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Old 09-13-2014, 11:44 AM   #1
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Default Rebuild, not repeat...spun rod bearing

Oh **** **** **** no no no ahhhggggg ****!!!

Maybe you've been there, maybe you lead a perfect life and haven't. I clearly don't.

I'll try to include all the info I know about what lead to the bearing crush because I see guys getting flamed for not providing info. If you don't want to read all this **** then just look at the shinny pics and speculate away. Or don't.

I am hoping you experienced guys can lead me to the answer so I don't repeat. Thank you in advance.

First the gratuitous pride shot: '02 VVT motor stock internals, BRP kit stock pulleys 8 PSI max, TRDIC, RB header & exhaust, stock ECU, 91 octane.



This all started because the shitty Mazda water pump had a failed bearing at 80k. I tore down the front of the engine and replaced the WP,TB, and seals. While I had it apart I installed a snazzy 5X Racing timing wheel and set it to factory.

Well I fucked up the crank seal install. So because I had left off all the covers I just set the crank @ TDC and clamped the belt to the cam pulleys and pulled the stuff off the crank snout so I wouldn't have to worry about the VC and gasket. I had to do this 3 times After a combo of JB weld and a Redi Sleeve the seal stop gushing. So I put it back together and eyeballed the timing wheel to ~ factory timing. (I had marked the HB for the extremes and center of the wheel's movement)

I went for a fast as hell drive. The car was screaming good and my hard on was enormous. At about 100 miles I got a FLASHING CEL I limped it into a station and checked the oil, let it cool etc. then cruised it to the nearest town with a O'Rielly's and borrowed their scanner ( cool guy there who used to race sports cars at Hallett with his dad) which showed P0012-intake cam too retarded; and P0300-random misfire

I cleared the codes and cruised the car the ~75 miles home with no issues other than the CEL was back within 5 miles.

I pulled it into the garage and checked the timing I honestly don't recall where it was as I received some crappy news and had a few beers that evening.

Next morning I Advanced the wheel about half it's travel and checked timing which showed the left mark @ ~ 5* BTDC 'that's wieird' i thought and proceeded to advance the wheel the remainder of it's +- 6* travel and as I was tightening the HB bolts snapped on off. **** again.

I had family coming later that morning and wanted the car running to show it off. **** you...like you've never done it. So after checking timing again and it being now ~8* BTDC I went for a drive.

I did hear a new racket from the motor and KNEW I should just limp it home but my pride and frustration got the best of me and I revved it to 7k and the #1 rod bearing punished me hard.



As I was pulling the motor apart I found the TB to be loose but had not jumped any teeth.

Question: With 1/2-3/4" play in TB between the wheels can the timing vary without jumping a tooth? And if so would this cause the codes and possible detonation?

All crank journals have some amount of grooving, it is worse at #1 main and progressively better at #5. Did the missing 5.9 gram bolt head throw the crank snout out of balance and cause the high RPM destruction?



OR; Did the crap from the (timing) destroyed rod bearing ooze thru the oil galleys and scour the other journals?

OR; has there been an oiling issue for some time undetected without a proper gauge?

OR; something else? Fresh Mobile1 BTW







PS Vlad (18PSI) is sending me a good crank and rods (of which I plan to use one)

Thanks Vlad!
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Old 09-13-2014, 03:17 PM   #2
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Good start and documentation/pictures.
I honestly don't know what to tell you, its kind of a weird situation. There appears to be scuffing/scoring on your piston skirts and cyl walls, I'd inspect that really closely if I were you. I'd feel really uncomfortable re-using those pistons.
I hope the crank/rods/pump I sent you help out, but I am afraid you might need a full build. Lets hope I'm wrong.
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Old 09-13-2014, 06:16 PM   #3
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High rpms don't cause bearing failure. Bearing failure is caused by lack of oil or contaminated oil.
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Old 09-13-2014, 07:49 PM   #4
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Can you take the oil pump off and apart to see if it's in pieces? You will need an impact drive to take the screws off the plate.
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Old 09-14-2014, 11:27 AM   #5
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There appears to be scuffing/scoring on your piston skirts and cyl walls, I'd inspect that really closely if I were you. I'd feel really uncomfortable re-using those pistons.
I hope the crank/rods/pump I sent you help out, but I am afraid you might need a full build. Lets hope I'm wrong.
I think the pics are deceiving. The marks you see are superficial, maybe oil marks? I cleaned the bore of oil and there is no scuffing and the rings on that piston are clean. The bigger worry is the E cam bearings.

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Can you take the oil pump off and apart to see if it's in pieces? You will need an impact drive to take the screws off the plate.
I knew the pump gear was in tact because I had seen the pics of shattered ones. I opened it up on your advice though and I can't see anything wrong.



THIS is a problem though!!!! E cam bearing with metal shavings presumably from the smashed rod bearing.



I cam bearing...I think the surfaces look ok but I'm not looking forward to pulling the head apart for a solvent bath. I have no idea what I'm doing with this OHC set up.

What say you?

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Old 09-14-2014, 11:56 AM   #6
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The entire motor needs to come apart and the block and head need hot tanked. You need to pull the wrist pins and make sure they're clean as well. You also need to let the machine shop inspect the crank and at minimum the rod where the damaged bearing was for roundness.
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Old 09-14-2014, 01:42 PM   #7
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Yeah, it won't be a quick re and re. Will have to clean everything. Head oil gallery bolts need to come out and everything cleaned.
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Old 09-14-2014, 11:05 PM   #8
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The entire motor needs to come apart and the block and head need hot tanked.
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Yeah, it won't be a quick re and re. Will have to clean everything. Head oil gallery bolts need to come out and everything cleaned.
Yup

Any other thoughts about the cause?

