS so it doesn't change at all when you put the motor back together.
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Old Jan 29, 2009 | 08:45 AM
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i've spun bearings before and when i did i would get a different cooler. never spun a bearing because of timing before, never seen it either(as there are alot of things i haven't seen). another thing that can cause that is unbalanced rotating assembly. just my 2 cents as i'm no genius here.
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Old Jan 29, 2009 | 09:22 AM
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Originally Posted by killahrx7
i've spun bearings before and when i did i would get a different cooler. never spun a bearing because of timing before, never seen it either(as there are alot of things i haven't seen). another thing that can cause that is unbalanced rotating assembly. just my 2 cents as i'm no genius here.
The motor will knock if the timing is off and if you just ignore it, it will eventually spin a bearing. A unbalanced rotating assembly is usually more famous for taking out the stat gear bearing, which his is fine.

To OP, when you reassemble the engine, make sure you cleaned out all the oil passages, and clean out the oil cooler as well. Possibly even get another one off of one of the members in the classifieds.
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Old Feb 1, 2009 | 02:25 AM
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thasnks for all the replies, i just received another oil cooler and am currently cleaning out my motor irons and oil pump, so the culprit was my stupid oil cooler from the previous motor. thanks for all the help.
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Old Feb 6, 2009 | 03:40 AM
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12aT mazda fuel pump washer in action, flushing oil cooler with diesel

- no sock, just distance, and a little magnet chucked in on the discharge banjo
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