Bearing Clearances and oil viscosity

Reply Subscribe

Thread Tools

Search this Thread

Jan 22, 2009 | 08:09 AM

2001 Pewter WS6

Thread Starter

Restricted User

iTrader: (43)

Joined: Nov 2001

Posts: 2,669

Likes: 1

From: Pittsburgh, PA

Bearing Clearances and oil viscosity

Is their some rule of thumb of what oil to use with certain bearing clearances??? I am running .0016 on the mains and .002 on the rods. I am running a forged crank. Would Valvoline VR-1 20w50 be too thick? Would the VR-1 10w30 be a better option if I can find it. This would be for a new L92 416 stroker that will need broken in.

Last edited by 2001 Pewter WS6; Jan 22, 2009 at 06:12 PM.

Jan 22, 2009 | 03:44 PM

XtraCajunSS

FormerVendor

iTrader: (2)

Joined: Dec 2001

Posts: 1,954

Likes: 4

From: Baton Rouge, LA, USA

Those are fairly tight clearances for a performance application. Make sure the engine is thoroughly warmed up before beating on it. I would probably go a little thinner on the oil viscosity. You really want good flow through the bearings to keep oil and bearing temperature in check.

Thanks,
Shane

Jan 22, 2009 | 09:49 PM

wht97ws6ta

TECH Apprentice

Joined: Dec 2008

Posts: 372

Likes: 1

From: Kinston North Carolina

I would run the 10w 30 with those clearances. Like was stated above those are pretty tight clearances for your power level. Be sure to get some miles on it before you lean on it real hard.

Jan 23, 2009 | 04:19 PM

2001 Pewter WS6

Thread Starter

Restricted User

iTrader: (43)

Joined: Nov 2001

Posts: 2,669

Likes: 1

From: Pittsburgh, PA

From what I was reading, the aluminum blocks expand more.

Jan 23, 2009 | 05:06 PM

wht97ws6ta

TECH Apprentice

Joined: Dec 2008

Posts: 372

Likes: 1

From: Kinston North Carolina

Quote:

Originally Posted by 2001 Pewter WS6

From what I was reading, the aluminum blocks expand more.

They do. But you have to take into consideration that the cap is steel. So its not going to affect the housing bore much. Also the cap is what sees most of the load. So with the clearances you are running your only look at eight tenths of a thousandths of oil barrier between the crank and the bearing. Thats way tight from a performance point of view. Most cars now days are coming with rarely less than .002 of clearance, and alot of whats out there now is aluminum. If your going to run it that tight i would run the Joe Gibbs break in oil to start with.