RE: OS drops .32SX  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       



All Forums >> RC Airplanes >> Extreme Speed Prop Planes >> RE: OS drops .32SX Page: <<   < prev  1 [2]

Login
Message << Older Topic   Newer Topic >>
RE: OS drops .32SX - 5/18/2008 3:42:49 AM   
Jburry



Posts: 560
Joined: 7/12/2006
From: Cape Spencer, NB, CANADA
Status: offline 		Yup, it's amazing what we can do with 3 moving parts, isn't it? I've been flying RC for all of 3 years, but I've spent 2 decades playing with the engines on benches. Fascinating little jewls, cranking out amazing horsepower, and still living real good lives. Hell, how many do we actually ever manage to wear out? 10, maybe 20%?

The rest die of abuse and impact.

J

_____________________________

Revver Bro. #220

(in reply to combatpigg)
       Post #: 26

RE: OS drops .32SX - 6/26/2008 9:01:44 PM   
Strykaas



Posts: 4107
Joined: 3/21/2003
From: Paris, FRANCE
Status: offline 		$190
Same mounting holes as the .25 fx, 10 g heavier than the .32sx.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXUYR8&P=7

_____________________________

ProBro #2077
http://image2-0.rcuniverse.com/e1/forum/upfiles/57402/Nl29490.jpg

(in reply to Jburry)
       Post #: 27

RE: OS drops .32SX - 6/26/2008 9:45:02 PM   
mmattockx


 

Posts: 2205
Joined: 4/28/2005
From: Calgary, AB, CANADA
Status: offline
quote:

ORIGINAL: Strykaas

$190
Same mounting holes as the .25 fx, 10 g heavier than the .32sx.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXUYR8&P=7


Wow, the price sure went up along with the displacement...


Mark

_____________________________

Waco Brotherhood #4

(in reply to Strykaas)
       Post #: 28

RE: OS drops .32SX - 6/26/2008 11:01:59 PM   
Sky Dart1



Posts: 48
Joined: 7/13/2002
From: Villa Rica, GA, USA
Status: offline 		Everything in Tower's stock went way up this month.

(in reply to mmattockx)
       Post #: 29

RE: OS drops .32SX - 6/27/2008 1:52:17 AM   
freakingfast


 

Posts: 809
Joined: 1/3/2005
From: mather, CA, USA
Status: online 		$190!! Wow, for that price get the Webra 36

_____________________________

When in doubt, give it full power. The smaller
pieces fit easier in the bag! Revver Bro #201

(in reply to Sky Dart1)
       Post #: 30

RE: OS drops .32SX - 6/27/2008 4:28:16 AM   
airraptor


 

Posts: 297
Joined: 1/26/2004
From: fairfield, CA, USA
Status: offline 		My jett 35 turns a stock apc 8x7 at 21,500-21,700 on the ground.

all you guys thinking your engine unloads in the air do you have proof. All the telemetry stuff is saying there not unload as much as we think.

JBURRY DO YOU REALLY THINK YOUR UNLOADING IN THE AIR BY 4,500 RPM??????

All the unloading I have seen is when using a pipe then taking off with the engine "not" on the pipe then once in the air coming on the pipe.

4 head bolts or 5 or 6 doesnt matter if the the head is installed correctly and designed for 4, 5 or six. as long as it seal who cares how many it has.

the supertiger .34 with red or gold mufflers will turn the same as the OS and with some work will turn stock apc 9x6 around 18,000 and the super tiger is lighter.



(in reply to freakingfast)
       Post #: 31

RE: OS drops .32SX - 6/27/2008 4:39:46 AM   
cncswiss1


 

Posts: 197
Joined: 7/15/2004
From: Indianapolis, IN, USA
Status: offline 		did anybody read the recommended props on the tower listing???!!!! 12-6? that's a 75 size prop not 35.. i'd like to see it lug that lumber, perhaps if it was converted to deisel

(in reply to airraptor)
       Post #: 32

RE: OS drops .32SX - 6/27/2008 4:58:59 AM   
Crazy4Flight



Posts: 2242
Joined: 9/15/2002
From: Milford, MI, USA
Status: offline
quote:

ORIGINAL: Jburry

Yup, it's amazing what we can do with 3 moving parts, isn't it? I've been flying RC for all of 3 years, but I've spent 2 decades playing with the engines on benches. Fascinating little jewls, cranking out amazing horsepower, and still living real good lives. Hell, how many do we actually ever manage to wear out? 10, maybe 20%?

The rest die of abuse and impact.

J



how about 1 moving part....
2 if you count the starter.

