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  #21  
Old 12-04-2019, 02:31 PM
partner14 partner14 is offline
 
Join Date: Feb 2008
Location: Pecan Plantation Granbury TX
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In response to: Throttling an engine with the butterfly in the servo results in higher pumping loss than if the engine is free to breath unrestricted. In your example above, why wouldn't you shove the throttle in and grab those two inches of MP, but simply lean back to your 9.5 GPH? All else equal, the engine should produce a bit more power (with less pumping loss), and your CHTs will come down too.

Like I said, at times while at wot the temps stay just fine, other times not so much. I continue to lean while watching the cht's, and try to find a spot where everyone is happy. If that doesn't work, pulling back the throttle a little works just fine.
Don
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  #22  
Old 12-04-2019, 02:50 PM
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DeeCee 57 DeeCee 57 is offline
 
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Location: LSZF
Posts: 421
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this thread should be titled "Great speeds in a Tailwind"... mother Nature helping hand and it ain't really RV related, is it?
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  #23  
Old 12-04-2019, 02:58 PM
BobTurner BobTurner is offline
 
Join Date: Dec 2011
Location: Livermore, CA
Posts: 6,797
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Quote:
Originally Posted by partner14 View Post
Like I said, at times while at wot the temps stay just fine, other times not so much. I continue to lean while watching the cht's, and try to find a spot where everyone is happy. If that doesn't work, pulling back the throttle a little works just fine.
Don
Like a few other posters, I?m scratching my head here, trying to explain how any combination of throttle or mixture could result in ?unhappy? CHTs, at 15K?. Do you have a fixed timing (mag or otherwise) ignition?
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  #24  
Old 12-04-2019, 03:09 PM
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RV7A Flyer RV7A Flyer is offline
 
Join Date: Jul 2013
Location: US
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Quote:
Originally Posted by partner14 View Post
As far as flying at half throttle.... My engine (IO540) has higher compression and cold air induction, so I pay really close attention to CHT's. Sometimes the temps are fine at WOT, but a higher percentage of the time they're not. You can see the numbers, they're almost perfect.... they wouldn't be if I was WOT.
Pics in post 1 don't work for me, so I'll ask...what do you mean by "fine", and "not [fine]", in degrees?
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  #25  
Old 12-04-2019, 03:52 PM
partner14 partner14 is offline
 
Join Date: Feb 2008
Location: Pecan Plantation Granbury TX
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Really didn't think about what could happen by posting what I thought was an interesting event due to the wind. So what we have so far is we don't know **** if even some of our instruments have mph. Then I actually used the wrong title, and because the wind was responsible, it wasn't even RV related.
Then even though I was well within the green arc, some think I need remedial training.
I have dual lightspeed electronic ignition. Was told, and later confirmed, that with an RV10 if you have cold air induction and higher compression you will have heat issues. So why can't anyone just believe what a person says about their plane without trying to school them.
I will delete this post. Sorry
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  #26  
Old 12-04-2019, 03:56 PM
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airguy airguy is offline
 
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Location: Garden City, Tx
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Quote:
Originally Posted by partner14 View Post
Really didn't think about what could happen by posting what I thought was an interesting event due to the wind. So what we have so far is we don't know **** if even some of our instruments have mph. Then I actually used the wrong title, and because the wind was responsible, it wasn't even RV related.
Then even though I was well within the green arc, some think I need remedial training.
I have dual lightspeed electronic ignition. Was told, and later confirmed, that with an RV10 if you have cold air induction and higher compression you will have heat issues. So why can't anyone just believe what a person says about their plane without trying to school them.
I will delete this post. Sorry
Welcome to the Internet.
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Built an off-plan RV9A with too much fuel and too much HP. Should drop dead any minute now.
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  #27  
Old 12-04-2019, 04:27 PM
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kevinsrv7.com kevinsrv7.com is offline
 
Join Date: Aug 2006
Posts: 145
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Quote:
Originally Posted by partner14 View Post
I was encouraged to post this on Van's Air Force's website, so here goes. After all the terrible weather last week, we needed a window of decent weather to return to Texas from SoCal. We had no idea of just how great the flight would be. Kind of wondering if anyone else has seen these kind of ground sppeds in their RV's. Flying with half throttle, 2,230rpm, climbing at 200fpm, at 15,480', and LOP, we saw . IAS = 154mph, TAS = 198mph, Ground Speed (GPS) = 266kts, or 306mph, wind speed = 110mph.
The second picture taken 72nm earlier shows 301mph, climbing 300fpm, and 8.7gph, which is almost 35mpg.
https://www.facebook.com/photo.php?fbid=3557500467608318&set=pcb.3557530554 271976&type=3&__tn__=HH-R&eid=ARChiHpFgvOyTT2DTMlmONLmpDoeN3HwBZa_ebCJrFHy 8PeMTFxBwMNSwxrWJ-6q6Z21bv0e_uVSabuQ[/IMG]
https://www.facebook.com/photo.php?fbid=3557507254274306&set=pcb.3557530554 271976&type=3&__tn__=HH-R&eid=ARAW_P0xD4pKnYu3G6N3XZBwJrN4ed_Fm7bXWLmLn0G2 U0x2nWjRUJHcOfSvgw4-6dTBN8xC4rw7aP9M[/IMG]

Don McDonald 0TX1
RV10 40636 1,100 hours and loving it.
Great write up Don thanks for sharing. Nice work There is no need to delete your post, I think the majority of us really enjoyed and learned from it.
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  #28  
Old 12-04-2019, 04:29 PM
romaja romaja is offline
 
Join Date: Jan 2016
Location: Portland Oregon Area
Posts: 81
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Quote:
Originally Posted by partner14 View Post
Really didn't think about what could happen by posting what I thought was an interesting event due to the wind. So what we have so far is we don't know **** if even some of our instruments have mph. Then I actually used the wrong title, and because the wind was responsible, it wasn't even RV related.
Then even though I was well within the green arc, some think I need remedial training.
I have dual lightspeed electronic ignition. Was told, and later confirmed, that with an RV10 if you have cold air induction and higher compression you will have heat issues. So why can't anyone just believe what a person says about their plane without trying to school them.
I will delete this post. Sorry
I found your post interesting. It is nice getting a strong tailwind especially if it is smooth. Airguy is right. Welcome to the Internet. An unfortunate byproduct of some forums.

Jim
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  #29  
Old 12-04-2019, 04:37 PM
Capt Capt is offline
 
Join Date: Feb 2017
Location: Australia
Posts: 615
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Quote:
Originally Posted by N941WR View Post
His TAS was well below his Vne, so no issues. Notice he listed both IAS and TAS.
I never said this guy was near VNE, you missed my point! It's the misconception that some think that being in the green arc all is good at high Alt! Often not so!
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  #30  
Old 12-04-2019, 05:16 PM
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Toobuilder Toobuilder is offline
 
Join Date: Jul 2009
Location: Mojave
Posts: 4,652
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Quote:
Originally Posted by partner14 View Post
... So why can't anyone just believe what a person says about their plane without trying to school them...
Probably because this forum spends a lot of time debating high CHT, running LOP, TAS/flutter, and ignition timing. These are hot button issues and you touched ALL of them in your first post. Welcome to the internet.

No offense intended, but many of us have been down this road and overcome the "problems" you are having with your bird. Most of us are here to help if you want it.
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