connecting rod castle nuts.

I have found that I am missing one of the castle nuts that attaches the rod cap to the rod on a super c "c-123" I have ordered 8 replacements from fasten-all that are grade 8 nuts. Does anyone see any problem with this type of replacement ? I figured on replaceing all 8 so that they are all the same, so as not to slightly throw anything out of balance? All input is appreciated.

My only concern would stem from the term "castle nuts". A lot of folks use the term for slotted nuts. There's a difference. A slotted nut (think of the one that holds your front wheels to the spindles) is a nut of the regular dimensions for its size, with slots cut in the outer surface. A castle nut has an extension on the top of a regular thickness nut, shaped kind of like the cap of an acorn nut, making the whole thing taller, with the slots cut into the "acorn" section.

So . . . depending how well Fastenal was able to match up to your original, it may be a good idea to have eight on hand, in case the design or dimensions of the nuts you get is different from the original. The critical thing, of course, is to have the slots at the right height to be able to get your pins in. As I recall, the original nuts were of the regular slotted design but a good bit thicker than a normal nut of that size, so a castle nut may be just the thing to do it.

I'd at the least use the new nuts on both sides of that one rod cap. If the new ones are castles (meaning they might also be significantly different in weight) I'd consider putting new ones on the other three, as well -- kind of a "can't, hurt might help" thing. You're in there anyway, and why not do what you can to keep things balanced and uniform while you're there?

Your motor doesn't run so fast that a single nut of a different design or a MARGINALLY different weight would destroy anything but, as simple as these motors seem, there was still a lot of engineering that went into their design and specs. So you're thinking in the right direction.

Thanks for your reply, When I get them I will tourque them onto the rod caps "all 8" and I think as long as the cotter pin holes line up I will use them. Scares me a bit as there is a lot of money riding on 10.00 worth of fastners !