Grey Flash 2751

The history and restoration of a Vincent HRD Grey Flash

The T32AS stop valve is a device fitted between the UFM and the oil feed pipe to the engine. When the union on the valve is disconnected and withdrawn, a valve – akin to a plunger – is forced against a seat, sealing the union and preventing oil from leaking out. This means the UFM can be removed from the engine without the need to drain the oil out first – clever stuff! This contrivance was also fitted to the Grey Flash.

This is what we were presented with once it was detached from the UFM.

An original part, the assembly was lacking the internal valve as this would have been an impedance to the high oil flow critical for a highly developed racer.

When Bert removed the UFM, he was surprised to hear that something was rattling around inside the oil tank. Investigation revealed a drilled metal pipe. This provoked much head scratching – how the hell did it get in there in the first place? Such were the dimensions of the pipe that there was no way it could have been introduced through the filler neck and thus was impossible to retrieve… We eventually deduced that this sleeve was originally situated over the gauze strainer of the stop valve (see pics) – it must’ve been a push fit onto a boss on the female part that the stop valve screws into. At some point it had become detached – it would have been like that for decades and raced with it rolling around loose in the UFM… We will have to leave it as-is as there’s no way of getting it out without cutting a hole in the oil tank! The oil return metering valve assembly, in the tank filler neck, gets in the way…

Once cleaned.

The internal valve plunger will be procured and reinstated. This small dull chromium plated part is original to the bike – great! 🙂

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