Hello, I was wondering if anyone could help me with an issue I may have. Arround this time last year I bought a jdm b18c gsr from a guy that said the motor had 160,000 km when it wss pulled out of the car. While I had the oil pan off I thought it was a good time to check the main bearing oil clearances with plasti gauge. Keep in mind this is my first time ever dealing with bearing clearances so I don't know too much. But from the numbers I got 2 of the 5 bearings were tighter than factory spec. The numbers I got were 1:0.038mm 2: 0.025mm 3:0.038mm 4:0.025mm 5:0.038mm and the factory spec for a b18c1 is 0.032 - 0.050mm. I was wondering if this was anything to worry about. The 2,3,and 4 main bearings also seemed like they were worn past the first layer. Sorry if what I'm saying doesn't make too much sense but I was just looking for some input as I haven't ever done anything with bearings before. As far as I know it is a stock motor but I also could be wrong. Thank you.
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Did you clean and dry the main bearings before you checked the clearance with plasti-gauge ??? If not, this would cause artificially tight clearance measurements.

 

Yes, the main bearings were clean when I checked the clearance

 

he means did you REMOVE the bearings from the block and main caps and clean and dry the bearings, clean and dry the block and main cap journals, clean and dry the crank, and then install the bearings back in their original locations before setting the crank back in and adding plastigauge?

 

I only took the main caps off and crank out and cleaned the bearings while they were still in the block and main caps and I also cleaned the crank while it was out but I didn't take the bearings out

 

that can cause an issue with checking clearances, because often times there will be oil between the bearing and its seat, which takes up a fairly measurable amount of space

 

Keep in mind pastigauge is not that accurate, should only be used for a sanity check at best, to properly check clearance you need an accurate bore gauge and mics like Mitutoyo or similar quality, not the cheap stuff with poor accuracy. If you want to ensure proper clearance you should really consider pulling the motor out, it will be much easier, but if you want to rely on plastiguage that is your choice. I always say do it right once and forget it, take shortcuts and it can cost you double. Good luck.