| Also known as | E4010 |
| Diagram | Fig. 4 — CYLINDER BLOCK AND HEAD, 3TA AND T90 · ref 16 |
| Subsystem | engine top |
| Listed in parts books | 1964–1965 |
Inner valve spring
Inner valve spring for Triumph 3TA/T90 and 5TA/T100SS cylinder heads, part number 70-4010 (E4010).
This is the inner valve spring for the top end of the Triumph 3TA, T90, 5TA, and T100SS cylinder heads — the smaller of the two springs that sit on each valve stem, working alongside the outer spring to close the valve after the cam and rocker push it open. The catalog lists it as 70-4010, with E4010 as the earlier letter-prefix number for the same part.
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On these small-twin heads each valve carries a pair of springs, inner and outer, stacked together under the collar and cap. When you're doing a valve job or just checking spring tension on a head that's been sitting, this is the one you want to check for cracks, coil-set, or uneven free length alongside its outer counterpart.
Our catalog record shows this part turning up in the mid-60s cylinder head figures for the 3TA/T90 and 5TA/T100SS engines. If you're working on something outside that range, give us a call and we'll confirm 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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