Singer Owner March 2002

Roadster Repairs Flexible Petrol Pipes

Ashley Crossland

Yet another age-related disaster on the 4AC Roadster; this time petrol leaking from the flexible petrol pipe that goes onto the carburetors!

In the January 2002 issue I described how the rubber, lower front wishbone mountings had perished after 20 years of service. The good news is that the rubber bushes, part no.RACA 5242 are still available from Rover dealers. Current price £1.40 each. However, it seems that 20 years is a good life for rubber components and therefore not surprisingly the rubber cored petrol pipe also decided its time was up.

Now dealing with parts on my 4AC Roadster, (remember it's number I and therefore very much the prototype of prototypes) is usually a headache. So what might Singers have used for my petrol pipe? Well, for once I was pleasantly surprised, because they had the standard 4A Roadster petrol pipe. It's used in a slightly different position, but nevertheless the same flexible.

On the A, 4A and 4AB, 9hp engines the petrol flexible jumps the gap between the right hand chassis rail and the mechanical petrol pump on the side of the engine block. This hose is 7 3/8" long with one end being slightly curious, a 7/16" x 24TPInut and olive, whilst the other end a 1/4" BSP nut, both ends being "female". It was one of these pipes that Singers had used on my 4AC to go from the bulk-head tool deck to the first of the twin carbs on the 1500cc engine. The 4AC petrol supply is not standard, with a fixed copper pipe coming to an electric petrol pump on the rhs of the tool deck to finish in line with the carburetors. It's from here that the flexible fits.

This particular flexible was in common use at Singers. They used it on the 10hp saloon in the same way it was used on the 9hp Roadsters. Indeed they had similar pipe coming off the engine oil supply to feed to the oil pressure gauge. These 9 and 10hp engines used a pipe 9" long with a 1/8" BSP female on each end. One wonders if they could not have rationalised a bit and used the same pipe for both duties. During the early 1950's, Singers were in financial trouble, and any cost savings would surely have helped. So it's against this background that we suspect Singers could not place bulk orders with supplies for their specialist requirements, and had to do with "off-the-shelf" alternatives. Either that, or they were having to swop suppliers when their credit ran out. Whatever reason, it's hard work making sense of Singers spare parts lists for these flexible pipes.

Anyway, let me try and make some sense about things. Our 9" long oil pipe conveniently gets used for the oil pipe on the 4AD Roadster engine, (and incidentally also for the oil pipe of the SM1500 saloon). And the 7 3/8" long petrol pipe continues in service when the Hunter engine adopts the mechanical fuel pump, and this pipe with the funny end, jumps the gap from the chassis to the pump.

However the "standard" 4AD Roadster (as compared to my 4AC) had its petrol pump on the front of the bulkhead ("below" the battery) and used a fairly long 19" flexible to go from the pump to the carburetor(s). This was fitted with the same ends as our other petrol pipe, i.e. the funny 7/16" x 24TPI thread and a 1/4" BSP And incidentally this same 19" pipe featured on the SM1500 saloon fuel system.

So why the funny thread? Well it's not that funny really as it's the standard thread on an Enots' fitting, the company that produced a lot of pipe fittings, and especially for petrol systems.

That's about it for this time. Hopefully there's some information here to help owners check up on the originality of some flexible pipes. But the important safety message is that rubber in fuel pipes does perish, and a fuel leak is dangerous!