2G Spun rod bearing

[raggedgst]

Hey guys, I'm new at this internet thing so bear with me. I have done a fresh rebuild on a 96 GST. Stock everything and 10 over main bearings and 30 over rod bearings. And the balance shaft has been taken off. But I didn't replace it with the Galant piece, just cut the shaft off. But I did turn the bearings around so they would plug up the oil journals and not screw up the oil pressure.

I had a problem when starting it up for the first time, because we didn't connect the throttle linkage correctly and the first few start-ups were at 4000 rpm. Anyway it spun the 3rd rod bearing so I shut it off. All of the other bearings were fine they just looked like they were a little tight. But before I shut it off, I noticed it had low oil pressure. I guess this rambling question is i have three possibilities. Either the high rpm spun the bearing right off the bat, the balance shaft being cut off did it somehow, or the oil pump is going bad and its just low oil pressure.

You guys let me know what you think, so I can plan out my next move. I cleaned up the crank got all the discoloration out and used the mic. and it seems to be fine. So I can either put new bearings on or get a new motor.

I thought that if a rod bearing spun then you would have high oil pressure? But I had low oil pressure.

 

[JNperformance]

Why didnt you get a balance shaft delete kit? They are cheap. This is what happens when you cut corners or balance shafts.

 

[Zex4g63]

Did you put a new oil pump on it during the rebuild?

 

[joe sobo]

im not a professional at machining , but i have been told that its not always a good idea to get a mitsubishi crank cut. the reason is that they are nickel-coated. once you get them cut it takes the nickel away. and the crank surface is not as smooth,,as its now bare metal, which is more porus,and in return eats the bearing up quickly...i was told that its called micro -polishing. and that if the crank needs more work than micro-polishing it, then it may be cheaper in the long run to just replace the crank new........... someone correct me if im wrong

 

[raggedgst]

No I didnt see anything wrong with the oil pump i had. No slack or anything. And i dont see why cutting the crank would hurt anything, poeple do it all the time. The main thing is I am not building a bada## 500 horse motor or anything, just a factory build. An d I made sure to get all the timing marks on the oil pump correct and prime it. I think this is just the case of being to hard on the motor on the first few crank-ups. Plus ACL hard bearings probably wasnt good ont he crank at 4000 rpm for the first few crank-ups.

 

[joe sobo]

i understand what you are saying. but, MOST crankshafts are not nickel coated either.
its just what i was told when i went through two crank in my build

 

[raggedgst]

wow you went through two cranks in your build! thats scary i hope i dont go through that.

 

[Littlebeeper]

cranks are cut all the time but not DSM cranks, well 2g cranks. they state non-servicable. people do and have cut them and have the car run fine but cutting them makes them weaker due to cutting the nitride coating. chevy, dodge, and ford cranks can be cut just fine. hell clearances on those manufacturers wasn't as tight as the Japanese of the same time either