Engine position

I have just ordered a Saito 4 stroke for my 1/6 Cub.
Is there any reason I shouldent position the engine inverted. This would
give a more scale look.
However I do notice most engines are mounted on their side.
Thank you
Carl Anderson
Delta B.C.
Can.
Reply to
carl anderson
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Watch out for flooding and "hydrolock". That's when the fuel completely fills the combustion chamber. When you try to spin it with an electric starter, you stand a chance of bending the con rod. Dr.1 Driver "There's a Hun in the sun!"
Reply to
Dr1Driver
You can have more problems with fuel flow and flooding if you mount the tank too high. Many times, inverted engined end up with the carb well below the tank. You can eliminate most problems by installing a regulated fuel pump, but moving the tank to the right height is the best solution.
Another problem is over priming and getting hydro-lock. Too much fuel in the cylinder can cause a bent rod if you crank it hard.
-- Paul McIntosh
Reply to
Paul McIntosh
I have definetly decided not to install my precious Saito 4 stroke upside down. Maybe it can be done with two stroke. Thankyou very much for the info Paul and Dr1 Carl.
Reply to
carl anderson
Just about all my motors are mounted inverted, 2 and 4 stroke. Don't make a hoot of difference. It does not hurt to have the tank CL a bit lower than normal so as to discourage flooding at rest. Gord Schindler MAAC6694
Reply to
Gord Schindler
To prevent flooding, it would help to keep a hemostat or other clamp on the fuel line until you get ready to start it. It might not be possible depending on how your cowl is set up.
John VB
Reply to
jjvb
Actually, mounting an engine upside down is more of a problem for a two-stroke than for a four-stroke. Most 4-strokes, including Saito, have valves in the head. This makes them difficult to liquid lock. Opening the exhaust valve will drain the engine.
Most engines run best with their tanks at the proper height. So paying attention to that is a good idea anyway. I routinely run Saito engines inverted without any problem. Don't prime before applying the starter, and you shouldn't have a problem. Hand starting also works.
Don't let the doom sayers talk you out of it.
Jim - AMA 501383
carl anders> I have definetly decided not to install my precious Saito 4 stroke
Reply to
James D Jones
How do you open the exhaust valve to drain the fuel? Turning the engine over backwards forces the fuel up the inlet pipe.
-- Paul McIntosh
Reply to
Paul McIntosh
Turning the engine over in either direction will open the exhaust valve on every other cycle. If there is fuel in the head, gravity will cause it to drain out the exhaust pipe. Sure, turning the engine over will also cause fuel mixed with air to be ingested on the intake stroke, but if the engine isn't choked, that is not a problem. However, it makes sense to use a metered glow lighter so as to ensure that the glow plug is lit before attempting a start.
Jim - AMA 501383
Paul Mc> How do you open the exhaust valve to drain the fuel? Turning the
Reply to
James D Jones
The exhaust valve doesn't open until after the power stroke, which is where the hydrolock will occur. If the engine is flooded, it is likely at the power stroke and not the exhaust stroke.
-- Paul McIntosh
Reply to
Paul McIntosh

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