Thorp Air Command - T18.net

I just bought 8JS.. a great flying Thorp... I had a vans RV-4 for a couple years, enjoyed that, sold that... now I have the T-18 and I love this thing!
Mine's got VGs..stall strips..all the goodies.
I'm shy about the prop, cutdown M76, I am thinking about going Catto or Whirlwind in the future.. any suggestions let me know, I have read and heard great things about both. Anyone else still flying with this type of prop here, and would you say it's all good to fly on the M76 or should I consider swapping it out asap?
8JS has an O-320 with 10:1 pistons, probably putting out between 160-170hp...all great compressions and very nicely maintained.
I have been thinking about buying a Thorp for years, I am glad I did..



Jenn (8JS)

Congrats, Jenn! I’m sure you will enjoy that bird for years to come.
Cubes

Congrats! I'm curious to hear your flight reports with the stall strips installed. You have a good looking plane.
Here is a link to the SDR list:
http://thorp18.com/index.php?option=com ... Itemid=125

This is clipped from the SDR (Service Dictated Revisions) page for our airplanes:

5. Cutdown Metal Propellers- If your airplane has a cutdown metal prop, especially an M74, replace it immediately. The M74 will fail (every time ), usually with a low number of hours. The M76 is supposedly "safe" for being cut down, but should also be viewed as a risk, especially if it has not been thoroughly tested by a qualified prop shop. Newsletter 79 has a lot of data on these props. If you are looking to buy a new metal prop, check with http://www.Sensenich.com for new props that are designed for T-18/S-18 engines and flight speeds. Also see NL 47. Recommended Sensenich wood props: W66LM for 125-179 hp, W68LY for 180 hp. (Note: These may no longer be readily available.)

Congrats Jenn, welcome to the Thorp family.

I have the Whirlwind ground adjustable prop on my O290 powered aircraft and I'm loving it. I gained 5-10 MPH at the same power vs the wood prop that it replaced. Gary Jacabsen has one on his O320 airplane. I don't think that you can go wrong with it. Up side you can tweek the pitch to get the climb vs cruise performance that you like.

enjoy

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Bruce Finney
N18JF T-18C #262
Yelm, WA USA

Congrats Jenn! Beautiful plane!

I also had an RV, a "3". Great aircraft, but I find the Thorp much more sturdy, less twitchy. I put the Sensenich ground adjustable on mine, and love it.
Congrats!!!
Stan Markus

Whirlwind here on my 0-290 - I can't believe how much faster the Thorp is over the RV's - I see guys selling 6's and 8's with 360's and only claiming 175mph, I get 190mph all day long out of 135hp.

I would not worry about the prop on that plane, it's the one and only FP metal prop 'approved' for the Thorp. That's a good solid Thorp you have, if I had the need for another I would have snatched it up myself!

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

Thank you so much everyone! I'm beyond excited to have this awesome Thorp and I definitely look forward to many years of adventures with 428JS. I will look into the ground adjustable props... it would be nice to be able to fine tune it to what works best with the bird. For now I may go ahead and stick with the M76 until next year...
Sorry about my late response.. I have been "out of office" for a week...
I will report back on the results with the stall strips in a while, they are taped on for now and when I get them just right I will do the permanent installation.

Thanks again, have a great week everyone!
Jenn

Gotta ask, how the heck are folks getting 190mph (165ish knots) on an 0-290? Best I can manage is 150 knots, usually plan for 145 unless I push the throttle through the firewall. 78WG is sporting a 0-320 with 160 hp and a 3 blade Catto. I can out climb an RV4, and barely outrun it (maybe 5 mph faster), but can't imagine where folks are finding another 15 knots in the performance envelope, but I seem to be in the minority.

Welcome to the Thorp club! Hope to see you at Oshkosh.

-Andy

Its been a long time since I had the 0-290 on my plane now, but I seem to recall I was seeing anything from 120-140 knots IAS range in various cruise settings. I had a wood Warnke prop. Its hanging on my wall now.

I’m not aware of anyone claiming 165 kts from an 0-290. Where are you seeing this? I will say back in the day John Shinn was clocked at 198 (0-290) during the race at Oshkosh, of course BC Roemer was clicked at 218 (0-360) that year too. So it is possible but not typical. An 0-290 on its best day is a 165 mph cruise aircraft.

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

o-290 with whirlwind prop WOT

Fraser ferried it from CA and got similar results:

http://thorp18.com/thorpforum/viewtopic.php?f=46&t=8289&p=19573&hilit=ferry#p19573

first that's wound up to almost 2700 rpm ...
second that's one of JT's 0-290's 140 + hp
third .. pretty sure there's some tailwinds to consider.

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

Yep - WOT is how I fly in cruise, 190 is TAS not GS - If I understand correctly winds do not affect TAS.