The rods on my 1962 650SS which I am preparing to rebuild are the Commando-type with additional oil holes at the big end (NM23258).
Close examination shows some minor damage to one of the rods in two places.
Minor may not be the correct adjective in connection with rods (no pun intended).
As these rods are of unknown provenance, I am minded to replace them as I will have a new crank (incl bearings etc), new +0.010 Hepolite pistons (incl rings, pins circlips etc) in newly honed barrels to suit and a completely refurbished cylinder head (incl valves, guides, seats re-cut, pushrods, rocker balls etc).
If I am to replace, what is the preferred option - I am minded to go with steel Hepolites but other options include new NM23258, Thunder Engineering or R&R.
I want to maintain the high pressure oiling as I will be fitting a new higher output pump.
Any recommendations/ cautions?
Thanks
Alastair
Remember you'll need to…
Remember you'll need to account for the larger pin diameter if using a rod without a bush. The small end diameters were the same diameter whether you had a bush or plain small end, but the pins used in the plain small end are smaller in diameter.
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if those rods are otherwise straight/ parallel etc, they could be polished out, IMHO.
Otherwise, I would go for the NM23258 option.