vincer77

I have seen the topic of bolt lubrication discussed here many times. I recently attended the Advanced Engine Technology Conference in Indianapolis and found this comparison of bolt lubes quite interesting. This was presented by Ron Totunno and Greg West of Fel Pro/Federal Mogul.

They measured the stress in cylinder head bolts which are designed to be torqued-to-yield fasteners. That is the fastener is torqued to the yield stress of the fastener creating a more even clamping force for the gasket. They tested 4 different lubricants as well as no lubrication (dry) by torquing the bolts to specified torque values and measuring the stress on the bolts.



They compared
no lubrication
10W30 oil
20w50 oil
CMD#3 lube
ARP Ultra Torque

The results were very eye opening for me. The choice of lubricant is very important to achieving the proper stress in the bolt as shown in this figure



I would guess that even the CMD#3 lube does not bring the bolt to yield. The presenters said that the ARP lube as well as the product by Driven have shown excellent results.

I placed all the presenters graphs in a Google album here:

https://plus.google.com/photos/10060...COz8zczZx9CnEg