I am restoring a 57 country sedan wagon with a D code 312. Opened up the motor to have a look at the bearings and found it to be pretty fresh. I did find something that I had never seen before. The rod nuts had pal nuts on them. A couple of them were bent like they had hit something but I couldn't see any witness marks on the pan or block. The motor had a rebuiders tag on one of the freeze plugs I imagine they put the pal nuts on during the rebuid.
Never encountered them before and wondered if I should keep them or remove them ?

Pete

If memory serves me right they were used on earlier engines but not later ones. When doubt, replace them with ARP bolts. They do not use pal nuts. I would recommend replacing them if you have it apart that far. A broken rod bolt is not a pretty thing. I have a very mangled rod hanging above my work bench to prove it. The hole it put through the block and oil pan was also ugly. Happened when my X wife was driving the car back in the day. That is another disaster story for another day.

Many rebuild shops dismantle using air tools and often the pal nuts take a beating. Some shops reinstalled them, while others simply discarded them. If everything looks to be in good order, you can retorque the caps and run without the pal nuts. If you're going to use the 312 for any performance type driving, you should look at installing new ARP fasteners.

Larry D

Winnipeg, MB Canada Eh!


'57 Fairlane 500 Club Victoria

'58 Custom 300 Tudor

'56 Crown Victoria

'61 Starliner Z Code

'51 Ford Victoria

Having found Pal nuts laying loose in the pan early on, I simply don’t use them on the stock type engine rebuilds. Putting the proper torque on the rod bolt insures the correct stretch which in turn keeps the rod nut in place.

Lorena, Texas (South of Waco)

I agree with Larry D's comments.
Remember that if you choose to replace the rod bolts, you will need to "re-size" the big ends of the rods to keep the caps in perfect alignment. The machine shop will also install and hone the wrist pin bushings and align the rods and pistons. You might as well rebuild the complete engine!
If the bearings look good, I'd put it back together using some assembly fluid or lubriplate and leave the pal nuts off.
Just my opinion.

"FREE SAMPLE"

Thank you gentleman for your input. This is a stock engine that will be used in a non high performance application . Since my inspection has revealed a low mileage "healthy" motor I will be changing the timing set resealing the motor and putting it back in service.
As for the pal nuts I will not be using them as was suggested but rather lube the threads and torque to factory spec.

Thank you all again.

Pete