Got my Norvel 049 running

Theo, the reason the no go using the bladder is due to the stock needle valve. The threads are not fine enough and the taper of the needle is too great. I retro fit the Cox 128 threads per inch needle into my engines. If you happen to know any of the control line guys who fly combat you should seek a F2D needle valve assembly. This would require the stock venturi to be drilled out a bit but it would work far superior assuming the spraybar isn't too wide. You just can't get a good setting. A smaller prop will sometimes remedy that problem to a degree. I will use a 5x3 Cox black with the blades trimmed down to 3 3/4". Not a good choice for that plane. The smaller prop allows the engine to unload a bit on the ground providing you with a easier needle setting. When running bladder, tipping the nitro to 35% isn't a bad idea either as this keeps the plug from cooling off. I see the stock Norvel plug is still in the engine. The plugs themselves work well, typically though their lifespan can be short lived. If the engine is new, adding an additional head shim will extend the lifespan a bit until the engine gets some airtime on it.

One thing I see in your engine mount is the aluminum angle with the machine screws holding the engine lugs. Is the aluminum plate itself tapped for the screws or are they just through holes for your machine screws? I would highly suggest using loc-tite on the nuts as vibration will quickly loosen those nuts and they will fall off. I make it a common practice to use Nyloc nuts on engine retention screws.

One more thing, your tank works looks very nice. Solder looks good inside and out, you have my thumbs up. Nicely done. Ken

Hi Theo, all I can add is that it would be a good idea to use a dremel cutoff wheel and chop off the top section of that needle. That way your first inverted landing won't bend it.

Ken is of course correct, you must have a fine thread needle valve. The old Cox postage stamp backplates frequently had them. Especially the red ones. I wrote a how-to after Ken told me how to do it.

http://www.rcgroups.com/forums/showthread.php?t=1863251

This is a good discussion, and the inspiration for my above link:
https://www.coxengineforum.com/t2949-fine-thread-needle-on-norvel-s-and-similar-engines
Hope that helps.
Rusty

Hi Guys

Thank you for all the TIPS and help. I really appreciate it. I will consider changing some stuff once tested.

The wind was terrible this weekend.

Ken, the aluminium plate is just through holes. I will change the nuts accordingly as you suggested.

Thanks Guys.

Theo

Hi Guys, I have a question regarding my Norvel.

I am running a APC 5.7x3 cut down to 5x3. I am getting 17,000rpm.

I want to try and fly some stunts with it, so I understood that I should use a 6 inch prop.

So I tried to run a Master Airscrew 6x3 prop, but it looks like the norvel does not like it. I could only get like 13,000rpm.

Any suggestions?

Theo

I am not neutral here as explained in previous topics my experience with NV is, well, different than that of many of you.

A good COX TD049/051 will spin your 5x3 prop at >23k...mine, after 100+hrs runtime that a NV will never see, turns a 5x4 at 22,5k...so if you seek performance, dump the NV and go back to COX TeeDee

Unfortunately COX Tee Dee's are not that easy to come by now a days.

Theo Kleynhans wrote:Unfortunately COX Tee Dee's are not that easy to come by now a days.

Check e-bay, there are several New-in-box offers that you have a chance to win at around 75 USD or so..this is definitely value for money..I bought a NV Big Mig R/C 061 for about the same money in a new condition and it was disfunctional from moment zero...

Theo Kleynhans wrote:Hi Guys, I have a question regarding my Norvel.

I am running a APC 5.7x3 cut down to 5x3. I am getting 17,000rpm.

I want to try and fly some stunts with it, so I understood that I should use a 6 inch prop.

So I tried to run a Master Airscrew 6x3 prop, but it looks like the norvel does not like it. I could only get like 13,000rpm.

Any suggestions?

Theo

That doesn't sound right, the numbers are very low. What glow plug, numbers of shims and fuel are you using?
Have you had it from new or is it second hand? Some people use electric starters and bend the conrod, just something to check for...

Another, less serious, thing to check for is the throttle position. The throttle stop screw that is meant to stop the low-end will also hinder at full throttle. So try to peek through the screen to check that your "full" throttle really does give full throttle. This usually requires the stop-screw to be rotated as far as possible away from the throttle lever at full throttle. On RC planes I simply remove the screw completely and use the servo end limit to set full throttle.

Here are some of my typical numbers for a pre-revlite .049 Norvel on 10% nitro (stock muffler and RC carb);
APC 5.3;    21000rpm
APC 5.7x3; 18500rpm
APC 4.75x4; 20500rpm

(these numbers are roughly 500-1000rpm better than for the Cox 05RC)

Oh, I forgot to comment on Balogh's experiences...

