Thorp Air Command - T18.net

I've had some local guys voice doubts about my speed claims. To put an end to it I took a video on my way up to Fort Worth yesterday. BTW this is with the Tom Hunter fuel pods hanging off the wings.

Enjoy.

[youtube]http://www.youtube.com/watch?v=QErcgkW_NSE[/youtube]

_________________
Lee Walton
Houston, TX
N51863,N118LW
KEFD

Lee,
That's amazing!!!! With an O-320 at 23 squared I indicate about 155MPH and if I firewall it I get 185MPH
Cheers
Graham (N444DD)

O and there's more!!

Here I am on the way home (I traded airplanes with Wendell Green)... same thing truing out at 200mph.

Note: N51963 does not have an autopilot. Look at how stable the Thorp is!

[youtube]http://www.youtube.com/watch?v=ELAa1jJHBkY[/youtube]

_________________
Lee Walton
Houston, TX
N51863,N118LW
KEFD

Graham,

23 squared gives you only about 110 HP out of an O-320 and 120 out of an O-360. Let the ponies run! Lee's observations are consistant with what I see on my fairly heavy 180 T/S-18.

_________________
Bob Highley
N711SH
SN 835
KLAL

Lee you must have a Tiger in the tank. < ESSO> J.P

*** admin posted for James Peran ***

_________________
Forum Administrator

Lee. I get the same speed flat out. At 2500 feet with 2800 rpm it indicates 180 kts witch is 202 miles an hour.. Wooden fixed pitch prop. J.P

*** admin posted for James Peran ***

_________________
Forum Administrator

All this talk about breaking 200 mph with an 0320 makes me extremely jealous! I've been trying to do this for two years, I cant reach 2500rpm and struggle to get 155mph with an 0320 that has about 150 hours on it and a Sensenich 70x77 (at any altitude)! anyone have a silver bullet fix? it seems I've tried everything.

Chuck

_________________
Chuck Kincer
Richmond, Me
575CK
KIWI

Chuck,
Sounds to me as though you're not getting full RPM. I have a Hartzell HC F2YL constant speed prop which only give me about 2600RPM static on my O-320 D2A. That's 100 RPM below max allowable. I guess that I'm not used to running engines at full power in flight but I think I'll go see what I get at full power max RPMs. Put's the fuel flow up to about 10GPH. Maybe we've both got prop problems. Graham

Chuck/Graham,
Both of the airplanes above are 180hp/with CS props. That being said, I frequently fly with David Read and his 150hp 0-320 Thorp and he has no problem keeping up with me, in fact there are some days when it's a struggle to catch up to him!

When I first purchased my airplane it was a 180 mph max airplane. I reworked the baffles and tightened up the cowl around the exhaust and instantly gained 10 - 15 mph.

If there were a magic bullet I'd say it's cooling drag and the fit of the cowl.

Lee

_________________
Lee Walton
Houston, TX
N51863,N118LW
KEFD

Found this on a Barnstormer's posting .... this is a 150 hp RV-6, in a slight decent, running 2500 rpm. Look at the airspeed indicator.

Don't feel bad guys ... the '200 mph RV's' aren't doing any better than 150-155 mph either!

_________________
Lee Walton
Houston, TX
N51863,N118LW
KEFD

Run it in the yellow arc!!!!!

Check the RV's ball. No airplane will go very fast sideways. I do notice several of the pictures have a couple of hundred FPM decent to help the speed. Would like to see a GPS speed averaged over a "box" of headings.

_________________
darylat8750ft

In the RV's case I think the uncoordinated flight and the 100 fpm decent cancel each other out ...

If you watch the T-18 videos they're both in level flight. Although there is a moment where 51863 puts itself in a slight decent and then corrects itself (hands were off the stick), I let that happen on purpose to demonstrate the Thorp's positive stability. As far as a "BOX" goes .. the two Thorp videos were taken with an hour or so of each other on the same day, on the same route of flight, Red was heading North and Blue was heading South. If you look at the GPS on each video they both say 170kts +/- a kt.

_________________
Lee Walton
Houston, TX
N51863,N118LW
KEFD

I must have had my head in my armpit. I didn't note that they were videos. Very impressive.

_________________
darylat8750ft

My RV-6A is o-360 with Vans Sensenitch prop at Cruise 2350 my airspeed is 165mph if I turn the revs to 2650 Im at 197mph. My mouse motor T-18 is 2300 at 156mph indicated I have never down flat out. Both great airplanes.