Cox Engines Forum
You are not logged in! Please login or register.

Logged in members see NO ADVERTISEMENTS!


Deburring inside of cylinder Cox_ba12




Deburring inside of cylinder Pixel

Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Latest topics
» Inspect your Cox black 5x3 propellers
by roddie Today at 5:50 am

» **VOTE-ON-THE-NEXT-COX-ENGINE-OF-THE-MONTH** (March 2024)
by Admin Today at 2:43 am

» Cox .09 direction of rotation
by Greenman38633 Yesterday at 10:00 pm

» Fun this weekend
by roddie Yesterday at 9:52 pm

» Testors Silver Wind...........
by rsv1cox Yesterday at 6:10 pm

» First Swap Meet of the Year (for me).
by Ken Cook Yesterday at 4:09 pm

» dozens of old .049 TeeDee's, Medallions and a few others
by balogh Yesterday at 3:28 pm

» TD 09 Ducted Fan
by OVERLORD Yesterday at 11:18 am

» I would like to know how to date these Fox engines
by sosam117 Yesterday at 7:28 am

» *Cox Engine of The Month* Submit your pictures! -March 2024-
by sosam117 Yesterday at 7:20 am

» Three (now two) Cox .020 silencers for sale.
by 1/2A Nut Sat Mar 02, 2024 9:15 pm

» Three (Only one left) Cox .010 Carburetors with wrench
by 1/2A Nut Sat Mar 02, 2024 8:19 pm

Cox Engine of The Month
February-2024
1/2A Nut's

"RC Speed Boat Power Drive TD .020"

More info on this engine!




PAST WINNERS
CEF Traveling Engine

Win This Engine!
Gallery


Deburring inside of cylinder Empty
Live on Patrol


Deburring inside of cylinder

Go down

Help! Deburring inside of cylinder

Post  braggs Wed Jan 24, 2018 4:00 pm

Hello!

I have a .020 PeeWee that I'm restoring. The inside of the cylinder has burrs near the exhaust ports, caused by attempting to remove the cylinder with the Cox tool. This has caused the piston to bind as soon as it hits the bottom of the exhaust ports.  

Is there a way to deburr this without losing compression? Or is the cylinder done for?

Thanks for the help! For an old/niche engine, this forum is very active.
braggs
braggs
New Member
New Member

Posts : 3
Join date : 2018-01-11
Age : 27
Location : Prescott Valley, AZ

Back to top Go down

Help! Re: Deburring inside of cylinder

Post  Jason_WI Wed Jan 24, 2018 4:41 pm

The metal the cylinders are made from is very soft. An xacto with a sharp #11 blade can remove the burrs. I use a boom microscope with light source to see the high spot then scrape it down with the blade through the exhaust port. I’ll test fit with the piston. Any resistance means a high spot yet. I’ll then look for the high spot again under the scope and scrape that area only taking enough to remove that spot.

I have done .010 cylinders this way too.
Jason_WI
Jason_WI
Top Poster
Top Poster

2022 Supporter

Posts : 3123
Join date : 2011-10-09
Age : 48
Location : Neenah, WI

Back to top Go down

Help! Re: Deburring inside of cylinder

Post  Ken Cook Wed Jan 24, 2018 4:50 pm

I do this with .049 cylinders with a 80% success rate. Source a piece of tubing that fits fairly snug into the inside of the piston. If it's too loose, wrap tape around the tubing and force it into the underside of the piston. Take the piston and tubing and insert it upside down in the cylinder. Use Mothers Polishing compound or similar and pull the piston up to the point it begins to bind. Place a Q-tip full of Mothers into the the exhaust port and twirl. Don't be aggressive as it will jam the piston in the cylinder. Twirl the tubing while moving it slightly up and down. Eventually the burr will subside and allow the piston to come up higher in the bore. If the burr is very large, initially removing it can be done with a X-acto carefully using a jewelers loop to see it. Wash with hot soapy water to remove all traces of compound. I have used other forms of polishes and grits to speed this up if needed. Currently, if I have a problematic cylinder that won't tolerate finer compounds to fix, I use rottenstone mixed with oil and make it into a paste. Brasso works but is less aggressive . Powdered cleanser like Ajax works but you have to be very careful not to get carried away.
Ken Cook
Ken Cook
Top Poster
Top Poster

Posts : 5399
Join date : 2012-03-27
Location : pennsylvania

Back to top Go down

Help! Re: Deburring inside of cylinder

Post  rsv1cox Tue Mar 06, 2018 3:41 pm

So, I had three .049 cylinders, 1 thin wall with two bypass flutes, 1 thick wall with two flutes and one grooved with just a single flute that would not allow the piston past the mid to top point of the exhaust port.  Not seeing any indication of burr damage I tried well used 400 grit wet/dry paper lightly rolled and inserted through the bottom of the cylinder with a circular motion.  Finally, I got to a point where with some difficulty I could get the piston through the full length of the bore.  

Taking the worst of the three  I then used JB bore paste in the exhaust ports as Ken advised and chucked it up in a drill running it at a slow speed CW & CCW to good results.  Washed all components in hot soapy water, oiled and reassembled.  Added a new spacer/gasket and glow head and surprise = compression.  Won't be a barn-burner but it saved three cylinders from the scrap heap.  Eager to run it and check the RPM's.  

Deburring inside of cylinder Cox_bu12

Deburring inside of cylinder Cox_bu11

Deburring inside of cylinder Cox_bu10
rsv1cox
rsv1cox
Top Poster
Top Poster

2022 Supporter

2023 Supporter

2024 Supporter

Posts : 10354
Join date : 2014-08-18
Location : West Virginia

Back to top Go down

Help! Re: Deburring inside of cylinder

Post  Cox International Wed Mar 07, 2018 9:04 am

To note would be that the burr generally occurs when the Cox wrench is shoved though the exhaust ports instead of sliding it along the exhaust ports, as intended to be done with the wrench.
Cox International
Cox International
Top Poster
Top Poster

Official Cox Dealer
Posts : 3280
Join date : 2011-08-08
Age : 65
Location : Williams Lake, BC, Canada

http://www.coxengines.com

Back to top Go down

Help! Re: Deburring inside of cylinder

Post  Sponsored content


Sponsored content


Back to top Go down

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum