Can you run a lawnmower engine on its side?
Matt asked:
I want to build a motorbike and i need to know if you can run it on its side. I’ve heard that you couldn’t, but I don’t know.
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I want to build a motorbike and i need to know if you can run it on its side. I’ve heard that you couldn’t, but I don’t know.
September 7th, 2009 at 3:03 am
Probably if it is fuel injection.
September 7th, 2009 at 7:08 pm
You can… I wouldn’t recommend it though
September 11th, 2009 at 5:24 am
Most lawn mowers use carburetors, and a rotary lawn mower would have its carburetor air camber horizontal to the ground. It won’t work if it is vertical. Also the oil pump and oil reservoir are set up to operate with the crankshaft vertical. I would suggest getting a horizontal shaft motor which are used on reel lawn mowers.
September 14th, 2009 at 2:36 am
is it a small one cylinder engine? less than 7 HP? No, You could easily move the carb to keep it level, but the lubrication system in simple vertical shaft engines will not allow you to run it more than 20 or so degrees from level. The oil will simply slosh to one side and most of the engine will be without oil. For this one you will need to either find a gear box that will allow you to keep this engine level, or you will need a horizontal shaft engine. Sorry man.
September 15th, 2009 at 5:39 am
Also lawnmower engines have an aluminum flywheel and rely on the blade for flywheel action and will not run well with out the blade.
September 16th, 2009 at 11:59 pm
The problem with all engines are the forces applied to it due to gravity. This means the oil and fuel will run to the lowest point. This means that if the engine was not designed to be layed on its side the oil will run from the crankcase into the cylinder. The gas in the carburator will also run out unless the carburater is remounted with special plumbing to get it level. If your engine is a 2 stroke (dry crankcase, oil lubrication added to the gasoline) then you will only have to figure out how to mount the gas tank and carberator.
Now there are other methods to get around this. I am assuming that your problem is that you have a vertical shaft motor and need to get the output shaft axially aligned with your rear axle so you can attach 2 gears and a chain.
One solution is to find a small engine with a horizontal outputshaft. Then follow the manufacturers recommendation for max allowed install angle off of vertical. This requires buying another motor.
Another solution is to find a right angle gear box to change the output shaft without changing the engine install angle.
September 19th, 2009 at 10:06 am
If the design of the engine allows you to.
Generally two stroke engines will run at almost any angle if the carb is suitable. Chainsaws use pressurized jets to enable them to do so. The lubrication system is provided by injecting oil into the intake air flow which is then directed to the lower side of the engine and from there into the combustion chamber and this works well at any angle.
Four strokes are a bit more difficult. Wet sump engines will only work when the sump (and oil pickup) is at the lowest point. They can be made with external sumps (a common thing in motorcycles). Carburetters usually have float chambers that are sensitive to the angle but can be made to work at other angles. Fuel injection generally has little problem with the angle.
September 20th, 2009 at 4:16 pm
No, you cannot.