what's the clearance between the rod bearing and the crankshaft

[Stainbox12]

I've been looking through the forums, but i didn't find an accurate answer. I would like to know, what's the clearance between the rod bearing and the crankshaft. I have chilton's but i found that it might be there but its in complex words, and i don't seems to find it Easly. Thanks in advance for any info.

 

[XtremeRS2gnt]

Rod bearing oil clearance is .0008" to .002". Main bearings are the same. I believe .003" is the max service limit. I built my 4g63 with .0015"-.002" for mains and rods.

 

[Maglin]

Main's are .0008-.0016" and torque is 47-51 ft/lbs
Rods are .0008-.0020" and torque is 37-38 ft/lbs

That is out of the book.

 

[drivemusicnow]

but you never ever ever want to build a preformance engine on the tight end of those specs. Even a stock engine built tight can have problems with thicker oils.

 

[Maglin]

And that is why you don't run thicker oils. If you build an engine on the lower end of the spec then you would definitely want to run thinner oil. I like 0W-20 synthetic. Going really loose and running a thicker oil is like bandaiding IMO. It will work. A lot of high output high strung motors are built pretty tight these days. And they all run a very light weight oil. It helps with cold starts and fuel economy (because of less friction). I wouldn't go .0008 but .0010 on my clearances if I had the bearing choices to actually attain that on each and every bearing.

I go on the average of what I see across the board and swap bearings around until I can get as constant as possible for my bearing clearances and run an oil weight that is good for those clearances.