jimo811

My Feedback: (17)

I have a new Nelson Quickee 500 40 size engine coming and I am wanting input as to what prop will pull my Great Planes Viper the best. I am looking for what brand and size you recommend. Should this combo be fast? Thanks for any help you can give. If you happen to have anything for sale propwise let me know too.

NitroWoman

You really need to read through the Pylon forum in the Q500 Section for lot's of info about the Viper. Me personally, I wouldn't put a Nelson on a Viper without ALOT of reinforcing.

daven

My Feedback: (1)

Only use APC Pylon props with a D-1 hub. I would suggest getting a decent tach, and make sure the prop is turning somewhere between 19,000-19,500 rpm. Play with props untill you get a peak rpm in that range. Back it off about 400 rpm and you should be good to go.

Here is a list of props that will work well with your combo:


8.8" x 8.5
8 3/4" x 8.75 W
8.8" x 8.75
8 3/4" x 9 W
8.8" x 9
8.8" x 9.25

They are ranked from least load, to highest load. A good start would be a 8.8" x 8.75 which seems to be the best all around prop for this engine. The 8.8" x 9.25 is the fastest, but unless you got a real strong Nelson, you will struggle turning it up to 19,000 and it won't completely get on the pipe. You can get these props from www.darrolcady.com or www.pspec.com or just go to the APC website (which is more expensive than the other sources).

Good Luck, let me know if you have any other questions.

I do agree, that the viper should be looked over extremely well and reinforced where necessary. The firewall has been known to be weak, as well as the wing hold down plates.

daven

My Feedback: (1)

and one other thing, make sure you got a pair of earplugs, and don't try to start it yourself. Get a helper to hold the plane.

bob27s

My Feedback: (19)

yeah, what they said

especially about giving the Viper a once over (and probably a twice over).

Also, I would not even attempt to run the engine would a conventional fuel tank. Tetra tank or Bubble-Jett tank is (in my opinion, considering the airframe, and this is your first time working with a nelson) mandadory.

daven

My Feedback: (1)

One question, what servos do you plan to use?

That plane / engine combo will be putting some strain on things, so consider what are called "mighty mini's" either hitec 225's or Expert SL 451's for Aileron and Elevator halves.

freebird1

jimo811, are you the one who out bid me on eBay. Anyway just curious.

I was thinking about pylon racing too. I went to a club just to see how fast the viper was. The guy had an OS 32 on the viper and it was very fast. turns faster than I can think. I would start with a 9x7 with the Nealson. Hang on because unless the weight has a difference you will be smoking. I would take Nitro Woman advice and reinforce a lot.

Good luck
Freebird

NitroWoman

Your Nelson won't like the 9x7 very much. Use Dave's recomendations.[sm=thumbup.gif]

StregaFlyer

Don't put a 9x7 APC on a Nelson.. Get a Pylon Prop with the correct hub.. With as many RPM's as the Nelson turns, that 9x7 will have a good chance to come apart.. All of the sizes Dave recommended work great on the Nelson..

Ed Smith

jimo811

Do not use a regular plastic prop of any make on this engine. If you do you very likely will end up wearing it! Listen to the advice of those that race and use the engine. Dave told you what props to use. APC developed the props with D1 marked on the hub specifically for use on high revving racing engines. If you use any other make of plastic/nylon prop you are asking for trouble.

The Nelson and Jett racing engines are not anything like a regular sport engine. If you have never operated a high performance engine then get some help/advice from those that have. Do not listen to those that have not!

Ed S

Ed Smith

jimo811

If this engine is new it will need breaking in. There is a correct break in procedure for this type of engine. I will not get into that argument here. Go to the Jett engineering website the procedure is described there.

If you follow the usual "Internet experts" advice of slobbering rich, you could break it on it's first run.

We are trying to save you a lot of grief here.

Ed S

bob27s

My Feedback: (19)

These are the Jett QJ-40 instructions (as Ed mentioned). By enlarge, they will apply to your Nelson Q-500 engine as well.

http://www.jettengineering.com/tech/techqj40.html

As all have warned..... use only the APC D-1 series pylon props on that engine.

My personally suggestion...... if you are just sport flying this plane, install a 8.8x8.5 prop on the engine.
It will be faster than anything you ever imagined, and setting the needle on the engine will be effortless. Also, if the engine is new, the prop is great for break-in.

pdxpaul

My Feedback: (1)

A 9x7 would be a good prop for a sport 40/46 on your Viper, and be plenty fast. It's a good idea to mount such a motor on new quickie for some trim flights, before mounting the Nelson. Paul

jimo811

My Feedback: (17)

I sure do appreciate all the info/input from you guys. I had previously been flying this viper with a lowly OS 40 FP engine on it, and it was fun. We bought several of these to get into racing at our club, but interest seems to have faded away. I ended up getting a wild hair and wanted to see just how fast this Viper could go, and found a brand new Nelson engine that I thought might help me find the answer to the how fast can it go question. I've been flying for some time, but this type of thing is new, so I do thank you again for your help. I will be looking to buy some props, bladder tank, and filler to go into this Viper to get the most out of this combo. If you have extras, let me know, and keep the suggestions coming. Thanks.

Jim

pdxpaul

My Feedback: (1)

That's good you have some stick time on the Viper. You originally asked if the combo will be fast. Well, I suspect with an fp40 on the nose, you are in the 90 mph range. An average BB sport 46 would be in the 120 mph range. A noticeable increase over the fp but you likely would have no problem adjusting to the increase. The Nelson will put in you the 160 mph range (that's a legit 160, not a fish story, and a sizeable jump in speed). For the inexperienced, the life span of airframes at such speeds can be short. Paul