main and rod bolts wet or dry

[87turbot-type]

Just wondering if you trq the main and rod bolts wet or dry.

Thanks

 

[Chuck Leeper]

Depends..

Just wondering if you trq the main and rod bolts wet or dry.

Thanks

on the bolt mfgr's recommendation.
VERY likely NOT dry.
There varying torque specs, depending on many factors. Some are:
Fastener design.
Thread design.
Type of lube used.
There are many more, but this will give you an idea.

Cleanliness is of a prime concern. BE SURE the fasteners are CLEAN, as are the holes they are threaded into. Use CLEANING taps, NOT regular thread taps. These are available from Summit, etc, and are not expensive. Use of regular taps will remove the dirt, but will also remove some of the thread material.

Here's a start for info:
ARP | Tech - Installation

NOTE THIS Section:
2. The lubricant used is the main factor in determining friction, and therefore, the torque for a particular installation. Motor oil is a commonly used lubricant because of it’s ready availability. If less friction is desired in order to install the fasteners with less torque, special low friction lubricants are available. With special lubes, the required torque can be reduced as much as 20 to 30 percent. It is important to keep in mind that the reverse is also true. If the torque value has been specified for a particular fastener on the basis of low friction lube, installing the fastener with motor oil will result in insufficient preload; the torque has to be increased to compensate for the extra friction caused by the motor oil.

 

[87turbot-type]

Thanks for that info.

What I am trying to do is install new bearing stock bolts with the gm trq specs. I didn't read any where in the manual that lube should be used?

Thanks

 

[87turbot-type]

never mind found it in the manual.