VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics


Go Back   VAF Forums > Main > RV General Discussion/News
Register FAQ Members List Calendar Today's Posts

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 09-06-2010, 01:06 PM
B25Flyer B25Flyer is offline
 
Join Date: Nov 2005
Posts: 358
Default Oil Consumption problem found....

The Rocket has been slowly increasing oil consumption for over a year. I could see that the problem was on the left side of the engine based on the soot on the left side of the belly. The compressions are all in the mid-70s so it either had to be an oil ring or valve guide.

I flew to TX last week and in 4 hours I added 3 qts so I decided that it would not wait until winter, so I pulled the cowl and pulled the plugs on the left side.

#4 was oily so I pulled the exhaust. 2 and 6 were nice and tan and 4 was coal black and sooty, so I pulled the cylinder.

As the Cylinder came off pieces of the oil ring feel out on the floor.... There is a gouge in the ring groove where the broken piece was located. The cylinder looks good!!! I think a hone job and new piston will solve the problem....

1100 hours and everything else looks good, and nice and clean inside.....

Tailwinds,
Doug Rozendaal
F-1 Rocket
Reply With Quote
  #2  
Old 09-06-2010, 01:49 PM
pierre smith's Avatar
pierre smith pierre smith is offline
 
Join Date: Jan 2005
Location: Louisville, Ga
Posts: 7,840
Default I'm curious....

...as to how and why an oil control ring can break while it's seated in the groove...hmmm.

Was the oil consumption good, early in the engine's life?

Best,
__________________
Pierre Smith
RV-10, 510 TT
RV6A (Sojourner) 180 HP, Catto 3 Bl (502Hrs), gone...and already missed
Air Tractor AT 502B PT 6-15 Sold
Air Tractor 402 PT-6-20 Sold
EAA Flight Advisor/CFI/Tech Counselor
Louisville, Ga

It's never skill or craftsmanship that completes airplanes, it's the will to do so,
Patrick Kenny, EAA 275132


Dues gladly paid!
Reply With Quote
  #3  
Old 09-06-2010, 02:09 PM
B25Flyer B25Flyer is offline
 
Join Date: Nov 2005
Posts: 358
Default

I bought it with 300 hrs and it has about 1100 now. It has always used some oil, but it has been on the increase for the last year.

My Mech. said that this is pretty common...

Doug Rozendaal
Reply With Quote
  #4  
Old 09-06-2010, 02:47 PM
Walt's Avatar
Walt Walt is offline
 
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 5,668
Default

Just an FYI, cylinders are usually replaced in opposing pairs (to keep the engine inertia forces balanced). If you do just one piston, you need to get one as close to the same weight as the one you are replacing as possible.
__________________
Walt Aronow, DFW, TX (52F)

EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 1700+ hrs, New Titan IO-370, Bendix Mags
Website: ExpAircraft.com, Email: walt@expaircraft.com, Cell: 972-746-5154
Reply With Quote
  #5  
Old 09-06-2010, 02:59 PM
B25Flyer B25Flyer is offline
 
Join Date: Nov 2005
Posts: 358
Default

The parts all came from Barrett and I am hoping they have a record of the piston weight and can match it....

Doug Rozendaal
Reply With Quote
  #6  
Old 09-06-2010, 05:41 PM
rocketbob's Avatar
rocketbob rocketbob is offline
 
Join Date: Jun 2006
Location: 8I3
Posts: 3,562
Default

Quote:
Originally Posted by pierre smith View Post
...as to how and why an oil control ring can break while it's seated in the groove...hmmm.

Was the oil consumption good, early in the engine's life?

Best,
If there is a pronounced wear step on the cylinder at the bottom and top of piston travel, that can/does cause the rings to flutter and eventually break. Broken rings aren't uncommon.
__________________

Please don't PM me! Email only!

Bob Japundza CFI A&PIA
N9187P PA-24-260B Comanche, flying
N678X F1 Rocket, under const.
N244BJ RV-6 "victim of SNF tornado" 1200+ hrs, rebuilding
N8155F C150 flying
N7925P PA-24-250 Comanche, restoring
Not a thing I own is stock.
Reply With Quote
Reply



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 01:10 AM.


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.