Hello,
My wife bought me two Nelson 422 motors for my birthday. I would like to know the proper setting as far as shims go. Also I have heard that the APC Carbon prop is now legal, how good are they. I would GREATLY apprecaite any help. If it matters, the planes they are going in are Miss Ashley's.


Jorge

I would run it the way it was sent to you.. If you wish to measure it, I think most people run about 196(liner) and 16(total head clearance).......

Bolt it in to your plane then buy the APC 7.4 x 8 D1 carbon prop, check balance and bolt it on and run it. It's that simple. The APC prop is excellent for those of us who don't enjoy the whittling and tinkering of prop technologies.

RPM should be approx 23.5 - 24,000

Go have fun. Yee-ha.

Randy S.

Thank you for the help, I just realized I put this in the Q-500 forum and not the 422 forum. Thank you for the information, I like the idea of not carving the props.

What plugs should I run and do you need to change them every run?


Jorge

Jorge,
For the Nelson engine, you can run either the Nelson standard glow plug or the heavy duty. If your engine is setup as received, you needn't change the plug after every run. The heavy duty plugs will last longer than the standard plugs but some claim the standard plugs are easier to "read" after a run. ie. easier to tell whether you should make changes to the needle setting or the head shims.

However, at this point in the interest of simplicity, just get yourself 6 or 8 heavy duty plugs and, once again, go run it. I routinely put 10 or more runs on one heavy duty plug before it needs changing. Again this depends on how hard you are on the engine in terms of the needling etc. If it glows after a run and it's not too distorted go ahead and run it again.

I am running .196 on the sleeve and about .013 on the head and I usually fly at locations 1800 to 3500 feet above sea level.

Randy S.

Hi Randy,
Thank you for taking the time to answer my questions. I have one more. Sine I have no experience with the Nelson 422 engine, what is the best way to needle it so I don't hurt it. I have raced Nelson Q-500 engines, but I have heard the 422 engine is a different animal all together.

By the way I went to the H&M site and those are beautiful planes. I wonder why you don't hear more about them?

Jorge

Hi Jorge,
Regarding H&M planes (Miss Candace), stay tuned for the JR Gold Cup in Phoenix. There will be several H&M Candaces competing. You might be surprised......

You don't hear more about them because they are mfg'd in Canada and only beginning to become a serious rival to the Miss Ashley II, Dago, etc.

Regarding needling the Nelson 422 engine, everyone has their own procedure however I will share mine with you.
1) Ensure that you start out a little on the rich side so that the motor does not 'peak' right away. I always come up to near peak from the rich side of the band. I usually back off the needle 1/4 turn from the last flying setting.

2) Choke the engine while spinning with the starter. Choke either by plugging the venturi or the muffler exhaust hole. Remove choke when the engine begins to fire.

3) Let the motor warm up for 5 or 10 seconds while you clear away your starting gear. I walk around behind the motor and set up my tachometer.

4) Slowly turn the needle in about a 1/4 turn to obtain a nice smooth two cycle, "on the pipe", sound. With the APC 7.4 x 8 cf prop you should be somewhere around 23,000 rpm.

5) I NEVER peak the engine with the needle. At this point I pinch the PRESSURE line for about 1 or 2 seconds. This starves the tank for pressure and SLOWLY leans the engine. I prefer this over pinching the fuel line which immediately starves the engine for fuel.

While pinching the pressure line I watch my tach to see an increase of about 500 rpm up to peak (say 23,500). Release the pressure line and watch the tach fall back 500 rpm. If you get more or less than 500 rpm increase or decrease, adjust the needle accordingly and then pinch the pressure line again. Repeat until you get the amount of "off peak fall back" you like.

Go fly it. With this method I have never hurt a motor and I rarely damaged plugs. As you get to know your motor and airplane setup, you can experiment with the amount you back off from peak. If I get ambitious I will back off only 200 rpm or so. Now, a lot of this depends on the prop you are using the load / unload characteristics. This will vary greatly for wood props. From my experience, the method I described works well for the APC prop.

Good luck,

Randy S.

I would like to know how is it that you got your wife to buy not 1 but two midget motors. I must be doing something wrong!!

Mikey D

Hi Randy,
Thank you again, you have been real helpful, and this will get me going. Do you go to the AMA Nats? If you do, hope to meet you.
As far as the wife buying me the motors, yeah i am lucky for sure. I had to quite flying altogether for a few years while I needed to work 2 jobs to make ends meet while she went back to school. She is now a full fledged dental hygienist and just got a nice raise. This was her way of saying thank you : )

Jorge

No problem. I'm only passing on what I have learned from others and what works for me.

No, I have not been to Muncie for the Nats but I want to go some day. This would be my dream contest. Roy Andrassy and Harold Sattler from our district go almost every year and they always have fun. Roy calls it "Racing Boot Camp"
Some day I will be there.

My sites are on Phoenix in February for the JR Gold Cup.

Cheers,

Randy