| Also known as | AA23, E2254 |
| Diagram | Fig. 1 — CRANKSHAFT AND CONNECTING RODS · ref 39 |
| Subsystem | engine bottom |
| Listed in parts books | 1960–1962 |
ROTARY BREATHER VALVE TRI 1944-62 (For later use 70-5316)
The rotary breather valve fitted to Triumph engines from 1944 to 1962, later superseded by 70-5316.
This is the rotary breather valve as fitted to Triumph engines from 1944 through 1962, also known by its earlier part number AA23. The breather valve is what lets the crankcase vent excess pressure as the engine runs, and on these older engines that job was done by a rotating cam-type valve rather than the later reed-valve arrangements.
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Our records show this part carried on through a long run of pre-unit production before Triumph moved to a revised breather design. If your parts book or an older stamped number in the timing chest area is calling for this valve, 70-2254 is the number you want, with AA23 being the earlier form of the same part.
We don't have much more written down on the specifics of fit or hardware here beyond the years and the later replacement number, so if you're working on a rebuild give us a call and we'll help you confirm it's the right one for your particular engine before you order.
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