Hangar Flying => Hangar Flying => Topic started by: longez84 on July 01, 2010, 06:51:38 AM
Title: Actual Aircraft Performance
Post by: longez84 on July 01, 2010, 06:51:38 AM
My O-235 Longez Performs as follows at 1325 lbs.. All numbers are in Knots: Vso 65, Vy 85, max level flight speed at 5000' - 150 True. For comparision, please submit your Performance numbers. I'd like to see if i'm operating near the average. Thanks, Rob
Title: Re: Actual Aircraft Performance
Post by: rglos on July 01, 2010, 09:34:04 AM
O 235 L2C Same weight @ 3000 ft, 153 kts max 62x62 prop
Looks like we're pretty close
Title: Re: Actual Aircraft Performance
Post by: longez84 on July 01, 2010, 09:58:11 AM
Thanks for the reply. With a 62x72 prop, I am turning 2650 rpm at full power with my L2C. What are you turning for rpm?
Title: Re: Actual Aircraft Performance
Post by: LongEZDaveA on July 01, 2010, 07:19:55 PM
Vso - 57, Vy - 91, max speed level 170 KTs TAS at about 2850 RPM.
O-235 modified with lycoming 9.7:1 pistons, one Light Speed EI. Light Speed prop.
Title: Re: Actual Aircraft Performance
Post by: longez84 on July 01, 2010, 08:17:01 PM
Wow Dave, impressive. What is the pitch and length of your propeller?
Title: Re: Actual Aircraft Performance
Post by: LongEZDaveA on July 02, 2010, 02:44:00 PM
It is a little over 63" if I'm remembering right. I don't think Klaus gave a pitch spec. Just tell Gary Hertzler what RPM you want and he'll fix you up with a Silver Bullet prop. That's what I'd be buying if I was in the market today.
Title: Re: Actual Aircraft Performance
Post by: longez84 on July 02, 2010, 03:31:53 PM
Dave,
Does Gary Hertzler have a website? Did a search and came up with some EAA stuff but nothing for Silver Bullet Props.
Title: Re: Actual Aircraft Performance
Post by: LongEZDaveA on July 02, 2010, 09:58:27 PM
Email Gary at hertzler at yahoo dot com. Please tell him I recommended his props.
Title: Re: Actual Aircraft Performance
Post by: Tom on July 05, 2010, 10:45:54 AM
I have a plans stock VE with an O-200 with Hi Comp pistons, and lightspeed ignition. football style pant with the itsy bitsy tires. I plan on installing lambs and lightspeed pants this year,, hoping for another couple free mph!
At 7500' I can true out 190MPH turning a Teds 56x70 at 2950 rpm, at about 6 GPH I will get some shots of the panel in flight when I get home.
Title: Re: Actual Aircraft Performance
Post by: longez84 on July 07, 2010, 06:20:22 AM
Tom,
Thanks for the reply. Impressive speed with the O-200. I have heard about EZ owners turning rpm over redline, do you know how much over is ok?
Title: Re: Actual Aircraft Performance
Post by: longez84 on July 07, 2010, 06:23:57 AM
Dave,
Thanks for the adress, i've been in touch with Gary, I'll be sure to tell him that you recommended his props.
Rob
Title: Re: Actual Aircraft Performance
Post by: Tom on July 08, 2010, 10:25:04 AM
Hi Rob,
How fast can you turn you engine? Good question..
We turn the O-200s at Reno over 4200 RPM, but this is with all internals balanced. Failures are usually spun bearings due to low oil pressure when the oil temps are 260.
I think for a stock engine, lycoming or continental, 15% over shouldnt be a problem. Listen to your engine and see how it sounds. if it complains about revving high, dont!
Title: Re: Actual Aircraft Performance
Post by: go ez on July 09, 2010, 04:48:26 AM
If you have a digital tachometer, you can add 2% to the rated RPMs ie rated 2800rpm rises to 2856 rpm rated due to tacho's better accuracy.
Also bear in mind a wood prop is lighter than a metal, on which these figures are presumabley based. That reduces flange loads but not internal forces.
Regards
Title: Re: Actual Aircraft Performance
Post by: longez84 on July 12, 2010, 07:52:32 AM
Tom,
Wow, 4200 rpm's at Reno, amazing. I always thought that RPM's higher than 3000 cause problems with the propeller tips goig supersonic. Are you running a gear reduction in that application? Thanks for your input, very interesting.
Rob
Title: Re: Actual Aircraft Performance
Post by: longez84 on July 12, 2010, 08:01:44 AM
Go ez,
Thanks for the link. I do have the digital tachometer but wonder if the bulletin applies to me because I am running an O-235-L2C and that engine isn't listed. Interesting though when you note the inspection criteria and part replacements required following an overspeed. All the weaknesses are in the areas that you would expect, valve system, rod bolts, connecting rods, just like any race car engine.
Thanks, rob
Title: Re: Actual Aircraft Performance
Post by: Tom on July 12, 2010, 11:55:29 PM
Hi Rob,
The props we run are 55 or 54" Diameter,, so we dont really have the supersonic tip speed problem. Mind you we do have other problems with our props.. mainly resonance in the blades at the resonant frequencys (about 1200, 2400, and 3600 RPM) so we really need to be careful to stay away from these ranges.
Come out to Reno this year! I might race the eze if time permits.
Title: Re: Actual Aircraft Performance
Post by: longez84 on July 13, 2010, 11:26:10 AM
Tom,
I might just come out to Reno. What date is your class racing?