AERMOTOR 8 CYCLE PUMPING ENGINE

AERMOTOR

The Aermotor is an unusual and interesting engine.
It is described as an 8 cycle engine which means it only fires every 8 revolutions instead of the usual 4 or 2. This is achieved by the the shape of the cam and the 4:1 timing gears. 


There is also a centrifugal governor inside the flywheel which will hold the exhaust valve open when the engine reaches it's operating speed. This means the engine does not fire very often and make an interesting model to watch.


These engines were designed to drive a water pump which would be connected
to one of the three tapped holes in the final gear. Different strokes could be chosen depending on which hole was selected.
The engine is in fact an engine and gearbox combined, the two final gears are not part of the engine function.
The engine has low tension ignition instead of the more well know spark plug and HT coil. This has a pair of contacts inside the cylinder head, where the spark plug would normally go which are pushed together and quickly opened by the action of the trip arm. A 12v battery is used and the coil is a simple single turn one. I am using a choke from a fluorescent fitting.


The Aermotor company of Chicago where best know for their wind driven pumps and are still in existence today. These engines could be fitted at the base of the wind pump tower and be used when there was no wind available.
In another application were a water supply was needed away from the house, the small fuel tank on the engine meant the tank could be filled up and the engine left running unattended, it would run until the fuel ran out which would be long enough to fill a storage tank with water pumped from the ground.


The model is half size has been very accurately scaled from a full size engine including all the detail like pattern numbers on the castings.
Scale flywheel diameter is 10 1/4 " but it could be reduced to 10" if necessary. This small difference would not be noticed.


I have castings and plans for sale.
The cost is £250.00 for the set of 12 castings and 57 sheets of plans and 18 pages of construction notes and photos. plus shipping which I can do worldwide.
The casting set now has the flywheel cast in zinc/aluminium. This material is nearly as heavy as cast iron so makes a good flywheel. It machines very easily to a good finish.
My original flywheel was aluminum and had a lead filled steel rim to give it extra weight.
This is not needed with the new one. 






Castings, not shown is the pinion casting.

TESTIMONIALS

Got my Aermotor running today, running on naphta, started on 3rd pull & ran fairly well, a little more adjustments and it should be fine. Very good castings, best instructions I have ever had, I am NOT a machinist & need all the help I can get." Steve, USA

"A very enjoyable project, I experience a lot of fun.
Today, the engine tested. Some adjustment problems, but it works nicely.
I am a happy man, thanks for all the good advice."Dirk, Belgium.

"I am very happy with the kit your workman ship is fantastic".
Cameron, Australia

"I  received castings this morning,  superb set of castings will read the build instructions later. They look to be the best set of instructions I have ever received for a set of castings."
Alan, UK.

"WOW I just received the Aermotor castings and your castings are among the nicest I have ever seen! "
John, US

"I have done a load of casting based engines and have a lot still in stock and your castings are as good as the best of them, very nice indeed"
John UK.