VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.


Go Back   VAF Forums > Model Specific > RV-10
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #21  
Old 08-03-2021, 08:35 AM
jcarne's Avatar
jcarne jcarne is offline
 
Join Date: Jul 2016
Location: Worland, Wyoming
Posts: 1,930
Default

Quote:
Originally Posted by lr172 View Post
lead bromide becomes vapor around 800-1000 degrees and will typically not deposit above those temps. I have never seen my EGTs lower than 1200 in the pattern. Maybe my engine is different. At idle, the temps can get into that range and that is typically when lead deposits are made.

IMHO, leaning aggressively in the pattern is an accident waiting to happen. If I need power in the pattern, I likely need it NOW. Having to remember to go full rich increases the odds of becoming a statistic. There is a reason that pretty much EVERY certificated airframe manufacturer recommends full rich in the landing phase. I landed a couple of weeks ago with serious wind shear (10 kts surface/60 knots at 1500 AGL). My IAS was jumping between 75 - 100 MPH. I needed several LARGE throttle movements to stay safe. You just don't know when you will need aggressive throttle, but I promise that you will appreciate that it works when you need it when near the ground.

Larry
I get a couple cylinders that will do it. That low point is on final. This is also in a somewhat leaned state.

I think you also might of misinterpreted what I said. I do not lean aggressively in the pattern. I know Mike subscribes to LOP all the way to touch down; I do not, when I am a couple miles out I go rich of peak to my usual climb EGT. When I am in the pattern abeam the numbers I do add more mixture which allows me to jockey the throttle if needed. I was merely saying I do not go full rich as many do. If a guy wants to that's cool with me, I was just pointing out why Mike made that recommendation.

Lastly, "going full rich on final" is also a blanket statement that can be dangerous at a high density altitude airport on some engines.
Attached Thumbnails
Click image for larger version

Name:	Capture2.JPG
Views:	46
Size:	21.4 KB
ID:	14289  
__________________
Jereme Carne
PPL
RV-7A Flying as of 03/2021
Exempt but gladly paying!

Last edited by jcarne : 08-03-2021 at 08:43 AM.
Reply With Quote
  #22  
Old 08-03-2021, 08:49 AM
DanH's Avatar
DanH DanH is offline
 
Join Date: Oct 2005
Location: 08A
Posts: 10,294
Default

Quote:
Originally Posted by Strikhedonia View Post
My understanding is that by blocking off some of 3/4 it will push more air over 1/2/5/6 and provide some help cooling them. Is that incorrect?
Perhaps you could expand on how the blocking is installed.
__________________
Dan Horton
RV-8 SS
Barrett IO-390
Reply With Quote
  #23  
Old 08-03-2021, 08:53 AM
Strikhedonia Strikhedonia is offline
 
Join Date: Jan 2020
Location: Steamboat Springs, CO
Posts: 55
Default

Quote:
Originally Posted by DanH View Post
Perhaps you could expand on how the blocking is installed.
Vic did not go into detail on how to install it. My plan is to install aluminum tape to see if I can get the results I would like and if I can then I'll work on formulating a plan for installing the blocking.
__________________
www.strikhedonia.com
Chris French
RV10 flying
EAA #: 561223
Reply With Quote
  #24  
Old 08-03-2021, 11:07 AM
ReidVaitor ReidVaitor is offline
 
Join Date: Jun 2006
Location: SoCal
Posts: 192
Default Blocking 3-4

You want 2 to be cooler cut the deflector down in front of it, that will cool #2
You want to cool 5 and 6 by diverting air over the cooler 3-4? yes that will work.
I have a mentor that was into CART racing, knows his engines and cooling them, he (and I) have a 3/4 maybe, probably more deflector in front of 3-4 to move the air over them. I tried the aluminum tape and it didnít work, the deflectors when angled and sized correctly do the job. My #6 went down 15-20f (depends on time of year) my coolest 4 went up about the same. Now within 15f from coolest to hottest. HOWEVER this is based on the fact that my injectors are tuned for aggressive LOP. I hope Mike mentioned that injectors should be tuned before trying to lean successfully? my guess is if not the one closest to peak is running the hottest and the coolest probably the most lean.
When you get it figured out for your plane, let us know what you did to do so.
Reply With Quote
  #25  
Old 08-03-2021, 01:21 PM
DanH's Avatar
DanH DanH is offline
 
Join Date: Oct 2005
Location: 08A
Posts: 10,294
Default

Quote:
Originally Posted by Strikhedonia View Post
Vic did not go into detail on how to install it. My plan is to install aluminum tape to see if I can get the results I would like and if I can then I'll work on formulating a plan for installing the blocking.
See the sketch below. Tape or baffle rubber applied as in the topmost example should raise cylinder temperature, but it is unlikely to increase pressure, i.e. flow at the other cylinders.

Wraps up the sides per the middle example probably won't increase cylinder temperature, but will increase upper plenum pressure. The reason is an effective inlet restriction at the top of the wrap.

Small bent aluminum pieces can be added to the exit so as to decrease the exit area. If under the head, they may cause the CHT probe to read lower, although the actual overall temperature may not change much. They should increase upper plenum pressure.

