enginehistory.org

[jsewell]

how do you compress the rings in a junk head and install it into the sleeve?

[cestieoulle]

You need a special tool (like an hinged collar with 2 handles) which compress rings, as for piston rings.
The collar width is designed for the number of rings (2 rings in Bristol Hercules for example)
You put the sleeve in the maximum upper position.
You set the rings in correct position and compress them with the tool.
As junk head rings are in the bottom of the head, you just have to slide the head in the sleeve, holding the tool handles.
When rings are inserted, you have enought room left to open you tool and disengage it.
Then you can complete the setting of the head.
Don't forget to oil !!
A scheme or pictures would have been clearer, but i've no documents available at the moment.
Hope this help
Christian

[jsewell]

so the gap between the top ring and the upper part of the junkhead has to be large enough to allow the ring to slide into the sleeve and out of the ring compression tool?

[cestieoulle]

As I've no junk head for measuring, all figures are from my memory !
For Bristol Hercules, the inside part in the sleeve is about 3.25 " high, rings are in the lower position which leave more than 2.5" free.
The ring compression tool is about 1" high.
So you have enough room to remove the tool when rings are inserted inside the sleeve - without letting them escape !
Christian

[cestieoulle]

This a link to a short video showing how things works:
http://www.youtube.com/watch?v=Liqqo8Cdb68
The junk head is in red and you can see how deep it goes inside the sleeve.
You can have a short view of head rings through the inlet port (above position).
Christian

[amarshall]

Gidday all, I have posted a short clip inside one of the cylinders of the Bristol Hercules that I am restoring. Look up Bristol Hercules Sleeve Valve on Youtube - it won't be hard to find.