Reply To: Ex Air ministry Alcon Pumps

[sidevalve5]

Hi David,

My Villiers engined Alcon pump is definitely 1½”. It does have a model number on it. I got it from a retiring market gardener, who sold me all the delivery and suction hoses too. It ran poorly, so I did my usual top end, points and carb service, it then ran well. It was noisy though under load and drank fuel. The Honda GX160 is a lot quieter and less thirsty, the Robin EY15 even better on both counts. The pumps have a superior performance than the Alcon too. So am on no particular rush to get the Villiers/Alcon combi running again. Very interested to hear that the pressure gauge had a red line at 20 psi and it rarely achieved that. It explains a lot. A friend of mine got 16 spraylines (they are each 15’ long) with a Villiers/Alcon combi and it never worked very well. He said he then got a Honda pump that ran the spraylines fine. He grew lettuce, watering regularly. He filled the fuel tank full and left it to run dry whilst he went off to do another job.

When I first took the Alcon pump apart, found the seal had all but disintegrated. Vulcan Water Seals were very helpful in identifying a replacement and were keen for it to be added to their database. The Clark pump had been purchased by a chap who had had his house flooded and wanted it in case it happened again. He then moved house and had no further use for it. He started the engine every few months, but did not know he was meant to put a bit of water in it to keep the seal lubricated. When I came to swap the pumps over I could see the damage done, so put a new seal in, again from Vulcan. Just for the fun of it I tested the suction with a vacuum gauge. This is when I found the Alcon pump was not achieving the recommended 20-25 ins Hg negative pressure. The others passed.

Had an idea to increase pressure by pumping from one pump, through another to replicate a multistage pump. But it did not work, the second pump was the Alcon and the Villiers engine struggled with the flow rate from the Clark pump. I did get an increase in pressure, but it was not enough. Quickly realized a multistage pump needs to have a calibrated flow from the first stage to the second and maybe a different impeller design too. My effort was doomed to failure.

Best wishes,

Grahame