I picked up a B16 bottom end, cheap and complete, supposedly rebuilt, but I wasn't going to assume it was. I just finished taking rod bearing clearances, here's what I got: (those of you who've used plastiguage know it's not an exact reading)

#1 - .025mm
#2 - .035mm
#3 - .030mm
#4 - .030mm

All fall close to the tight (new) end of the factory specs. If anything, #1 may be too tight. They're no where near the service limit. Here's what they look like:

bearing half: slight haze to the face, not highly polished -



crank jouranal: nicely polished. Oil passages very clean -



I have yet to pull the main caps, but crank endplay is withing factory tolerances, so the thust washers are good. It does appear that the motor is recently freshened, so do I replace the bearings while I'm in here, or do I just use them again? I've spoken to Earl about the ACL's. Anyone have any experience with them?


[Modified by 94CivicSi, 6:52 AM 1/12/2003]

 

You are definitely on the tight end.

Plastigage them again. The lowest number in the range of clearances is .032mm.

The bearings should be reusable if the surface isn't marred significantly.

-just the way it's supposed to be.

How many miles are on the motor?

 

while u r there. change the bearings out rod and main. heck u might as well do the rings and thrust washers as well. good luck. HiGhO|{TaNe

 

I think you may have answered your own question. As soon as you questioned it, that should have been a sign to get new ones. Those numbers are IMO too tight.

 

right on guys. Better safe than sorry, thanks!

Anyone using the ACL's? Do they also run tight? Is it possible these ARE ACL's and that's why they're a little tight?

 

ACL's usually hit the middle of the OEM Honda bearing spectrum....yellow's and green's.

No real way to tell how well they'll clearance, other than to buy them and plastigage or mic them.

 

If it was "rebuilt" before then you never know the quality that you are getting. I would suggest buying the correct bearings from Honda. Use the letters and numbers on the block and crank to determine which ones to buy. You don't want bearings that are to tight!!

 

It does look like the bearing in the picture is new. If all of your bearings look new, I would use them. Maybe go one size looser on #1 rod bearing. Plastiguage the mains as well, and replace any bearings that are out of spec. It looks like you got a pretty good motor to start with.

 

Put in new ones and save yourself a headache down the road.