| Diagram | Fig. 3 — CYLINDER BLOCK – PISTONS – CRANKSHAFT · ref 31 |
| Subsystem | engine bottom |
| Listed in parts books | 1973 |
Tappet block – right ('010" oversize)
A right-side tappet block machined 0.010 inch oversize for the tappet bore in the crankcase.
This is a right-side tappet block, machined 0.010 inch oversize, listed under Triumph part number 71-3449. It's a service-oversize version of the tappet block that houses the tappets riding on the camshaft lobes, feeding valve motion up through the pushrods to the rocker gear.
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The oversize spec means this block was cut to fit a case bore that's been reamed out slightly, typically to clean up wear or restore a proper fit after the standard-size block was no longer serviceable. It shows up in the cylinder block, pistons, and crankshaft section of the parts book, which is where you'd expect a bottom-end tappet component to live.
The catalog only shows this part appearing once, tied to 1973, so we don't have much more history on it in our records. If you're rebuilding a bottom end and think you need an oversize block, check your actual case bore before ordering since fitting these is about matching the block to the machined bore, not just the year of the bike.
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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