Glow Engines Discuss RC glow engines

What prop to use on a S.T. G90 ?

Reply
Old 03-16-2009, 03:47 AM
  #1
Bob Paris
Thread Starter
 
Join Date: Nov 2002
Location: Lahaina, HI
Posts: 1,832
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default What prop to use on a S.T. G90 ?

Hi Guys...
Any one familure with the ST G90 ? I have a G90 in a 66" span P-51B that weights out 9 lbs.-11 1/2 oz. I have been told that a 14 x 6 would be good...and I installed a 15 x 4 for the break in and first flights.

What do you think... ? I can use all the imput from experienced flyers of the G90.

Thanks, and Soft Landings Aways,
Bobby of Maui
Attached Thumbnails
Click image for larger version

Name:	Ca81331.jpg
Views:	14
Size:	88.2 KB
ID:	1158928   Click image for larger version

Name:	Om33102.jpg
Views:	17
Size:	50.8 KB
ID:	1158929  
Bob Paris is offline  
Reply With Quote
Old 03-16-2009, 05:20 AM
  #2
rcdude7
 
Join Date: Apr 2003
Location: Great Mills, MD
Posts: 2,223
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

Bob, I have used a 13X7 and 13X8 in the faster planes, the 14X6 you have might work. I would try something with more than 4" of pitch in your warbird, it will perform better.
rcdude7 is offline  
Reply With Quote
Old 03-16-2009, 07:47 AM
  #3
Sport_Pilot
 
Sport_Pilot's Avatar
 
Join Date: Jan 2002
Location: Acworth, GA
Posts: 16,889
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

I suspect a 13x7 or 13x8 would be best. But it will take a longer takeoff run. I would use the 14x6 then the 13x7 and last the 13x8, if only to get used to the lower thrust and higher speed.
Sport_Pilot is offline  
Reply With Quote
Old 03-16-2009, 08:49 AM
  #4
w8ye
Moderator
 
w8ye's Avatar
 
Join Date: Dec 2001
Location: Shelby, OH
Posts: 37,526
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

I would not try flying a warbird with a 4" pitch prop
w8ye is offline  
Reply With Quote
Old 03-16-2009, 10:06 AM
  #5
daveopam
Moderator
 
daveopam's Avatar
 
Join Date: Oct 2002
Location: ELK CITY, OK
Posts: 7,318
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

I have 5 ST90's. I use a 14x6 on 4 of them.APC and MA are about the same on this engine. The last one uses a 13x8APC. It's in a mustang.

David
daveopam is offline  
Reply With Quote
Old 03-16-2009, 10:55 AM
  #6
w8ye
Moderator
 
w8ye's Avatar
 
Join Date: Dec 2001
Location: Shelby, OH
Posts: 37,526
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

The 13 X 8 will give you better fast fly-by's more ground clearance etc
w8ye is offline  
Reply With Quote
Old 03-16-2009, 11:02 AM
  #7
jaka
 
Join Date: Dec 2001
Location: Upplands Vasby, SWEDEN
Posts: 7,638
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

Hi!
14X6 or 13X8 APC or RAM!
jaka is offline  
Reply With Quote
Old 03-16-2009, 02:00 PM
  #8
Bob Paris
Thread Starter
 
Join Date: Nov 2002
Location: Lahaina, HI
Posts: 1,832
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

Thanks Guys,
Great information, and I will use a 14 x 6.

I had considered the 15 x 4 because on the first flights I am not looking for speed...but for good thrust and power. This model is a modified cheap China made P-51D I kit bashed into a "B." Speed is not my first concern, but good pulling power, that is why I was considering the 15 x 4.

Thank you for all your comments...and Soft Landings Always,
Bobby of Maui
Bob Paris is offline  
Reply With Quote
Old 03-16-2009, 02:34 PM
  #9
XJet
 
Join Date: Mar 2003
Location: Tokoroa, , NEW ZEALAND
Posts: 3,848
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

A 14x6 will give you good vertical and quick acceleration on take-off but a 13x8 will give you a *slightly* higher top-speed.

It's also worth trying a MAS 13x6 Scimitar, these have worked *very* well for me on the G90.

Also, if you want a really nice prop-noise, the MAS K-series 14x6 or 13x8 will give you that at the sacrifice of some performance. Sounds great though :-)
XJet is offline  
Reply With Quote
Old 03-16-2009, 03:19 PM
  #10
Bob Paris
Thread Starter
 
Join Date: Nov 2002
Location: Lahaina, HI
Posts: 1,832
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

Hay XJet,
I have the Master Air Screw 13x6 and 14x6 wood props and I've been using them for a while now. I don't use plastic props any more and gave all mine away or traded them off. I witnessed a man losing several fingers with an APC prop and it scared the heck out of me. Wood props will break...plastic props amputate.

I'm not looking for speed...though I do believe the G90 will take this less then ten pound model for a good run. I like a solid climb with my new models...and why I was considering using a Zinger Pro 15 x 4 for the first flights. But it seems that no one liked my idea of using a 15 x 4 on a G90 in this model.

Thanks for the imput,
Bobby of Maui
Bob Paris is offline  
Reply With Quote
Old 03-16-2009, 03:28 PM
  #11
w8ye
Moderator
 
w8ye's Avatar
 
Join Date: Dec 2001
Location: Shelby, OH
Posts: 37,526
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

A wood prop will mangle your fingers very badly also. It happened to me 40 years ago with a wood prop.
w8ye is offline  
Reply With Quote
Old 03-16-2009, 03:55 PM
  #12
daveopam
Moderator
 
daveopam's Avatar
 
Join Date: Oct 2002
Location: ELK CITY, OK
Posts: 7,318
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

If you want instant throttle response for the first few flight then put a MA 13x6 on it.

David
daveopam is offline  
Reply With Quote
Old 03-16-2009, 05:13 PM
  #13
jjscott
 
jjscott's Avatar
 
Join Date: Jul 2007
Location: Elm Grove, WI
Posts: 479
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

Not exactly on topic but Omni Models (and Tower) have the G90 on sale right now for 99.98. Omni gives you a $10 discount for orders over $100 and waives the shipping charge. Add some fuel line or a motor mount & you're over the $100. The regular discount price for the motor is 129.95.

Jim
jjscott is offline  
Reply With Quote
Old 03-16-2009, 09:46 PM
  #14
j.duncker
Moderator
 
j.duncker's Avatar
 
Join Date: Jun 2004
Location: Sailing in the Eastern Caribbean
Posts: 3,749
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

I used a 12x8 on my ST 90s flying pattern and a 13x6 in slower flying models. This should be close to peak power in the air in level flight IMHO.

However when I moved to a club with a strict noise rule I used a 14x6 APC and it was OK on this as well.
j.duncker is offline  
Reply With Quote
Old 03-16-2009, 11:24 PM
  #15
Bob Paris
Thread Starter
 
Join Date: Nov 2002
Location: Lahaina, HI
Posts: 1,832
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: What prop to use on a S.T. G90 ?

Thanks Guys...
I'll try both the 13x6 and 14x6 and see what each prop gives me.
Soft Landings Always,
Bobby of Maui
Bob Paris is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 03:32 AM.