| Also known as | E4012 |
| Diagram | Fig. 6 — CYLINDER BLOCK AND HEAD, T100S, T100C SINGLE CARBURETTER · ref 14 |
| Subsystem | engine top |
| Listed in parts books | 1964–1967 |
INLET VALVE 500 1959-66 1.430 HEAD DIA
Inlet valve for the 1959-66 Triumph 500 twin, 1.430 in. head diameter.
This is the inlet valve for the Triumph 500 twin, listed for the 1959-66 engines with the 1.430 inch head diameter. It lives up in the cylinder head, one per intake port, opening to let the fuel/air mixture into the cylinder on the intake stroke and sealing shut the rest of the time under spring pressure. The catalog also shows it turning up in the CYLINDER BLOCK AND HEAD figure for the T100S and T100C.
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You'll sometimes see this part called out under its older E4012 form or the V-187 number - all the same physical valve, just different book conventions from over the years. If you're rebuilding a top end on a 500 from this era, valves are one of those parts worth checking closely against your actual head, since Triumph revised head diameters across the run and you want the one that matches what's already in there.
We don't have a lot of extra catalog detail beyond the head diameter and the year span, so if you're not sure which spec your engine wants, give us a call before you order.
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