Ex Air ministry Alcon Pumps

[davidbliss]

These were bought sometime in the 1950s, ex air ministry. One was seized and was only used for spares. The other one also came crated with a multitude of spare parts, this was used for years and we never realised the differences between to the two pumps.

The one Jap engine has no governors and internally the valves only have the normal single guide, the cam shaft has large gear teeth. It also had screened ignition with what looked like and aircraft plug in. This was difficult to get but this was replaced with a normal plug lead and plug.
The other engine had governors and the valves were supported in two guides, which is unusual. The normal guide at the top and another below the spring. The cam shaft had fine gear teeth.

The one without governors revd upto 4000 which way above the 2400 that the manufacturers said. It also fast primed which is probably why.

With me being inquisitive as a young boy. I pulled the spare pump apart, but it then got pushed into an empty bath for 40 some years in bit. In the end for something to do I got it out, reassembled and it actually goes.

Does anyone know what the differences in years are and also why they had these differences.

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[andyfrost]

I’ve worked on quite a number of 2As , and have seen both types of camshaft , but have NEVER seen one without govenors , out of interest is the block machined to take the govenor shaft. I can’t envisage a 2A lasting very long at 4000RPM…… something doesn’t seem to add up here.

Andy.

[davidbliss]

The one on the right that did have governors just has the one small brass plug carburettor side, I found you had to hold the governors open to be able to prime in a reasonable time and when it did the governors just opened the carb to full throttle so they were of really no use so did away with them. However the engine started to knock in only two hours of use, the white metal in the big end shell had just been squeezed out and it looked as it was very soft. The other engine been running ok for around thirty years and never had a issue, took a good look at the carbs they were slightly different the un-governed the butterfly only partially opens so it got the revs to prime but reckon it restricts full constant overload, so I welded a bit on the butterfly rods arm to stop full throttle and ran them side by side so got same revs under load. I also noticed the spare shell sets look a very white colour where the failed shell was dark grey and just thought they had deteriorated laying about all that time. Now the un-governed block is very different in several places, instead of the one small brass plug for the governor rod carb side its got one large ether side and casting bumps filler cap side looks like other attachments for working the governors if it had any. The crankshafts the same as the one that was in use filled its sump with water and found that the metal had rotted away where the seal sat so swapping them was a quick fix, later skimmed a bit off the crank and slid a bit of stainless pipe over and further mods to take a modern seal wasn’t that easy, the old type was just a very thick carbon washer with a bit of rubber held tight against it by a spring still watertight in nearly 80 years. They are particular painful to start with the small rope pulley and light in weight both had there oil filler caps shared off as they lept up the pull-start rope and fell on there caps. was told were probably ment to run on the 100 octane so higher compression?.

[andyfrost]

Sorry David I can’t make alot of sense with that , there’s no way a 2A would rev to 4000 , it would simply blow up after VERY short time.Assuming you had both engines stripped out , did the ungoverned one have any sign of the internal govenor components.When correct they are one of the easiest starting engines , I’ve just finished one on a Howard Bulldog for a friend , starts first pull and runs like a clock.

Andy.

[davidbliss]

Yes they are very easy starting but these two really do take some bit to get over compression and best way is to turn them over by hand until at TDC then rap the rope and go for it, if you don’t they bite back, There was nothing of any governors on the one.
One was running last year when it was getting dry so just incase soaked round my bonfire, the other hasn’t for some years used to hook up both together to get a bit more pressure.
and yes the book says not to operate above 2,400 RPM well the one been doing over that for over fifty years. I’ll see if my daughter can do a video.

[sidevalve5]

Hi David,

Have a 1½” Alcon pump powered by the Villiers engine. Got it in the 1980’s and used it for irrigation. But then got sprinker rotor heads that needed a higher pressure (30 – 35 psi) than my original ones. The pump also started to take an age to prime. Fitted a new seal kit I got from Vulcan Water Pump Seals, it improved the suction, but still the pressure was not sufficient. Got another Honda engined Clark pump (26 meter head), but still the pressure was not enough. So did try to link the two together, but I only got a small increase in pressure. In the end got a Robin engine Koshin pump (30+ meter head), it performed well.

Took the Alcon pump apart again and found the engine crankshaft was pitted with rust. I think these indents allow a small amount of air to get past the seal and effect the pump’s performance. I was going to go along a similar line to yourself and sleeve the crankshaft. But without your skills I was going to use a hardened stainless steel shaft repair sleeve. Proposed to fit it over the shaft then grind off the flange. What do you think of that idea.

Decided I would swap the Koshin pump and fit it on the nearly new Honda engine, the Clark pump onto the well used Robin engine. Found that the crankshaft on the Robin engine had grooves on it where the seal was in contact with it. Also the Clark pump seal was not in the best condition, so replaced it with one from Vulcan. Now have two pumps that perform well, although the Koshin is the superior one.

Dropped on some Evenshower Oscillating Spraylines and these operate at a much reduced pressure. In fact I now use the Clark pump and only need half revs from the Robin engine. The original pendulum operated oscillation valve was worn out and leaked everywhere. So make another from a pair of ¼” ballvalves. But the operation was too stiff for the pendulum, freeing them up caused leaks. Have just spent Easter Sunday making a new valve with a 3 port L configuration. Have high hopes of success and will be starting irrigation this week. It needs it too, in my part of the world near Evesham we have not have any significant rain for 6 weeks or more. Am going to put a pressure gauge on the irrigation system to see exactly what pressure the spraylines need. They are very satisfying to see operating, gently and quietly going from one side to the other in true 1950 – 60’s market gardening style.

Best wishes,

Grahame

[davidbliss]

The Villiers engined pumps were the 2” inch JAP’s 1.5 inch and I just had a bit of seamed stainless pipe, don’t think the engine shaft was more than 4 inches, so a reamer took the bumps out, the new ceramic seal worked similar to the very simple carbon disc, bit of rubber with a spring to push those bit up against the brass bit the pump body, it wore very little over all those years, its amazing it often would instant pump after standing overnight without the water running back so the clack valve done its job, in the very dry times it help water the stock maybe a field away from the farm it often lived out for a month or so just with a old tin bath hung over drawing water from a pond. It once ran a week every day flat out emptying fire lagoons on a airfield as they were being taken out. and the one pump has a pressure gauge on it and rarely did it better the red line of twenty.

[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

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