Hi all

I have brand new Magnum XL 61RFS that needs to be broken in. The engine will be mounted inverted in my plane.

Would it be better to break it in upright on a testbed or would it be better to break it in inverted in the plane?

Does the orientation of the engine during beaking make any difference?

Marcel

if you have the option to break in your engine right side up, I would do so. I believe they will break in far easier right side up then upside down. After you have run it though you can mount it inverted and it should be fine.

G'day

I have run in many engines in my time but I have never run an engine in inverted. Some have been mounted sideways or even at 225 degrees but never inverted (180 degrees).

The main reason I would not run in an engine inverted is simply that it is too easy to flood an engine when it is inverted and especially when you don't know the engine at all. A flooded inverted engine is not fun and broken conrods are a possibility if you manage to get a hydraulic lock and use an electric starter.

My most recent two new engines were a Saito 40 and an OS 81 alpha. The Saito is now mounted inverted and is running fine. I spent about 20 minutes running it in a test stand and then moved it to its small Tiger Moth and completed its running in in the air. The OS spent about 20 minutes in the test stand and then another 10 in the plane being run to get the tuning right before its first flight. In both cases, the time spent with the engine in the stand meant that once it was in the model, I knew how much to prime and I had no problems with starting or running.

So ...

I'd suggest you get to know your new engine in your test stand and when you are happy that you can start it easily and have it tuned, then put it in the plane and go flying.

Cheers.

Mike in Oz

You have been given good advice

If you can sideways maybe the best, The engine will not load up fuel at low speed ( diesel seem more prone to this). It makes a neat installation, done with the with pitts type, mufflers, regardless of a regular muffler or pitts type the muffler is under the plane, looks good on on a round cowl, plane stays cleaner no residue on side of plane. I have even done this on trainers you do not have the big cylinder in front of the windscreen , sure you have to slice the cowl but gets it away frome the typical trainer look too
martin

I would only break it in right side up only, as this ringed engine should be run very rich initially. I used to own a Magnum .61RFS 4C and it was a real sweatheart.

Hi guys.

Thanks so much for your input. I agree that running it in on a test stand will be better. I have a couple of Saito's but this is my first Magnum. Does not seem as refined as an OS or Saito so I will take some extra care in running it it.

G'day

I have had a few Magnum/ASP engines and have found that a percentage of castor in your fuel will help things. A number of people here in my club will not use any castor because they do not like the mess but they are also the ones who have had problems with seized engines. I use fuel with 5% castor, 15% synthetic, 10% nitro and 70% methanol and have found that the Magnum/ASP engines run fine on this. One that I tried to run on "Four Stroke Fuel" which did not have any castor ran hotter than when I ran my castor mixture.

Out club's "Specialist Engine Destroyer" has recently converted to using a bit of castor and has not managed to destroy any engines since. He is a convert.

Hi

Well, I usually use 15% nitro fully synthetic oil in my heli engines, and four strokes which up to now have only been Saito's.

But after reading the manual carefully, they also reccommend fuel with some castor in it. So I got some Omega 10% that I will use for that Magnum to break it in. if it runs fine on that I will stick to using it.

I would suggest running the engine for a while on a engine test stand first. You can adjust it and get used to it before you mount it inverted.
it is a lot easier if you have problems being on a test stand to iron them out with.
Then after you have it running OK, then move it to your plane.

I broke in this engine inverted....no problems at all....easy start...easy to adjust....easy easy...

No black magic here....you can run-in an inverted engine without problems.

I don't have a test stand, and it would be difficult to put it somewhere here...so I never break in the engines in a test stand..I would love to do so, but not possible right now.