Go Back  RCU Forums > RC Airplanes > RC Jets
Reload this Page >

Help with turbine sizing (bifurcated pipe)

RC Jets Discuss RC jets in this forum plus rc turbines and ducted fan power systems

Help with turbine sizing (bifurcated pipe)

Reply

Old 02-12-2018, 04:01 PM
  #1  
bushong572
Thread Starter
My Feedback: (59)
 
Join Date: Jun 2003
Location: Midland, TX
Posts: 235
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Help with turbine sizing (bifurcated pipe)

I have a 1/6 F-16 (31 lbs unfueled) that has a Jet Central 140n in it. I am very happy with the way the 140 pushes it around. I am building a F-18 (just a tad smaller and maybe 1 lb less) that I planned on putting a Kingtech 140n in . I would like similar performance to the F-16. My questions: Do you lose some thrust with a bifurcated pipe? Should I go to a 160n-180n on the F-18 because of the pipe?

Thanks
bushong572 is online now  
Reply With Quote
Old 02-12-2018, 05:00 PM
  #2  
ravill
My Feedback: (11)
 
ravill's Avatar
 
Join Date: Jan 2003
Location: Redwood City
Posts: 4,677
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I've had quite a few F-18's. Charlies, Foxtrots and Echo's.

Which F-18 do you have? And who makes it?

The "smaller" C's will fly around ok with a 120N engine and better with a 140N engine. But if you have the bigger "supas" or want better vertical performance (like real 18's! LOL) 160+ all the way.

And yes, you loose power through a bifurcated pipe. Last time I read about power losses, they were in the 5-10%, but don't quote me on that please!

Good luck!
ravill is online now  
Reply With Quote
Old 02-12-2018, 06:37 PM
  #3  
bushong572
Thread Starter
My Feedback: (59)
 
Join Date: Jun 2003
Location: Midland, TX
Posts: 235
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Thanks for the reply.
It's a Fei Bao 1/8 F-18F (super).

It sounds like I need to go with a 160.
bushong572 is online now  
Reply With Quote
Old 02-14-2018, 06:07 PM
  #4  
mongo
My Feedback: (14)
 
mongo's Avatar
 
Join Date: Dec 2001
Location: Midland, TX
Posts: 2,546
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

there is a K-160 or 180 in the classifieds here. guy in grandbury TX has it.

make that a K-210, the k-170 is in GA.

Last edited by mongo; 02-14-2018 at 06:11 PM. Reason: correction
mongo is online now  
Reply With Quote
Old 02-14-2018, 06:13 PM
  #5  
bushong572
Thread Starter
My Feedback: (59)
 
Join Date: Jun 2003
Location: Midland, TX
Posts: 235
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I saw them. A 210 is too big and the 170 is propane. I've been looking for a good deal on a kero start 160 for a while.

Thanks
bushong572 is online now  
Reply With Quote
Old 02-15-2018, 07:32 PM
  #6  
bidrseed2
My Feedback: (2)
 
Join Date: Apr 2004
Location: billingshurstsussex, UNITED KINGDOM
Posts: 504
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I thought the thrust loss was greater than that. Back in the day, I thought I’d read a 120N straight pipe Eurosport performed like a 160N Eurosport with a bifurcated pipe.
bidrseed2 is offline  
Reply With Quote

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


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service