| Diagram | Fig. 1 — Engine: Crankshaft, Connecting Rods, Pistons, Camshaft, Timing Gear · ref 4 |
| Subsystem | engine bottom |
| Listed in parts books | 1971–1972 |
Norton Big End Shell Upper
Upper half of a big end bearing shell for the crankshaft/connecting rod assembly, listed for 1971-1972.
NM.25384 is listed as a big end shell, upper half, in the crankshaft and connecting rod section of the engine parts book. It's one of the two-piece bearing shells that sit inside the connecting rod big end and ride against the crankpin, carrying the load between the crank and the rod as the engine runs.
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Our catalog record for this one is thin - it shows up in a single listing tied to 1971-1972, and we don't have partner descriptions or supersession data to fill in specs like size or material. Big end shells are normally sold and fitted as a matched set with the lower half and selected to the crankpin's actual dimension, so don't assume this one drops in without checking against what's on the bench.
If you're rebuilding a bottom end and this number is what's printed in your parts book, give us a call and we'll confirm exactly what it takes before you order.
We've never carried this one. Tell us what you're after and we'll go looking — you'll get a price and photos before you commit to anything.
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