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 Today's Posts

Reply
 
Thread Tools Search this Thread Display Modes
  #21  
Old 09-09-2015, 01:00 PM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 5,297
Default

Quote:
Originally Posted by Raymo View Post
I agree but also think you may need to push the engine a little harder during break-in.

I believe you should keep it higher than 75% as long as cylinder and oil temps remain in the green zone. They should come down once the rings seat. At that point, oil consumption, CHT and oil temps should stabilize in the lower normal range.
Thanks. I intend to do this going forward and wished that I had for the last 10 hours.

Larry
Reply With Quote
  #22  
Old 09-09-2015, 01:07 PM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 5,297
Default

Quote:
Originally Posted by aerhed View Post
Who cleaned the oil sump? Intake tubes? Accessory case? Are the chunks hard? Cut one with a razor, is it old sealant or gasket?
I cleaned everything pretty well (including accy case and sump), but now that you mention it, I am not sure how thoroughly I cleaned the drain back tubes from the heads. It is possible the chunks were hiding there. I expect the oil has some detergent in it and may have loosened it. Anything visible was spotless.

The chunks are definitely carbon and not gasket material or sealant. They crack and crunch as expected.

Larry
Reply With Quote
  #23  
Old 09-09-2015, 10:31 PM
rhill rhill is offline
 
Join Date: Feb 2006
Location: Valley Forge, Pa
Posts: 636
Default

Quote:
Originally Posted by lr172 View Post
Thanks for your input here. I have been a bit afraid that glazing could be an issue here. I agree with putting more time on the engine to see what happens. How do I determine if I have a glazing issue? Is it just a matter of oil consumption not stabilizing? Does a compression test show glazing? Can I see it with a borescope?

The rod bushings were replaced during the overhaul and the rods were balanced as well.

Larry
Oil consumption is a biggie and of course Temperature,a cylinder leak down test,bore scope.I forgot to ask,How is your oil pressure cold&Hot? The rings like to move around and from time to time line up. The old numbered pistons weight could be all over the place and had to be matched by group.The new 14D numbers are made at Lycoming on a new machine that starts with a forging and comes out the other end a fully finished piston,even reaches out and wipes the drool off your face,its that slick. I have three sets,one of the old,I went through two cases to get 4 pistons that match within two grams.The other two sets were as sent and both are spot on. You don't know what you have till you weigh them. As before I'd run this some more but accept that their is enough going on that pulling all 4 jugs and the sump off for inspection is the right thing to do. IMHO
RHill

Last edited by rhill : 09-09-2015 at 10:37 PM.
Reply With Quote
  #24  
Old 09-10-2015, 01:48 PM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 5,297
Default

Quote:
Originally Posted by rhill View Post
Oil consumption is a biggie and of course Temperature,a cylinder leak down test,bore scope.I forgot to ask,How is your oil pressure cold&Hot? The rings like to move around and from time to time line up. The old numbered pistons weight could be all over the place and had to be matched by group.The new 14D numbers are made at Lycoming on a new machine that starts with a forging and comes out the other end a fully finished piston,even reaches out and wipes the drool off your face,its that slick. I have three sets,one of the old,I went through two cases to get 4 pistons that match within two grams.The other two sets were as sent and both are spot on. You don't know what you have till you weigh them. As before I'd run this some more but accept that their is enough going on that pulling all 4 jugs and the sump off for inspection is the right thing to do. IMHO
RHill
I went out and ran it hard yesterday for an hour and a half. 2600-2700 at 3000'. Oil Pressure was 70 PSI (typical) and temp never got over 195. CHT's were all 360, except #1, which is much richer and ran at 330. Oil pressure cold is 65. I won't know how much oil I am burning for another couple of hours.

My pistons came from Superior and had no numbers. Do you know if the the superiors more consistent in weight?