I bet the cylinders need honed and new rings too huh? This going to get spendy.
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Old 09-15-2014, 12:43 AM   #9
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I would do new rings and hone no matter what, because they are only like 60-100.
And like the guys said - this thing needs some serious cleaning if its got shavings everywhere.
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Old 09-15-2014, 02:10 AM   #10
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Yup

Any other thoughts about the cause?

I bet the cylinders need honed and new rings too huh? This going to get spendy.
What kind of oil did you run in the car? Heavy weight? Did you warm up the car before revving it to 7k? Cold oil can definitely cause bearing failure. But other than that some sort of major oil starvation unless there was something else that failed and the bearing was the results of it. When was the last time you had check the oil?

And yes definitely do new rings and hone at a minimum.
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Old 09-15-2014, 09:25 PM   #11
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Mobil1 5w30 drove it ~5miles to the "test track" definitely warm.

Any do's n dont's for ring selection?
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Old 09-16-2014, 10:47 AM   #12
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Quote:
Originally Posted by bcrx7 View Post
Head oil gallery bolts need to come out and everything cleaned.
***VERY IMPORTANT

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Mobil1 5w30
Not a great choice, imo.
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Old 09-16-2014, 01:07 PM   #13
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Mobil1 5w30 drove it ~5miles to the "test track" definitely warm.

So... Oil takes a lot longer to get warm than water - 5 min may not be long enough to warm the oil depending on the local environment (air temp & car speed).

Other factors that may contribute are: using an oil cooler adapter without a thermostat, restrictions due to too small diameter oil cooler lines, too small of an oil cooler, thick oil... (thick oil is likely not an issue here with 5W30)

I suspect the failure scenario goes something like:
- Oil in the pan is cool and thick (ish)
- Oil pump attempts to push oil through - oil cooler adapter, possibly restrictive oil cooler line, cooler, another oil cooler line, oil cooler adapter, then on to the oil filter, and finally to the engine.
- If the resistance at the oil pump is too high going through all the above plumbing, the pressure relief valve located at the pump will open (partly) and dump oil back into the pan. In this scenario, the engine oil volume may be reduced (but may still be high enough pressure at the oil sensor to not be seen as an issue on the NB gauge).

Net effect is borderline oil pressure to keep all the bearings happy. It may be fine on idle or low load but not high RPM or high load or both.

The issue is at high RPM, oil is thrown off the bearings (especially crank) faster than fresh oil arrives. This can lead to oil starvation even though there is lots of oil in the pan, the pump is working fine, etc.

My guess on the cause of failure is too eager a right foot / too much RPM...
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Old 09-16-2014, 01:48 PM   #14
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Mobil1 5w30 drove it ~5miles to the "test track" definitely warm.

Any do's n dont's for ring selection?
Yes, 5miles is not definitely warm! You need to drive the car at least 15-20mins before doing hard pulls to redline and of course if that 5 miles is downhill, then that is worse. In addition 5w30 is not the best option. Where are you located at? Perhaps for winter, but I would do minimum 10w30 or 10w40 on a boosted engine in summer.

Oh and I see oil cooler block in one of the pictures. Does that oil cooler have some sort of a thermostat? If it doesn't even 10-15 minutes might not be enough to warm up the oil. That is most likely your problem. Repeated pulls on the engine over time with cold oil. On a race track it might take 3-4 laps on a cold engine to get the oil temperature up to what the water temperature is. That's 8-10miles of harder driving. Not stop and go around town.

Reading your profile, it says S/C and Nitrous. Was the nitrous used on this run? What are you running as far as management???
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Old 09-16-2014, 09:32 PM   #15
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No NO2. I've changed that twice I think. Apparently not.


So going forward I should install a tstat in the oil cooler line (any suggestions?) add an oil temp to the oil pan and never hit full boost/redline until 200* and change viscosity to 10w40?
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Old 09-16-2014, 09:35 PM   #16
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Any thoughts as to the VVT and misfire codes?
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Old 09-16-2014, 10:47 PM   #17
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No thermal control on the oil cooler? Ouch.

You probably trashed everything in the VVT mechanism when you filled it full of bearing shards. If you have metal in the cam bearings I would hazard a guess that you probably have metal in the VVT parts as well. Is the little plastic oil filter screen still in place inside the oil control valve?

Your oil cooler is probably also full of metal. Toss it and buy a thermostatically controlled oil cooler kit from someone like Trackspeed. I'm not sure I would be willing to trust the old cooler to actually get clean at this point. The Mocal thermostat used in the TSE kit is pretty much universally accepted by most folks.
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Old 09-16-2014, 11:23 PM   #18
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yep, you pretty much have to go through the whole engine piece by piece.

and don't even get me started on clogged vvt valves. it still hurts
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Old 09-16-2014, 11:56 PM   #19
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The oil you are looking for is Rotella T6 synthetic. It is in a blue gallon jug at Walmart. It only comes in one flavor.
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Old 09-17-2014, 12:42 AM   #20
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Are you guys serious with the oil temp thing? A trip around the block will heat the oil enough to make it uncomfortable to pull the drain plug and have it on your hand. After 5 min of driving the oil would be very uncomfortable on your hand like putting it under the kitchen faucet turned to hot.

I almost never run my car for 5 minutes before flogging it at an autocross. Never had an oiling issue.
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