Rod Bearing Assembly Lube

Okay, I found conflicting information online, so came to the only place where the truth resides.

When assembling a new rod, should you, or should you not apply lube to the back of the rod bearings? Of course the face will get lubed. Should the back be dry or not?

 

Why would you put it on the back?

 

I personally assumed you wanted it dry. But I read that some people either use moly lube or just oil on the back to avoid metal on metal.

 

The back Should be dry. Only lube the actual bearing surface.

 

Thats a place you want metal on metal. The rod should spin on the polished journal only

 

First I've ever heard of it. Would be interested in what the logic is to it.

 

I watch all the Power Nation vids on Utoobz and I've never once seen them apply assembly lube to the backside of the bearing surfaces.

 

I guess when you spin a big end it will only fuck it up pretty good instead of really good. At least you will have something to ponder.

 

Never on the backside. Clean and dry.
However, I have heard that burnishing the bearing surface with some paper will decrease the surface imperfections.
I don't know if this is some crazy old school technique or not.
I don't do it, but would love to hear what anyone else thinks about it.

 

Cool, clean install it is.

But out o curiosity I dont think grease would cause it to spin, doesn oil get behind it anyway?

 

Oil doesn't get behind it. It gets on the face from the drilled crank journal.
Grease behind it will change your torque value.

 

Here's a crazy old school technique to try, how about reading the service manual?

And rods are designed to clamp/hold so to speak, the bearing halves tightly so crank can spin inside them.
Ever heard of a spun rod bearing?

 

Isn't there a notch, that prevents the bearing from spinning.

 

That notch won’t even stand up to the torque on a Ninjette!
It’s for locating the shells. The clamping force holds the bearing in place with proper lube. Skimp or loose the lube and a shell will weld to the crank journal and spin

 

You're right, bearing crush.

 

After some research and in response.

Mahle/Clevite says if you want to clean up the surface of the bearing to use newspaper to polish it.

So while it strictly is not spelled out in a typical FSM, it is a technique used by some engine builders.

 

Oddly enough a Youtube vid came up on my feed addressing this very issue. I'll put it in the Youtube thread for your viewing.

 

Jay from Real street performance with the fastest street Supra in the world who assemble some of the fastest 2JZ engines in the world puts oil on the back of the bearing.

strange but that dudes amazing at his job.

 

Is this in relation to the Mopar 318, or the Mopar 340? Similar engines but kinda different.