346 Connecting Rod lock washers....again

[DaveZ]

So I have searched the forums and have seen some answers about the special washers. I read that Egge had them, but they were not quite right? Has anyone since had any luck and what did you end up using? I would have imagined there would be barrels of them laying around in some warehouse from WWII surplus packed in grease and wax:-)

[Tom Beaver]

 Dave,

Here is a reply I made to the same question a couple of years ago.  I purchased a set of those lock washers from Egge but the ones they sell are not an exact duplicate of the original.  They are thicker and hence stiffer.  I talked to the technical people at ARP to see if they made any lock washers that size and their reply was that they did not make any lock washers at all for anything and did not recommend them for this application.  It appears that engine manufactures stopped using lock washers on rod bolts and went to flat washers a long time ago, since proper torque of the bolts causes them to stretch elastically which provides the same function as the lock washers.  ARP however, does make the correct size flat washers which are hardened and chamfered on one inside edge to clear the transition radius at the bolt head.  The ARP part number is 200-8501.  I purchased a set for the rod bolts in my engine.

Tom Beaver

[Bob Hoffmann CLC#96]

Dave,
I'm not sure how compressed your washers are. I have a set that look very uncompressed. Removed from a motor many years ago. Contact me at bobscads@comcast.net
Thanks, Bob

[DaveZ]

Thanks guys. I know the ones I have were only used once. I'll carefully check them out and see what happens after that.
Dave

[Ron Parker]

Tom, How did those arp washers work out? Did you use Locktite? Red or blue? I have had several break and I don't trust the used ones. Has anyone used the Egge washers? I am concerned about the thickness since the thread contact with the stock washers is not 100%.Thanks Ron Parker

[Tom Beaver]

I have had no issues with ARP's flat washers as a replacement for the original split washers.  The original washers were designed to be used only once and the factory manual states that they should be replaced.  I had first tried re-using the split washers, this was before I talked with ARP.    I had two sets of old washers so I sorted through them  and picked out those that looked ok.  I put them on the rods and torqued them to spec.  I subsequently changed my mind before I buttoned up the engine and removed them and replaced them with ARP's flat washers.  Of those old washers that I removed from the engine, at least five or six of them had broken just from the process of torquing them down.  Based this experience I certainly would not recommend reusing the old split washers.

Tom Beaver

[Bob Schuman]

I discussed this with a friend who builds very high performance big block Chevy engines using custom made aluminum blocks, for drag boats, drag cars, and pretty wild street machines. He agrees with the use of hardened flat washers and for a little more assurance, Loctite Red on the clean and dry threads. He has seen lock washers fail, sometimes spreading out from under the bolt heads, and said he would never use lockwashers on rod bolts.
Stock Cadillac flatheads do not see anywhere near the usage such high performance engines see, but I respect his views and would not feel confident using the Cadillac lockwashers unless you could find good NOS Cadillac parts.

[Ron Parker]

Thanks Tom,I used the ARP washers with blue locktite are I feel confident after torquing the bolts that it will be fine. Ron Parker