so i bought a b18b1 motor a few months back and not thinking i took it apart fully so its a bare block without thinking did lable bearings not lable which rods came out of were so my question is how do you measure rod bearings and does it matter which cylinder the rod goes back into

 

measure the rod



then with bearing



then u must measure the crank journal with a micrometer.
Inside Bearing diameter - crank journal = clearence

 

Just to add, you must torque the rod bolts down to whatever torque value you are using when measuring with an inside micrometer for the width.

 

Inside micrometer isn't preferred but with the right feel you can get close. The preferred method would be a dial bore gauge. There are actually a few methods on how to get proper clearance and some of them don't require having bearings on hand.

 

thanks for the info but i don't have the bearings

 

In a perfect world, yes. However, I wouldn't recommend using a dial bore gauge on the actual bearings themselves if its the cheaper sets . . . seen way too many people leave an indention/line in a bearing. Perfectly fine for the I.D. of the rod/main without the bearing or cylinder bore diameter.

I use an expanding 3-point inside micrometer for checking the bearing I.D. when torqued in a rod or main cap. The points have a small radius to get a single line of tangency and are next to impossible to mar the bearing surface.

 

is there a really good way and simple way to find out what size/color bearings i need since i dont have the origanal bearings on hand by the way im building/putting the motor back to gether to origanal specs

 

Interesting, but I have never marred bearings from using a dial bore gauge. Maybe you have much preload on the tool? Either way the OP was looking for a different direction obviously - no tools at all haha!

OP - You need to measure everything to make sure it is in spec before you proceed. If you don't care then just get the same color bearings you have on hand. Simple as that. There are marks stamped in that tell you the color code for the bearing on each journal. Just match the code to the bearing chart.

 

Its primarily been from those chinese sets . . . the $90 ones you can buy off ebay or whatever. Now that I think about it, it may the quality of person using a $90 bore gauge set over the gauges themselves.

I've used a mitutoyo without incident but it was $500 . . . when it measured everything within .0001 of this brown & sharpe 3-point, I just started using the 3 point because its faster to setup.

 

a dial bore gauge or mic set are the best two options/methods, though they are not cheap tools to buy.

on a small budget some green "Plastigage" used per the instructions is a good "pass-fail" clearance check for a mostly stock, daily driven rebuild. high-performance, high-stress track-driven builds are worth the expense of proper measuring apparatus.

 

My $60 dial bore gauge has yet to let me down...

More important is the tool you are using to "zero" it...