How to dissemble head from cylinder

aungmyatoo Tue Apr 30, 2019 8:41 am

Anybody any idea how to dissemble head from cylinder without harming the cylinder?
I found out that head (aluminium) expansion ratio is higher than cylinder (iron) so heating doesn't work, even make it tighter.

Marleysky Tue Apr 30, 2019 9:34 am

aungmyatoo wrote:Anybody any idea how to dissemble head from cylinder without harming the cylinder?
I found out that head (aluminium) expansion ratio is higher than cylinder (iron) so heating doesn't work, even make it tighter.

Cox Instructions covered this in some instruction manuals. do not try to remove a glow head while hot! I guess the evaporation of the fuel would help cool the head enough to remove with out damage to the threads. I had success in separating a Testors 049 by leaving it in the freezer overnight. That might help shrink the cylinder enough to let the aluminum head break free. The most success I’ve had was to use a soldering iron and heat the piston and cylinder thru the exhaust slot (heating the bottom of the cylinder) while turning the head with a cox wrench just as the castor oils starts to turn into a liquid, before the aluminum expands and gets to tight.

How to dissemble head from cylinder Ec1faf10

Ken Cook Tue Apr 30, 2019 3:13 pm

A rubber strap wrench and I would still heat it.

Oldenginerod Tue Apr 30, 2019 5:19 pm

Heat will still help, although you need to then let it cool enough to balance the head and cylinder temperatures. The heat will expand the head, then as it cools it will contract and loosen easier. After warming you could give the head a quick blast of freeze spray. (Loctite Freeze & Release??). This will shrink it quickly, breaking the seal.

F4D Phantom II Tue Apr 30, 2019 5:50 pm

Hello
I would place it in the freezer until next day. I had a very stubborn Queen Bee head that didn`t want to come out, I placed the cilinder and head in a plastic bag in the freezer and next day it came out. Before that the wrench was starting to deform the slots on the head and the head was not budging. Give it a try before using more forceful methods.
Juan

NEW222 Tue Apr 30, 2019 6:11 pm

Definately heed teh above advice. I recently got an engien with a stuck head and did not want to come off. I did teh unthinkable and used pliers only after the Cox wrench damaged the mount on top of the head. Just to note, this was after heating it up using a butane torch. It still did not want to budge. I was upset, so I threw it in some nitro fuel. An hour later I was just windering, so I pulled it out, and it easily came apart..... I put the head in my drill and used a small file and sandpaper to bring it back to looking good. I did know better!

Dave P. Wed May 01, 2019 7:05 am

I heat the cylinder, avoiding heating the head, with a small torch until it's just barely too hot to hold and then hold an ice cube on the top of the head. Ten seconds later the head will loosen up easily. This works well with a stuck cylinder / crankcase too, only I heat the case and ice the cylinder.

getback Wed May 01, 2019 8:28 am

I have done the same but with hairdryer and run cold water over the part to be removed (( makes it alot easier )) Have used thick rubber hose for cyl. removable put on heat up use channel locks on hose rag and channel locks on case , Crude but effective !! Laughing

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How to dissemble head from cylinder

How to dissemble head from cylinder

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