VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #11  
Old 10-27-2017, 11:12 AM
RFSchaller RFSchaller is offline
 
Join Date: Oct 2010
Location: Phoenix, AZ
Posts: 2,114
Default

When I took the ROTAX course the instructor had a home made setup using the manifold pressure gage from a twin engine aircraft. It worked great, but the Carbmate seems to have a better resolution than what you can see on the analog gage. On the other hand maybe “close enough” is good enough.
Reply With Quote
  #12  
Old 10-27-2017, 03:26 PM
Phantom30's Avatar
Phantom30 Phantom30 is offline
 
Join Date: Jul 2009
Location: Coeur d'Alene, ID/Casa Grande, AZ
Posts: 566
Default

Quote:
Originally Posted by RFSchaller View Post
When I took the ROTAX course the instructor had a home made setup using the manifold pressure gage from a twin engine aircraft. It worked great, but the Carbmate seems to have a better resolution than what you can see on the analog gage. On the other hand maybe “close enough” is good enough.
Richard...what airfield are you based @ in Phoenix?
__________________
Ric Dickison
307 (CAB) Phantom
Search and Destroy (Can
Tho RVN)
Distinguished Flying Cross Society Member
CH-47 & UH-1H "Driver"
Rotax 9 Series Service IRMT

RV-12 Kit#729 "N312RD" is now a full functioning fun machine!! Thanks Van for fulfilling my dream😎
2017 Dues Paid
Reply With Quote
  #13  
Old 10-30-2017, 02:00 PM
RFSchaller RFSchaller is offline
 
Join Date: Oct 2010
Location: Phoenix, AZ
Posts: 2,114
Default

Glendale. Desert Hangar Owners Hangar #24.
Reply With Quote
  #14  
Old 10-30-2017, 03:28 PM
ben barron ben barron is offline
 
Join Date: Sep 2013
Location: Fall City, WA
Posts: 91
Default

I am seeing a 0 to 56 degree delta (right side higher).
I was told (at my 200 hour / annual) this was good and no balancing was necessary by the mechanic doing the work. Is this consistent with what you are finding?
__________________
B2RV12
Reply With Quote
  #15  
Old 10-30-2017, 03:46 PM
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 6,972
Default

Personally I don't consider EGT as a reliable indication of carb. synch/balance. If it was reliable I think Rotax would have put it in the maint. documentation.
__________________
Any opinions expressed in this message are my own and not necessarily those of my employer.

Scott McDaniels
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
Reply With Quote
  #16  
Old 10-30-2017, 05:27 PM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
Join Date: Nov 2014
Location: Hinckley, Ohio
Posts: 714
Default

I balanced my carbs with two vacuum gages. When I was satisfied that they were closely synched I then transferred the vacuum gages L>R to make sure they was no gage bias. I then looked at EGT's for idle and off-idle and they are very closely matched. I frequently monitor the EGT's and will re-balance if differential ever changes...
__________________
-
Jim Stricker
Hinckley, Ohio
PPL - 1970
80 hrs Flying Aeronca Chief 11AC
1130 hrs Flying 46 Piper J-3 Cub
RV-12 E-LSA #120058 AWC 7/12 Bought Flying 10/2015 with 48TT - Hobbs now 315
Reply With Quote
  #17  
Old 10-30-2017, 10:19 PM
RFSchaller RFSchaller is offline
 
Join Date: Oct 2010
Location: Phoenix, AZ
Posts: 2,114
Default

Above about 4000 RPM the intake manifolds will have the same pressure unless your throttle cables are completely out of whack, so I would not expect cruise RPM to be a good indicator of synchronization. The ROTAX instructor told us that is why you do the ignition check at 4000 RPM: to eliminate carb synch as a factor in rough running during the check. It makes sense considering the throttling profile of a butterfly valve. After about the first 50 degrees of rotation they have little restriction to airflow.
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 03:46 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.