Spun bearing

[Vman911]

I just recently rebuilt my motor less than 1k ago. I Put a Evo3GT turbo on car with a manuel boost controler. Well It wasn't working too well even turned all way out the car was boosting over 20psi. I did it like 5-6 times of overboosting. Could that have caused my rod bearing to spin?? thanks for help Vinman

 

[91gsx_turbo]

Your turbo could have put alot of pressure on one of the cylinders and caused the berring to get hot and grab on to the crank.

 

[herostar]

It could have, but the most common reasons for spinning a rod bearing are over-revving or worn out bearings. They wear thin and then slip out of place.

 

[Vman911]

Thanks for info. The rod bearings were brand new less than 1k on them. I did a complete stock rebuild from bottom up. Vinman

 

[95blackGsTurbo]

Should have known when it was overboosting something was wrong. Sometime's it is as simple as you are using the wrong size vacuum line for your MBC and it isn't sealing properly. But yes overboosting can cause excess heat and pressure on a bearing and cause it to sieze.

 

[91gsx_turbo]

i let my friend drive my 91 gsx 2 weeks after i got the head on my car and he redlined 3rd gear and was going into 4th and hit 2nd and spun the #1 rod berring since then i havent let anyone drive my car

 

[Steve_P]

if it's not knocking a rod bearing hasn't spun. Is it knocking?

 

[Vman911]

Yes it was knocking. Took out motor replaced all bearings. replaced #3 piston. Put back together....check timing 3 times...Try to start car and timing got 180 out.... Took off head, checked valves, put back together and fired it up yesterday. ran good.

 

[power=dsm]

WTF Is it just me or something else is wrong here. He rebuilt his motor 1k miles ago. And the car spun a bearing boosting 20 psi, doesn't make sense.
I would rather thing something went wrong in the build, rather than you running 20 psi caused you to spun a bearing.

-wHAT BEARINGS did you use in the rebuild?
-Did you check the spec on the crank, and rods to see if they were good.
-Did you check the end play of the crank?
-Did you check the oil clearances?
Maybe the bearing was bad; but their is no way running 20psi is to blame. You running the extra boost put more stress on the bearings which brought about fault in them.

 

[MyBeatGSX]

WTF Is it just me or something else is wrong here. He rebuilt his motor 1k miles ago. And the car spun a bearing boosting 20 psi, doesn't make sense.
I would rather thing something went wrong in the build, rather than you running 20 psi caused you to spun a bearing.

-wHAT BEARINGS did you use in the rebuild?
-Did you check the spec on the crank, and rods to see if they were good.
-Did you check the end play of the crank?
-Did you check the oil clearances?
Maybe the bearing was bad; but their is no way running 20psi is to blame. You running the extra boost put more stress on the bearings which brought about fault in them.

I'd have to agree with that. Many people here run well over 20psi on bigger turbos and high mileage engines without a problem.

 

[91gsx_turbo]

i ran 20 psi on a motor that had 160,000 on it and nothing happend until i got fuel cut, but did he put the berring in right and use plastigauge to check the berring clearence.

 

[Vman911]

Its not my rebuild...
I used clevite tri metal bearings. Yes I checked all clearences. etc.
When I said 20 psi, Well I was using some piece of crap MBC and when I would put the pedal to floor and take off the boost would go way over 20 psi and the car would slam kinda like fuel cut. Could have been detonation. Did another rebuild and put a Profec B on this time and running 11 psi. So far so good. got 300 miles on it. When I hit 500 I'll turn up boost to 18. wish me luck..
Thanks for all your input Vinman