Guys,
The World Models Spitfire that I'm putting together of course calls for the engine to be inverted totally. It would stick way too far out of the cowl any other way. I will be using an OS FX .61.
I have been told that this is fine, but engine may have idling problems from being inverted. I have also heard that sometimes fuel can build up and lock the engine up, and if it is turned over, it can badly damage the internal parts.
Some have told me that because I am using a quality engine that is a newer model, the above will not be an issue.
Can anyone tell me what to expect? Any advice/tips? Thanks.

I posted the same Q a week ago. I think everyone is tired of arguing about it. Expect, from my experience, flameouts at the most inopertune time.Good luck to you too!
d

I have an older OS 61 inverted in a Zen 50, have to "burn off" the glow plug b4 every start. Get to much fuel up in there. Other than the starting issue not had a problem

ever considered starting it inverted? by that I mean with the engine cylinder up? it works better.
d

Just a thought. Almost every patern plane has an inverted engine

i have an inverted .60 in one of my birds, it's much easier to start with the left wingtip resting on my foot, and the right tip in my left hand (ala pylon racers i've seen), i put a 4 stroke plug in it, and it idles very low, somtimes it won't quit when i cut the throttle the whole way, just keeps chugiing for a bit, like an old beater car....

never had a flameout since i put in a 4 stroke plug, but i've run out of fuel more than onece

Consider adding a Cline regulator and you will not have any issues running the engine inverted. No problems with it loading up. No problems with flameouts.

Coomarlin,

Where can you get the Cline Regulator? Is the regulator a metering device?

Thanks for any info you can provide.

Vprpilot

I have an OS 46 FX in an Aresti. It took a bit to get the low end needle right, but after that it worked fine. The proper needle setting seemed to be a little touchier with the motor inverted though.

Larry

If you mount your tank so it's center line is in-line with the spray bar, you won't have any problems. This holds true no matter what direction the engine is mounted.

John

All my four strokes are mounted inverted without a single starting or idling problem. Each one took some time to get the low end needle dialed in, however. I basically leaned out the low end until the idle speed only dropped slightly when the glow plug igniter was removed. I also made sure the engine can idle for a couple of minutes and doesn't quit when I abruptly advance to full throttle. I don't touch the low end ever again once the "sweet spot" was found. The 2 cycle engine will be more tricky to tune the low end. I had a 2 cycle engine mounted inverted once a while back, and it was a real pain to tune the low end and to get it to start.

Need website address for cline's regulator..thanx

You can get the regulator directly from Cline at the following address:

Cline and Associates

Make sure the tank centerline is level with the spraybar. Adjust needles with tank HALF full. You'll be fine, watchout for flooding.

New engines hate to be inverted. An engine with lots of run time works good as it is less likely to flood out and idles better. Make a flight stand for your plane so you can start the engine with the plane upside down. It's worked for me! Paul

I've broken in YS (.60 2-stroke and 1.20 4-stroke), OS (.25VF, .48 Surpass, BGX) and Enya .53 4-stroke engines inverted without a single problem. All ran beautifully out of the box and were easy to tune. Install the tank properly, and the engine won't know, or care, what direction the cylinder is pointing.

just my .02 and experience,
John