There seems to be a problem with a late reproduction of the Norvel cylinders, i.e. the ones from the NV company. These are revlite versions were they somehow have screwed up the tapering of the cylinder (it has too much).

The engine in question here though is the pre-revlite engine made by Norvel, so there should not be any of those problems with it.

The Norvel .049 will/should be about on pair with a cox TD, while the .061 will be even stronger of course.

[quote="Surfer_krisHere are some of my typical numbers for a pre-revlite .049 Norvel on 10% nitro (stock muffler and RC carb);
APC 5.3;    21000rpm
APC 5.7x3; 18500rpm
APC 4.75x4; 20500rpm

(these numbers are roughly 500-1000rpm better than for the Cox 05RC)[/quote]
...and a good 1500 -2000 worse than a neked COX TeeDee 049...

but I am not here to defend any brand against the other...just look at the last sentence of the "Status" on my profile..

Theo, I have never used a Big Mig .049, only the .061 but the Master Airscrew 6x3 is way too much load even for it, and causes it to bog badly during loops, and never lets the engine spin up to its full potential even flying flat laps.

On my 7+ ounce Baby Streak, of which I've posted video here lately, I use an MA 5.5x3 prop, and it's at the edge of too much for load for my kind of flying. The only 6" prop I ever use on it(my .061) is an APC 6x2 because it's so slim it still allows the engine to rev up well into the mid 20s but pulls the plane slowly enough without bogging to fly on short 35' lines when I'm forced to fly on a small circle. I don't know if the .049 would do as well with it or not. Probably better with a 5.5x2 APC.

To get an idea of how the engine sounds with the MA 5.5x3 on long lines, listen to it in this video
This is also after many hours of running. Your engine is probably not fully run-in yet and will ger faster as it gets more run time on it.

https://youtu.be/oWjSp5C60Jw

I don't have any video with the APC 6x2.
Rusty

balogh wrote:
...and a good 1500 -2000 worse than a neked COX TeeDee 049...

I have never seen that from a Cox TD around here. I didn't intend to write cox down, if anything I usually defend both the Cox 05RC and the Queen Bee by actually using them on planes...

I still think that there is something "wrong" with your prop or the reading of 22000rpm on a 5x4 prop. No one else seem to get anything close to those numbers from a .049 engine, including myself...

My experience is that the .049TD is very similar to the Norvel .049 on props that are spun at about 20000rpm.

Surfer_kris wrote:

balogh wrote:
...and a good 1500 -2000 worse than a neked COX TeeDee 049...

I have never seen that from a Cox TD around here. I didn't intend to write cox down, if anything I usually defend both the Cox 05RC and the Queen Bee by actually using them on planes...

I still think that there is something "wrong" with your prop or the reading of 22000rpm on a 5x4 prop. No one else seem to get anything close to those numbers from a .049 engine, including myself...

My experience is that the .049TD is very similar to the Norvel .049 on props that are spun at about 20000rpm.

I tached my TeeDee051  with Hobbyco-s tach and measured around 22k on the ground...independently from me 1/2A Nut also measured it on my vid posted on youtube and measured the same speed (see on page 2 of this topic:https://www.coxengineforum.com/t7341p20-tee-dee-performance-crank, posted by 1/2A Nut on November 1 2014,, stating:... Your vid 21.6k to 22.3krpm most times level and 23.9k in best dive
... )

The prop I have is unmodified COX Thimble Drome 5x4 sold by COX International. This weekend, weather permitting, I will fly the Skorch (powered by a COX TD 050 R/C) and my Toucan (powered by a Tee Dee 051  with exhaust throttle ring) and will make a vid with my phone on the tach on ground to show you the numbers...I only say what I have seen.

Yes, I don't think that you are fabricating data and I don't mean to accuse you of anything, it is just that those numbers are not making any sense to me. So something seems off with the reading or the prop size, to me, are you sure it is a 5x4 and not a 4.5x4 for instance?
If anyone else on this forum are getting 22krpm on a 5x4 prop from their TD, please feel free to chime in.

