Rod Brg Cap, Main Brg cap Torque 1925/26 G70 219ci

[cricketkj26]

Can someone please advise what the correct torque is suppose to be for the crankshaft main bearing caps and connecting rod caps. Thanks, Cricket.

[Guest]

Torque wrenches were no available until the mid thirties.  Most mechanics just knew by trial and error. All of my early books suggest tight enough but not tight enough to break.  Here are two tables compiled at a later date that give suggested torques.

[cricketkj26]

Thankyou for the information. It gives me something to go by at least . Cricket.

[Gunsmoke]

Key for rod and bearing caps is that they be tight and not loosen, rather than relying only on "torque". For example, many rod caps in the period used castle nuts which were tightened firm (say 50 ft lbs), and then backed off to nearest hole for a cotter pin. Resulting "torque might be only 40-45 ft/lbs. Similar for bearing caps, perhaps a tighter torque (120 ft lbs seems high), but still backed off for a pin, some bearing caps used a "locking" plate to keep the nuts from loosening. Lock washers were used in some cases, making torquing problematic. My understanding is that using lock washers relies on the washer to prevent loosening, and not on torque. So, suggest you do some further checking specific to your engine with a seasoned mechanic. 

[cricketkj26]

Yes the mains and rod caps have castle nuts and cotter pins on this engine. Thanks for the info. I will see if I can get some more specific quide lines for these early

Chrysler engines.  Doe anyone out there that run this engine have any additional info on the proper tightening of the main and rod caps. Perhaps I should post in the 

technical forum as well.  Thank you both. Cricket.  

[Guest]

A friend of mine who was a Packard mechanic said they were taught if the cotter pins didn't line up at the correct torque they removed the nut and filed it down until it all lined up perfectly.  This is the way I did my rod bolts when I overhauled my engine.  It really doesn't take long.  Some lined up first time and some only needed sever strokes of the file.

[Spinneyhill]

Here is a page first put up by @keiser31 I think.

[cricketkj26]

Thank you for the info Spinney !   Cricket. 

[Spinneyhill]

32 minutes ago, cricketkj26 said:

Thank you for the info Spinney !   Cricket. 

Pleasure. Note that there are experts on these fora who have said those bolts should be replaced when you overhaul an engine. The old ones will have stretched and may not take the tightening torque they once did. Anyway, you are always guessing what the strength of the old bolts was and when you use new ones, you know and can tighten with more confidence. Be Careful, however, on the mains because you are still tightening into the old cast iron block. Hopefully no-one has cut the threads in there a second time under the guise of cleaning them.

Edited November 25, 2018 by Spinneyhill (see edit history)

[cricketkj26]

I was wondering about that - just going ahead and replacing the bolts.  Youre right about the threads for sure.  Learned that the hard way myself on a number of nuts and bolts that I used std dies and taps to  just " chase the threads ".  Then  I found out out on these AACA forums  there really are " Thread chasing Dies and Taps" which I now have a set of them. They are not found at a hardware store or a Home Depot either. One has to order them in.   Cricket.