When I get to 40 hours, I will do a leak down test and borescope. If I have glazing problems, will I see it in the plugs? I am guessing that I would see oil on the plug or signs of oil fouling if the cylinder is glazed. Is that true? With the borescope, am I looking for excessive carbon desposits or coloring in the cross-hatch?
Larry

Last edited by lr172 : 09-10-2015 at 01:53 PM.
Reply With Quote
  #25  
Old 09-10-2015, 03:35 PM
rhill rhill is offline
 
Join Date: Feb 2006
Location: Valley Forge, Pa
Posts: 636
Default

Sounds like a plan. By then all this will sort itself out or you'll know for sure you got a problem.Cylinder leak down/compression test,Oil consumption,debris check the filter,Check the plug color,etc.The ECI/Superior pistons from Brazil are good,The weight issue may be a non event as you have 3 that are heavy and match? One a few grams lighter,if it were the other way around it would be more of an issue.The 2 plane prop balance might give you more data,stuff we covered in the other thread. Safe Flying!
RHill
Reply With Quote
  #26  
Old 09-12-2015, 06:18 PM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 5,297
Default

I had the cowl off today to install a new jet in my carb. I found that when I try to run rich that #3 :& #4 run lean and #1 & #2 filthy rich (will test performance with new jet tomorrow). While I was in there, I pulled the top plugs. #'s 1,3,4 look great. No oil and a nice grey cast to them with no fouling. #2 (the rich cylinder that I am struggling to lean) had wet oil on it and was pretty black (oil fouling). Obviously the rings haven't seated in this cylinder and explains the black oil. I looked in the hole with a flashlight and there is some glazing, but most of the cross-hatch is still clean (obviously I can only see a small portion - borescope arrives next week). If I can get this un-balanced mixture fixed and run it hard for 10 hours, what is the lkelihood that these rings will seat? Do I stand a chance? I guess the good news is that if I do have to hone and re-ring, it will only be one cylinder.

Larry
Reply With Quote
  #27  
Old 09-12-2015, 07:33 PM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
Posts: 5,516
Default

Quote:
Originally Posted by lr172 View Post
I had the cowl off today to install a new jet in my carb. I found that when I try to run rich that #3 :& #4 run lean and #1 & #2 filthy rich (will test performance with new jet tomorrow). While I was in there, I pulled the top plugs. #'s 1,3,4 look great. No oil and a nice grey cast to them with no fouling. #2 (the rich cylinder that I am struggling to lean) had wet oil on it and was pretty black (oil fouling). Obviously the rings haven't seated in this cylinder and explains the black oil. I looked in the hole with a flashlight and there is some glazing, but most of the cross-hatch is still clean (obviously I can only see a small portion - borescope arrives next week). If I can get this un-balanced mixture fixed and run it hard for 10 hours, what is the lkelihood that these rings will seat? Do I stand a chance? I guess the good news is that if I do have to hone and re-ring, it will only be one cylinder.

Larry
Typically, once glazed tear down is in order. In the old days a dash of BonAmi in the intake would provide just enough friction to seal the rings. Hard to do with load on an plane. Sorry, maybe RocketBob or Russ can provide a trick. It can't hurt to address the other issues first, then make a hard WOT run at 5-6000 for a couple of hours to finalize.
__________________
Bill

RV-7
Lord Kelvin:
“I often say that when you can measure what you are speaking about,
and express it in numbers, you know something about it; but when you
cannot measure it, when you cannot express it in numbers, your knowledge
is of a meager and unsatisfactory kind.”
Reply With Quote
  #28  
Old 09-12-2015, 10:12 PM
denbobp denbobp is offline
 
Join Date: Apr 2010
Location: California
Posts: 98
Default Chinks in oil

If all the chunks are the same size it's likely walnut chips typically used to clean engine cases on overhaul. Carbon doesn't coke till it gets to 400 degrees and you would have had high temps. 600 degrees for synthetics. Walnut hulls sometimes get stuck in oil passages and break free after a few runs. Remove your oil auction screen and clean that too. If the rest of your flakes are getting lessor so will your unknown chunks. I just got back from lycoming school yesterday and it was very informational.
Reply With Quote
  #29  
Old 09-14-2015, 08:59 AM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 5,297
Default

Quote:
Originally Posted by BillL View Post
Typically, once glazed tear down is in order. In the old days a dash of BonAmi in the intake would provide just enough friction to seal the rings. Hard to do with load on an plane. Sorry, maybe RocketBob or Russ can provide a trick. It can't hurt to address the other issues first, then make a hard WOT run at 5-6000 for a couple of hours to finalize.
I ran it hard for a couple of hours and no change. I ordered a ring kit today and will pull the cylinder, hone it and install the new rings. Better to do this now and not have to deal with another break-in cycle later. Heck, maybe I'll get lucky and find the odd piston pin on that cylinder and be able to replace it.

Larry
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 04:26 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.