VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics


Go Back   VAF Forums > RV Firewall Forward Section > Traditional Aircraft Engines
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 01-11-2018, 06:26 PM
snopercod's Avatar
snopercod snopercod is offline
 
Join Date: Aug 2016
Location: Asheville, NC
Posts: 1,203
Default High Silicon in Oil Analysis Solved (I think)

Ever since my first flight in 2014, my oil analysis has come back "high silicon". The standard response has been "Your air filter sucks". It's a K&N, which is known to let more "stuff" through than some others, but I just didn't believe the filter was at fault because I don't fly off of dirt strips or in sand storms. So I ran an experiment. I had originally vented my crankcase with silicon rubber coolant hoses which ran to an oil separator, the drain of which was plumbed back to the crankcase with more silicon rubber hose. At the last annual back in August, I re-plumbed the system so the separator drain went to a little catch bottle rather than back into the crankcase. Wonder of wonders, the latest silicon reading went down from the 30-35 range to 14 this time. I'm calling "problem solved".
__________________
(2018 dues paid)
Reply With Quote
  #2  
Old 01-11-2018, 06:54 PM
pilotkms pilotkms is offline
 
Join Date: Mar 2007
Location: WARNER ROBINS, GA
Posts: 187
Default My experience

I also have an air oil separator that returns the oil to the crankcase. I just received my first (56 hours total time) oil analysis report and my silicon reading is 10. I used the silicon hoses provided by Antisplat. Maybe my hoses different than yours? Mine are the blue ones.
__________________
Keith
RV 7A. RV #9700
Built in SoCal KCCB
N325KS
Phase 1 Completed Nov 2017
120 Hours in Year 1 & 3x cross the USA
Reply With Quote
  #3  
Old 01-11-2018, 06:59 PM
snopercod's Avatar
snopercod snopercod is offline
 
Join Date: Aug 2016
Location: Asheville, NC
Posts: 1,203
Default

Go ahead. Make a liar out of me My hoses are green on the outside and red on the inside. They are coolant hoses for 18 wheel trucks. Maybe the anti-splat hoses are lined?
__________________
(2018 dues paid)
Reply With Quote
  #4  
Old 01-11-2018, 07:16 PM
pilotkms pilotkms is offline
 
Join Date: Mar 2007
Location: WARNER ROBINS, GA
Posts: 187
Default Sorry

Didnít mean to. 🙁 Iíll check the inside color tomorrow. And I also have a K&N filter. Mine is Horizontal induction.
__________________
Keith
RV 7A. RV #9700
Built in SoCal KCCB
N325KS
Phase 1 Completed Nov 2017
120 Hours in Year 1 & 3x cross the USA
Reply With Quote
  #5  
Old 01-12-2018, 08:53 AM
HFS HFS is offline
 
Join Date: Aug 2009
Location: Lemoore, CA
Posts: 225
Default K & N Filter

I use a K & N conical filter on my Rocket. I don't even bother "treating" it with their magic oil anymore - I looked up my last 10 oil sample analysis' and had an average of 6 ppm for silicon.

David
Reply With Quote
  #6  
Old 01-12-2018, 12:31 PM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 2,809
Default

Quote:
Originally Posted by snopercod View Post
Ever since my first flight in 2014, my oil analysis has come back "high silicon". The standard response has been "Your air filter sucks". It's a K&N, which is known to let more "stuff" through than some others, but I just didn't believe the filter was at fault because I don't fly off of dirt strips or in sand storms. So I ran an experiment. I had originally vented my crankcase with silicon rubber coolant hoses which ran to an oil separator, the drain of which was plumbed back to the crankcase with more silicon rubber hose. At the last annual back in August, I re-plumbed the system so the separator drain went to a little catch bottle rather than back into the crankcase. Wonder of wonders, the latest silicon reading went down from the 30-35 range to 14 this time. I'm calling "problem solved".
I don't believe that a high silicone content in your oil is a "problem" per se. It is reported as it helps to identify other "problems" such as poor air filtration.
__________________
N64LR
RV-6A / IO-320, Flying as of 8/2015
RV-10 in progress
Reply With Quote
  #7  
Old 01-12-2018, 02:27 PM
88Vans4 88Vans4 is offline
 
Join Date: Jan 2017
Location: East Hampton, CT
Posts: 10
Default

Do you have an oil filter? If you do and you happen to use Dow DC-4 Silicone lube on the filter gasket, that can raise the si level in the analysis.
It does in my reports if I get "sloppy" with the lube.
Mel B.
Reply With Quote
  #8  
Old 01-12-2018, 02:43 PM
snopercod's Avatar
snopercod snopercod is offline
 
Join Date: Aug 2016
Location: Asheville, NC
Posts: 1,203
Default

Quote:
Originally Posted by 88Vans4 View Post
Do you have an oil filter? If you do and you happen to use Dow DC-4 Silicone lube on the filter gasket...
Yes on the oil filter and I did always use DC-4 on the gasket. This last oil change, though, I installed a Tempest EZ-spin so in 25 hrs. we'll see if that makes a difference. I also have the RTV rocker cover gaskets.
__________________
(2018 dues paid)
Reply With Quote
  #9  
Old 01-12-2018, 02:51 PM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
Posts: 4,303
Default

Quote:
Originally Posted by snopercod View Post
Go ahead. Make a liar out of me My hoses are green on the outside and red on the inside. They are coolant hoses for 18 wheel trucks. Maybe the anti-splat hoses are lined?
Since you have all under control now, you can always put the hoses back on to show the silicon goes back up. It's bad when silicone gaskets, hoses, sealants etc push up the numbers, as it is the best indicator of air filter effectiveness, and thus barrel wear. Particle size and count measurements also can help augment the oil materials measurements for engine health understanding.
__________________
Bill

RV-7
Op Lims in hand 12-7-17
1st Flight 1-27-18
33/40 hrs
Aerobatics DONE!!
2017 Dues Paid
Reply With Quote
  #10  
Old 05-09-2018, 05:12 AM
snopercod's Avatar
snopercod snopercod is offline
 
Join Date: Aug 2016
Location: Asheville, NC
Posts: 1,203
Default Normal Silicon

I got my second oil analysis back after switching to a catch bottle rather than draining the oil separator back to the crankcase. Silicon was still normal for twice in a row. This reading was 17, up from 14 last time and in the twenties previously and forties originally. So the long term trend has been down. Hmmmm...
__________________
(2018 dues paid)
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 05:50 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.