Actual Aircraft Performance

[longez84]

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

[rglos]

O 235 L2C
Same weight
@ 3000 ft, 153 kts max
62x62 prop

Looks like we're pretty close

[longez84]

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?

[LongEZDaveA]

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.

[longez84]

Wow Dave, impressive.  What is the pitch and length of  your propeller?

[LongEZDaveA]

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.

[longez84]

Dave,

Does Gary Hertzler have a website?  Did a search and came up with some EAA stuff but nothing for Silver Bullet Props.

[LongEZDaveA]

Email Gary at hertzler at yahoo dot com.  Please tell him I recommended his props.

[Tom]

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.

[longez84]

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?

[longez84]

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

[Tom]

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!

[go ez]

Take a look at this TCM document.

http://www.proaeroengines.com/docs/326C8B29E2A18977.pdf

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

[longez84]

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

[longez84]

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