I realize you believe your baffling is pretty good, but there are typically many large and small details which can lower CHT. For example, here we're talking about restricting flow to a pair of cylinders to raise flow at the other four, yet you probably have two or three blast tubes wasting pressure.
-
Attached Thumbnails
Click image for larger version

Name:	Capture.JPG
Views:	127
Size:	51.8 KB
ID:	14296  
__________________
Dan Horton
RV-8 SS
Barrett IO-390

Last edited by DanH : 08-04-2021 at 05:37 AM.
Reply With Quote
  #26  
Old 08-03-2021, 04:30 PM
Strikhedonia Strikhedonia is offline
 
Join Date: Jan 2020
Location: Steamboat Springs, CO
Posts: 55
Default

Quote:
Originally Posted by DanH View Post
See the sketch below. Tape or baffle rubber applied as in the topmost example should raise cylinder temperature, but it is unlikely to increase pressure, i.e. flow at the other cylinders.

Wraps up the sides per the middle example probably won't increase cylinder temperature, but will increase upper plenum pressure. The reason is effect inlet restriction at the top of the wrap.

Small bent aluminum pieces can be added to the exit so as to decrease the exit area. If under the head, they may cause the CHT probe to read lower, although the actual overall temperature may not change much. They should increase upper plenum pressure.

I realize you believe your baffling is pretty good, but there are typically many large and small details which can lower CHT. For example, here we're talking about restricting flow to a pair of cylinders to raise flow at the other four, yet you probably have two or three blast tubes wasting pressure.
-
Thanks, Dan. And you are right I do have two blast tubes for my PMags. Working to make the sealing as tight as possible but I'm definitely fighting against the necessary holes.
__________________
www.strikhedonia.com
Chris French
RV10 flying
EAA #: 561223
Reply With Quote
  #27  
Old 08-04-2021, 05:28 AM
Tooch Tooch is offline
 
Join Date: Nov 2011
Location: Amelia, Va
Posts: 314
Default Lean

I have been leaning all the way to landing for years even though I was not taught that way. I have never had a fouled plug. I don't know what the big deal is about go arounds. Just 3 levers up instead of 2. Practice it and it becomes second nature.
Reply With Quote
  #28  
Old 08-04-2021, 04:02 PM
GlennBfromOz GlennBfromOz is offline
 
Join Date: Jul 2017
Location: Sydney, Australia
Posts: 8
Default

Quote:
Originally Posted by Tooch View Post
I have been leaning all the way to landing for years even though I was not taught that way. I have never had a fouled plug. I don't know what the big deal is about go arounds. Just 3 levers up instead of 2. Practice it and it becomes second nature.
As a counterpoint, Iíve been richening in the circuit for years, and never had a fouled plug either

Some go-arounds happen at very short notice. When a new RV pilot bounces a wheeler, the fix is to get out of there before the bounces diverge. There isnít enough time, or enough hands, to be reaching for the prop and mixture before going to full throttle.

The same applies if a windshear or crosswind get out of limits. The pilot needs instant throttle response, and it may not be there if the mixture is still set for cruise.

I didnít intend to digress into piloting technique in this thread, and I hope Iím not insulting anyoneís intelligence. But claims such as ďhard on the engineĒ can lead into practices that create safety issues.

To be clear: Iím an advocate of LOP ops, and Iíll lean the engine aggressively when I can. But IMHO the approach phase isnít the time for it.
Reply With Quote
  #29  
Old 08-04-2021, 08:06 PM
Bill Boyd's Avatar
Bill Boyd Bill Boyd is offline
 
Join Date: Sep 2006
Location: Landing field "12VA"
Posts: 1,688
Default An observation:

If you have a quadrant, as Tooch probably does, it's an easy sweep of the open hand to go balls-to-the-wall on all three levers on a go-around. For vernier push-pull knobs, not so much. This may affect what pilots are comfortable with when it comes to the mixture setting on final.

I have a quadrant, but I run full forward prop and full rich mixture in the landing pattern, so it's only the throttle in play for a go-around, but if I didn't, it's not hard to shove it all forward at one time.

Honestly my biggest control manipulation worry in a go-around would be the caveat against opening the throttle too quickly on a counter-weighted engine like the IO-540 C4B5. That's supposed to be bad juju.
__________________
Bill Boyd

Hop-Along Aerodrome (12VA)
RV-6A - N30YD - Built '98 / sold '20
RV-10 - N130YD - 50 hours +
65 years running stock DNA
Reply With Quote
  #30  
Old 08-05-2021, 05:00 AM
Tooch Tooch is offline
 
Join Date: Nov 2011
Location: Amelia, Va
Posts: 314
Default

[quote=Bill Boyd;1545501]If you have a quadrant, as Tooch probably does, it's an easy sweep of the open hand to go balls-to-the-wall on all three levers on a go-around. For vernier push-pull knobs, not so much. This may affect what pilots are comfortable with when it comes to the mixture setting on final.


Bill is right. I have a quadrant in my 10 but my 7 did not but only had 2 push knobs, no constant speed prop, so it was never a problem for me. It may be different with the 3 push knobs.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 12:21 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.