Reply To: Ex Air ministry Alcon Pumps

[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?.