Admittingly I haven't flow a regular TD for quite some time now, I'll dig one out from the drawers and see what I get. In the meantime we can take a look at some test data from others. Here are some data from Xenalook comparing their cylinders to the original ones, all used on a .049TD engine and a 5x3 prop;

Here are 2 pics in advance:

The black nylon COX 5x4 prop sold by COX Int'l even today:


The 5D 4P sign on the right blade is well visible (if not, zoom in on it)

and the "culprit" TD051 powerhouse with 100+ hrs runtime on it. This is the old stock tapered piston/cylinder version, with stepped thin-wall cylinder featuring fantastic compression even after it has run the lifetime of several NV peers and is still alive and kicking:



And the flight video of the plane (seen on the second pic on a bit battered condition, but I have no landing gear as the field where I fly is tall grass and it does have an impact on the nose of the plane) where, if you have a smartphone tach application, even yourtself can measure the stated engine speeds, otherwise I will tach it on the weekend and post the results:

https://www.youtube.com/watch?v=PhVMZCJeos4

The top rpm in your table with 5x3 prop is 20k; the ground rpm of my TD051 with 5x4 prop is >21500 and even higher. With a 5x3 prop my TD051 woukld spin well above 22500 I guess. I do not use more nitro than 20% and less castor than 20%

The text under the youtube vid states I have 30% nitro in the fuel. This was certainly incorrect. The fuel I used in the flight was a pre-blended Pelikan FAI fuel (then still available in Hungary) with 80%methanol and 20% castor that I reblended to 60/20/20 with nitro. I blended 30% nitro only once, when I checked the max speed of my TD010 that as we now is a nitro-addict.

I tend to use moderately aggressive fuels because I trade performance in on longevity. Hence the 100+ hrs running time and as new condition of my TD051.

The prop looks like it has been cut at the tips?

No way, I am never butchering my props. It maybe a bit worn but certainly not too much because I regularly check the prop balance and never had to sand/cut from any of the blades.

balogh wrote:
And the flight video of the plane (seen on the second pic on a bit battered condition, but I have no landing gear as the field where I fly is tall grass and it does have an impact on the nose of the plane) where, if you have a smartphone tach application, even yourtself can measure the stated engine speeds, otherwise I will tach it on the weekend and post the results:

https://www.youtube.com/watch?v=PhVMZCJeos4

The top rpm in your table with 5x3 prop is 20k; the ground rpm of my TD051 with 5x4 prop is >21500 and even higher. With a 5x3 prop my TD051 woukld spin well above 22500 I guess. I do not use more nitro than 20% and less castor than 20%

I tached with a smartphone app the speed of the engine in the above youtube vid and measured 24,1k at e.g. 6 min 18sec into the flight:

https://youtu.be/LozDDu8vFEs

The flight video was shot with ambient temp 5C (January) when the air densitiy is about 10% higher than at 32C in the summer....

From those who still doubt if a COX TD051 can spin a 5x4 propo at this speed, I guess the next question will be whether my smartphone battery was properly charged?

Surfer_kris wrote:The prop looks like it has been cut at the tips?

If that's the 5x4 then they are made with rounded tips.
http://coxengines.ca/cox-.049-propeller-5-x-4.html

Run Cox Run!
I'd like to know what my Tee Dee .049 is turning with Microflitedude flying it on 25% Beta test Cox Super Power Fuel this past Sunday. Of course you'd have to average due to doppler effect. That's an MA 5.25x3 prop.

https://youtu.be/EKV9cDuHLJM

balogh wrote:

balogh wrote:
And the flight video of the plane (seen on the second pic on a bit battered condition, but I have no landing gear as the field where I fly is tall grass and it does have an impact on the nose of the plane) where, if you have a smartphone tach application, even yourtself can measure the stated engine speeds, otherwise I will tach it on the weekend and post the results:

https://www.youtube.com/watch?v=PhVMZCJeos4

The top rpm in your table with 5x3 prop is 20k; the ground rpm of my TD051 with 5x4 prop is >21500 and even higher. With a 5x3 prop my TD051 woukld spin well above 22500 I guess. I do not use more nitro than 20% and less castor than 20%

I tached with a smartphone app the speed of the engine in the above youtube vid and measured 24,1k at e.g. 6 min 18sec into the flight:

https://youtu.be/LozDDu8vFEs

The flight video was shot with ambient temp 5C (January) when the air densitiy is about 10% higher than at 32C in the summer....

From those who still doubt if a COX TD051 can spin a 5x4 propo at this speed, I guess the next question will be whether my smartphone battery was properly charged?

Balogh,

I am sure nobody is questioning your integrity. The accuracy of your phone app maybe, who knows? I think it's possible for a TD to turn a 5x4 at those speeds. I don't think any of mine can, although I haven't tried either.

I bet you have a real jewel of an engine that has all the right parts.

Agreed, Kris is a very good powerplant/airframe guy(as is Andras too) and a scientist. I have had great respect for his input since my early days at RCGroups when I knew very little about these toys I've been playing with since my childhood. He's one of the ones that patiently helped me learn.
Rusty