Home > VansAirForceForums

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

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

Old 04-27-2022, 03:59 PM
TCONROY's Avatar
Join Date: Jul 2009
Location: Wilsonville, OR
Posts: 456
Default Piston head borescope question

Been flying for 7 years and have about 350hrs on the engine, which was a brand new Lycoming YIO-360-M1B purchased through Van's. I've done the condition inspection each year, following a very detailed and thorough checklist.
I purchased a USB camera and for the first time was able to snap some pics of my piston heads.

I don't really know what I'm looking at here, so looking for some advice and comments on whether the discoloration and build-up is normal. Thanks!




#4 Pic 1

#4 Pic 2

Trevor Conroy ATP, CFII, MEI
Airline Pilot
First Flight - April 12, 2015
Reply With Quote
Old 04-27-2022, 04:11 PM
Taltruda Taltruda is offline
Join Date: Oct 2017
Location: Las Vegas, NV
Posts: 1,188

I don’t lose sleep over how ugly the piston tops get.. the carbon is like the ceramic coating that people spend a lot of money on.. and you got it for free! What you want to do is see the valves.. does your borescope have a button to bend the head 180?
Las Vegas
RV-4 flying…
RV-8 empenage finished 10-2020

Wings Started.. 11-2020
Reply With Quote
Old 04-27-2022, 06:47 PM
Nick Leonard Nick Leonard is offline
Join Date: Jan 2005
Location: Sacramento, CA
Posts: 36
Default Lead Deposits

If I'm not mistaken what you are seeing is lead deposits which are gold to silver in color on most bore scopes. Most scopes don't have very good color rendition which has to be taken into account when looking in the cylinder. My understanding is that lead deposits are not an issue.

Regardless, for some good information on how to know when a valve is going bad, search for Anatomy of a Valve Failure on the site. I have a full sized print of the chart in a frame in my hangar for reference. Feel free to call if I can be of any help.
Nick Leonard (#40015) Finally Finished & Flying
C (916) 425-1064

Last edited by Nick Leonard : 04-27-2022 at 06:53 PM. Reason: more info
Reply With Quote
Old 04-27-2022, 08:01 PM
lipper03 lipper03 is offline
Join Date: Sep 2021
Location: Fulshear, TX
Posts: 80

Exhaust valve and cyl walls are the sports to look at also, but these look like normal cyl heads, carbon build up etc.. You want to see cross hatching in the cyl walls with even wear, and symmetrical “bulls eye” patterns on exhaust valves. AOPA and Mike Busch have some great articles and books on the subject.

Build Started 12/31/21-
Section 6 complete 1/30/22
Section 7 complete 3/27/22
*Emp Ordered 9/27/21- Assigned to crate June 2022
*QB Fuselage Ordered 11/3/21- Est 1Q23
*QB Wings Ordered 2/18/22- Est 2Q23
*YIO-390-EXP119 Engine Ordered 5/14/22- Est 2Q24

PA-28-236 N419SB

VAF donation 2021/22

CAF Member
EAA Member
AOPA Member
Reply With Quote
Old 04-27-2022, 09:03 PM
jneves's Avatar
jneves jneves is offline
Join Date: Aug 2021
Location: Livermore, CA
Posts: 189

Search Youtube for Mike B's webinar on valves and another on cylinders. LOTS of great info, as long as you can stand the slow pace in his talks. From your photos, all looks good, but as other have said the real area to look at are the valves. That plus a look at the cylinder walls.

N455DM - RV-6A - Bought Flying - 2021
Tip Up Canopy
FP 66" Catta 3 blade Carbon
IFR - 2 Garmin G5s - 430W - GFC500
JPI EMS-350 to monitor the temps
N89WD - Flight Design CTSW - Sold 2021
Donation Happily Made!
Reply With Quote
Old 04-27-2022, 09:38 PM
TCONROY's Avatar
Join Date: Jul 2009
Location: Wilsonville, OR
Posts: 456

Thanks all! Helps me rest a little easier. I will look into Mike's webinar regarding anatomy of a valve. I've seen some of his talks and he is truly a genius and very helpful to our community.
Trevor Conroy ATP, CFII, MEI
Airline Pilot
First Flight - April 12, 2015
Reply With Quote
Old 04-28-2022, 08:25 AM
WingnutWick's Avatar
WingnutWick WingnutWick is offline
Join Date: Jun 2013
Location: Fresno, CA (KFCH)
Posts: 308

I too just got a borescope and was at first surprised to see that build up as it looked just like yours. Thankfully the exhaust valves look good! Pretty sure this is normal. I invested in an articulating scope which is great!
F-18E/F, Mk.58, CF-5
Own: RV-8 & RV-10
Reply With Quote
Old 04-28-2022, 09:47 AM
BruceW BruceW is offline
Join Date: Aug 2005
Location: Elk Grove, CA
Posts: 255

Hope you get some burnt pizza!
Bruce W
RV-7 QB (500+ hours)
RV-14 in waiting
Elk Grove, CA
Reply With Quote

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 06:50 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.