One lunger to run vacuum pump?

[Paul VT]

Has anyone ever tried using a one lunger engine to run there vacuum pump? These will run along time on not much fuel. Would take some pulleys to get the right ratio.

[madmapler]

A lot of guys who cant get electricity use 1 cyl. engines for power. I use a 79cc.(2hp.) predator engine from harbor freight. Cost was $100 new. It sips gas. I run a rotary vein pump. Gas engines generally are governed at about 3500 rpm. Pumps generally run at 1750rpm exactly half so pulleys are easy to figure. You can buy a laser tachometer on ebay pretty cheap. This will tell you exact rpms. The only other thing I can think to suggest is if your pump is rated for a 2 hp electric motor then you should go with a 3 or 3.5 hp. gas engine. There are companies out there that sell gas powered pumps if you care to spend the extra cash.

[lew]

I believe he is asking about the old "hit and miss" engines. Never seen anyone use one, but sure would be cool. Not sure on fuel consumption, but your theory sounds feasible.

[maple flats]

If you do mean the old hit & miss engines, it would definately need to be protected from the elements. If I remember correctly rain and snow could get into the mix causing dependability issues.

[lastwoodsman]

I used one lungers (John Deere 1 1/2 hp) (international LA) to run my well at the cabin for years. Trouble is they are heavy to move and handle. Certainly they will run all day but unless you have a good supply of parts a simple modern small engine as described above would be preferable.


Woodsman

[madmapler]

I just assumed he meant 1 cyllinder. Thats what some call them around here. I personally have never even seen a "one lunger"thats still being used.

[Mike R.]

If referring to hit and miss engines, I have 1 1/2hp hit and miss engine, will run forever but needs constant attention to fill the oilier and keep the level up in the water hopper and tighten down the grease cups.

The major down fall of using one of these is if something breaks the time it takes to make or find a replacement part could be longer then the entire season.

Say the engine runs at 600rpm with a 18" flywheel (use a V belt and run around flywheel) and you need lets say 1500rpm at the pump the pulley on the pump will need to be about 7.25".

[Paul VT]

Sorry. Yes I did mean hit and miss type. You are probably right about all your concerns. It was a thought I had becuase I know how little fuel they use. I am surprised that no one has tried this before. :)

[Mike R.]

From what I see the hit and miss uses more fuel than throttle governed.


Under a full load condition, both types of engines are basically operating wide open and there should be no real difference. Under a no load condition, the throttle governed engines fire every other revolution, but they do so with less consumption of fuel each firing. The hit and miss may not fire every other revolution, but when it does fire, it does so with a full throttle equivalent charge of fuel.