Re: Official Endurance Run Time Thread - And the Winner is...

[1/2A Nut]

 Wow that was fun Congratulations GUS!!!!!!

GUS THE I.A.
High = 257 minutes
Low = 223 minutes

Per vid: time was 3 hours and 45 mins. / 225 mins.
I missed it by 15 minutes!!

Thank you Mark, CEF and the Sponsors for making this happen!

225 mins run time from 32 oz of fuel that is a average of 7 minutes and 3 seconds per ounce!

[KariFS]

Congrats Gus!

I was WAY off with my guesses, I figured the engine would run at least twice or 3x longer.

Looks like a product engine is quite a bit more thirsty than a Babe Bee (that I used as a starting point for my calculations), as a Babe would run for just a little over a minute with that average consumption.

Thank You Mark, Rene and Bernie for making this happen

[Admin]

Congratulations Gus!

I also want to thank Mark (batjac), Mark Diedrichs, Rene (Marleysky), Bernie (Cox International), and everyone who tossed in a guess. This was interesting!  


3 hours and 45 minutes of continuous screaming!    Mark, I bet you can still hear it ringing in your ears!

I somewhat figured my guess based on a Golden Bee's 2.5 - 3 mins average runtime on an 8cc tank.

[Levent Suberk]

Congratulations

[Levent Suberk]

Since I don't know the characteristics of a product engine cylinder, so I estimated my guess for a tanked Bee engine and also didn't consider % 35 nitro fuel. I missed it by 23 minutes

[getback]

Wow Congratulations Gus the IA !?!! That was Cool !! Thanks Mark, Rene and Cox International and of coarse Jacob ! If not for him we could not come together for this event . Enjoy the engine Gus = tell us how U did it .

[Mike1484]

A big thanks to all involved . That was fun and interesting as well .

Mike1484

[ticomareado]

How much NV fiddling during the entire run?

[Mark Diedrichs]

Way to go Gus!!!! Major Kudos to all who made this happen!!! Thanks for being here CEF!!! Mark

[--Oz--]

I missed it by 8 minutes. Fun contest, great win gus.

[GUS THE I.A.]

WOW!  FAR OUT!  THANK YOU!
Without such dedicated modelers that are present in COX ENGINE FORUM.COM, activities that are dreamed - up, and implemented, to promote fun and fellowship with the little engines, our world would be a lot quieter place! Ha ha! Seriously, the group here, brings out the best of the modeling world!
To be able to pop in, and discuss our latest concerns about our engines, and activities, shows just how close we are, and what we have in common.

HUGE THANK YOU to CEF, batjac (Mark), and COX INTERNATIONAL - Bernie, and RENE - Marleysky. And I cannot forget everyone who guessed incorrectly. (come on, I'm kidding)

Now - how did I do it? Do you remember the Flight Time Contest, which was held from June, 2013 to June, 2014? I retained the records for my flying of the TD .051, and each flight was made with a certain amount of fuel on board. Therefore, I knew how long my engine would run on a certain amount of fuel, because timing ceased when the engine quit, not when the flight ended. SO... it was a guess! An .051 TD probably consumes fuel at a different rate than a Reed Valve engine, so, I got lucky!

[aspeed]

Congrats on the win. My low time guess was around 12 minutes off. It was inside my high/low. I just went by the Norvel consumption rate of 8.25? min/oz and figured a smaller motor would be a bit less, and a smaller carb too. I think the reed makes it a bit less efficient, or the Norvel rating is just a guesstimate. I also am wondering if the needle valve needed resetting during the run. It is kind of the standard thing on the reedies, with the tanks anyway.

[roddie]

Congratulations Doug! It was fun; checking-in on this thread, to compare the guesses.. and read the banter. I'm thankful that we have this place of retreat in our forum. There's always something happening that makes it well-worth logging-in daily!

[--Oz--]

3 hours and 45 mins for 32 oz of fuel that is a average of 7 mins and 3.125 seconds per ounce!

Knowing the run time, the nitro and methanol content, prop and rpm, we could get a decent efficiency number on this motor?
Any takers doing the math?

I am guessing 10% efficient,,,

EDIT: I started a new thread for this topic:
https://www.coxengineforum.com/t13246-0-049-reed-motor-efficiency#170415

[batjac]

Gus, the engine is on its way!


I knew the engine wasn’t going to run as long on an ounce as I’m used to on my other engines.  I was figuring on about 6 ½ minutes per ounce.  So just over 7 minutes isn’t too far off of my initial predictions.

Remember, there were several things subtracting from the engine run time:
1) Higher nitro content
2) Hot, muggy air
3) Cam spring starter dragging on the crank
4) Stiff prop that doesn’t flex and de-pitch
5) Running on test stand so it doesn’t unload in the air
6) Tuned rich of peak
7) Sitting on a test stand getting heat soaked
8 ) Sub-par component tolerances in Estes produced components vs. genuine L.M.Cox engines (No reflection on Bernie)


Well, I don’t know about Y’all, but I had fun with this.  In fact, I was thinking that I would like to do this again with a .020 reedie engine.  Obviously, a quart would be much too long for a .020 engine.  But Cox did sell fuel in a ½ Pint can.  I wonder how long a .020 will run on a half pint?  Hmm….

Again, that’s an American pint.  If it’s a UK pint, it’d run all week, remembering the bottomless pint glasses from my Navy days across the pond….

The ‘Murican Mark

[dckrsn]

Way to go Gus!!!! Major Kudos to all who made this happen!!! Thanks for being here CEF!!! Mark

Hi, Biscus!
Bob

[--Oz--]

Almost 4 hours is impressive, I came across a electric wing doing 100 mile round trip on one charge, it was a 4 hour flight at 25mph avg with 1.75A avg on a 4S-7000 pack. I only bring this up as its roughly the same time as the 32oz reedy run.

32oz of fuel is ~1000g ~$10. 18650 x8 ~400g ~$40

Of course the reedy is wide open, where the bldc is ~40% thro, more info here on the 100 mile flight over the ocean.
https://www.rcgroups.com/forums/showpost.php?p=41483297&postcount=2058

It would be interesting to see the max distance 32oz of fuel could go. The z84 auw was ~600g, nitro might be ~1400g at take off.
Or make a challenge: Max distance on X oz of fuel.

Feel free to delete this post, no hard feelings.

[balogh]

To each his own


I would never buy an electric car and my current diesel will probably remain my last one..but no hard feelings towards Tesla fans...

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