Attachments
Click to see fullsize image.
Click for fullsize


< Message edited by Crazy4Flight -- 6/27/2008 4:59:44 AM >

(in reply to Jburry)
       Post #: 33

RE: OS drops .32SX - 6/27/2008 5:34:15 AM   
Mike Connor



Posts: 1384
Joined: 1/10/2002
From: Tulsa, OK, USA
Status: online
quote:

ORIGINAL: airraptor

JBURRY DO YOU REALLY THINK YOUR UNLOADING IN THE AIR BY 4,500 RPM??????


I thought that sounded high too but jburry sent me his sound files (WAV) and at least Doppler said it was so. I have checked the in flight RPM of many airplanes using Doppler and they usually unload from 500 level up to 2500 RPM in a dive.

_____________________________

Mike
http://www.mikesrc.us/

(in reply to airraptor)
       Post #: 34

RE: OS drops .32SX - 6/27/2008 3:08:49 PM   
Jburry



Posts: 560
Joined: 7/12/2006
From: Cape Spencer, NB, CANADA
Status: offline 		Yup, I do think so!

I was surprised (to put it mildly) myself the first time I ran the doppler numbers. I've run them again and again, from several sound recordings. The lowest RPM I've seen on a speed pass (with diving entry, level for about 100 yds coming to the trap) was about 17100. For confirmation, I checked what it's doing on the back stretch (after climbing a hundred or 2 feet, and turning 180 degrees) and back there it's sitting in the high 15K's to low 16K's.

On the ground, it's taching right about 13K, give or take 300 for the weather. On take-off, the revs reach that static rpm sound immediately, and as the plane climbs out, so do the RPM's. About 14.5K at top of initial climb-out. First level stretch, and it's like I hit a turbo button, and it begins to unload and genuinely seems to "come on pipe". Once "on the pipe", nothing short of several hundred feet of vertical pull, or throttling back, will haul it down off the pipe. Further unloading (to almost stupid degrees) happen once I begin the dive into a speed pass.

And what a wonderful warbling scream it makes on a speed pass.

Other planes I fly have nothing like this engine's unloading. I really don't understand, but this engine loves to rev.

I'll letcha'all know when the bearings give up. Wonder if they'll survive this whole summer? Warranty ends this coming spring, so I assume they'll die early next summer

J

_____________________________

Revver Bro. #220

(in reply to airraptor)
       Post #: 35

RE: OS drops .32SX - 6/27/2008 4:28:13 PM   
Strykaas



Posts: 4107
Joined: 3/21/2003
From: Paris, FRANCE
Status: offline
quote:

ORIGINAL: airraptor
for 4, 5 or six. as long as it seal who cares how many it has.


Why not two head bolts, huh ?

_____________________________

ProBro #2077
http://image2-0.rcuniverse.com/e1/forum/upfiles/57402/Nl29490.jpg

(in reply to airraptor)
       Post #: 36

RE: OS drops .32SX - 6/27/2008 4:39:51 PM   
Jburry



Posts: 560
Joined: 7/12/2006
From: Cape Spencer, NB, CANADA
Status: offline 		Build the head thick and stiff enough, and 2 bolts could work. But she'll be a heavy engine!

Flange sealing (and a head is essentially a flange) is always a trade-off between number of bolts and flange stiffness. When the bolts are torqued, the head is actually very slightly warped like a wave washer. Gotta make those warp waves smaller than the compression achievable on the head gasket, so it can seal the loose areas still.

J

_____________________________

Revver Bro. #220

(in reply to Strykaas)
       Post #: 37

RE: OS drops .32SX - 6/27/2008 5:08:45 PM   
Strykaas



Posts: 4107
Joined: 3/21/2003
From: Paris, FRANCE
Status: offline
quote:

ORIGINAL: Jburry
Build the head thick and stiff enough, and 2 bolts could work. But she'll be a heavy engine!


Did OS make heads thicker and stiffer to move from 6 to 4 ?

I don't think so.

Would one single bolt be enough with a VERY thick and VERY stiff head ?

I don't think so.

_____________________________

ProBro #2077
http://image2-0.rcuniverse.com/e1/forum/upfiles/57402/Nl29490.jpg

(in reply to Jburry)
       Post #: 38

RE: OS drops .32SX - 6/27/2008 5:53:11 PM   
mmattockx


 

Posts: 2205
Joined: 4/28/2005
From: Calgary, AB, CANADA
Status: offline
quote:

ORIGINAL: Strykaas

Did OS make heads thicker and stiffer to move from 6 to 4 ?

I don't think so.

Would one single bolt be enough with a VERY thick and VERY stiff head ?

I don't think so.


Unless you measure the 6 bolt and 4 bolt heads, you don't know what OS did or did not do differently between them.

Yes, I could design a head that seals with one bolt. It would be heavy and ugly, but it can be done. Not very efficient for an aircraft engine, though.


Mark

_____________________________

Waco Brotherhood #4

(in reply to Strykaas)
       Post #: 39

RE: OS drops .32SX - 6/27/2008 6:01:17 PM   
evan-RCU