RCU Forums

RCU Forums (https://www.rcuniverse.com/forum/)
-   Extreme Speed Prop Planes (https://www.rcuniverse.com/forum/extreme-speed-prop-planes-104/)
-   -   SUPPRISE FLIGHT REPORT (https://www.rcuniverse.com/forum/extreme-speed-prop-planes-104/5957261-supprise-flight-report.html)

rmenke 06-07-2007 01:43 PM

SUPPRISE FLIGHT REPORT
 
Guys:

Some recent experiences are interesting in outcome. At the clubs monthly race last weekend, there was a interesting fly off compairson of engines in the same exact airframe. A Jett 60 LX flown by a 30 something pilot against a 70 something flying a Webra 55. One heat does not tell you much, but after 3 heats on a fixed 600' two pole pylon course, some general results are reasonably valid. I built the Webra powered plane for practice, need lots of it. Any way, both engines on Power master 15%, same pipe, Jett stream. At all 3 diving starts, the aiplanes appeared to be near equal in speed. After 3 10 lap heats, the outcome was the same, Webra won. Darned thing turns a 9 X 10 apc around 18K, would probably burn up the Jett, it turns a 8.8 X 8.75 close to the 20's. I was shocked at this outcome as I am a die hard Jett fan, the 60LX now my favorite engine of all time almost dateing back to the big bang. And yes, if we exchanged pilots, the results may be different, but take my word for it, the kid is coming hard. My whole point here is not really the winner, its the fact that a Webra 55 can compete with the Jett 60 LX, most thngs being equal. Race speeds somewhere in 120 to 140. Airframe is a World Models Ava-star, wings built streight and cut down to 40" span, two bays off each side. Makes for a nice cheap practice airframe, will turn well and be much much faster than you would think. Outruns Q-500's with TT 40's or so, honest.

Next strange thing, recently broke in a TT 46 pro, as usual following manufacturers recommendations. 10% Powermaster with 4 oz. of extra castor. Was also using the same fuel can to give the Webra and Jett 60LlX some nice rich flight time. Webra and Jett seamed to thrive on the mix. Getting close to race day, flew the 3 aircraft on streight PM 15% with 1 OZ castor added. All seamed to enjoy the mix. Ran out of fuel, borrowed some PM 15% from Nephew. The TT did not care, the Webra just was not a happy camper, the Jett, a little change in bark and rpm. Same day, same tack, same everything. You engine guys can scream all you want, I will still will be running Powermaster 15% with 1 0Z caster on race day. Above all, ENJOY Your bro # 119.

daven 06-07-2007 01:49 PM

RE: SUPPRISE FLIGHT REPORT
 
Interesting, I would suggest trying other props on the Jett.

Mike Connor 06-07-2007 02:09 PM

RE: SUPPRISE FLIGHT REPORT
 
ThrustHP shows the Jett with more horse power with the #'s you gave. I am with DaveN, try a different prop on the Jett

Flyboy Dave 06-07-2007 02:20 PM

RE: SUPPRISE FLIGHT REPORT
 
I've been using Powermaster 15%, sometimes with extra castor for over 15 years
now. ;)

I don't buy 20/20 nitro fuel fuel with synthetic oil. I bump up the 15% PowerMaster
with straight nitro to get to 20%....

....I will not run straight synthetic oil in my engines....period. I do have two engines
that run on 5% PowerMaster, a Rossi, and an high compression ASP .91 two cycle.

FBD. :D

Destiny-RCU 06-07-2007 05:36 PM

RE: SUPPRISE FLIGHT REPORT
 
I think the LX needs more prop....From the reading i've done the 9x10 is a little bit much for the SJ.50. The 9x9 or a pylon prop like the 8.8x8.75" is within range for that engine....Now the .60LX is a different story it shouldn't have a problem running a 9x10...Maybe bob27 will chime in. I would like to hear about some prop tests and outcome.

Mike Connor 06-07-2007 07:08 PM

RE: SUPPRISE FLIGHT REPORT
 


ORIGINAL: Flyboy Dave

I've been using Powermaster 15% with extra castor exclusively for over 15 years
now....I have not burned an ounce of anything else.... ;)


.......I do have two engines
that run on 5% PowerMaster
......FBD. :D
I couldn't help it. :D

Kaos1 06-07-2007 08:46 PM

RE: SUPPRISE FLIGHT REPORT
 
Have the pipes been properly tuned to the prop/rpm? I just doesn't sound right. I've owned Webra's in the past, a good engine. Bought my first one back in '75 (not quite the Big Bang). Rossi, Picco, OPS, Enya, Novarossi, Super Tiger, and Cox over the years. Aspire to own a Jett. But I can tell you that if you don't have the pipe set right on any engine, you might as well pack up for the day.

Kaos1

bob27s 06-08-2007 10:27 AM

RE: SUPPRISE FLIGHT REPORT
 
I've never tried a 9x10 full blade APC prop. Who knows :) Might be a thinner blade than the 9x8 or 9x9 for some reason.

The key to the 60LX (side exhaust, gold muffler) is to ensure it turns about 18,000 rpm at peak on the ground. A bit below that is ok. Try what ever prop you like.

Roger, you didn't note what prop you had running. On the larger airframe like the Ava-star that might be a consideration.

The 8.8x9 q-500 prop works nicely on the 60LX.
A standard 9x9 works too.

If the modified avastar is that quick..... then you might be able to try the 9x9 or a 8.8x9.25 - just use caution with the needle setting.

Webra has always made a good engine. The W-55 is no exception, especially when set up with a good exhaust system.
He must be running the SS jett muffler if it is running in that 18K-20K range.

rmenke 06-09-2007 11:44 AM

RE: SUPPRISE FLIGHT REPORT
 
Guys: As usual, Bobs insite is amazing. Sorry I was not clear. The jett 60LX has the black SS pipe and runs 8.8X 8.75 as Dub wants. The Webra is running the 9 X 10 apc. The pipe (muffler) is a Jett stream red pipe designed for a Super Tiger, the closest thing I had in the nuffler box. I would have never come up with a 9 X 10 for this motor. I worry about anything past a 9 pitch prop on anything, and would not mount one on my Jett. The prop recommendation came from two of our go faster guys that usually are right on the money, as they were in this case. I still shake my head as the results in actual use just do not compute in my head either. Thats why I gave you a heads up, very very unsuual. Was sorta also looking for a pigon, like someone close to my area, who does not believe either the Webra story or the Avi-Star story, and want to run for pinks, either radar or pylon with somewhat reasonable airframes. Like your TT 46 powered Q-500. Common sense knows I would not have a chance. (bet?)


All times are GMT -8. The time now is 06:12 AM.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.