Cylinder block O'rings.

[Piki]

Hi all, anyone know what function have o'ring?
Number 283:
http://www.cmsnl.com/honda-cb400f-general-export-kph_model14637/partslist/E01-1.html#results

Best Regards.

[steven400/4]

they sit in the reset on the bore sleeves oil seals i think

[Bryanj]

around the cylinder sleeve on the bottom above the base gasket in a groove

[Piki]

thanks ......... but what is its function? At the site where they are placed does not seem very important.
I have raised the head engine(I am working about one oil leak) and the cylinder block has risen also(the cylinder block was attached to the cylinder head),I looked below the cylinder block and seen the o´rings are out of place. I can not put it into place(I do not want take off the cylinder block because the engine has only 1200 milles with new o´rings from the last restauration), and I thought of leaving them as they are.............. What can I do?
Thank you very much and sorry for me English.

[Bitsa (Ralph Wright - RIP)]

Piki.
As with all Honda cylinders I think its meant to stop oil going up between the cylinder liners and the aluminium barrel.There is a certain amount of crankcase pressure.
This is what I believe otherwise why would Honda fit them?
Hope this helped you.
Cheers
Bitsa

[Piki]

Thank you Bitsa, I understand you, but how can I fit the o´rings in its correct location without take off the cylinder block??? I can see a little from the o´ring out from its place, but I can not put it in the correct position because I do not have space to work and I do not want to take off the cylinder block..........

[Bitsa (Ralph Wright - RIP)]

Piki.
Without removing the barrels it is almost impossible to seat them correctly.When rebuilding the engine I used to smear them with grease and push them home once the block was on they do not shift.If you lift the cylinders to just before the pistons come out its tricky and time consuming but using a feeler gauge you may have success in pushing them back.If they have stretched it will be a bast**d.Why can you not lift the block?I have removed the block many a time with a 400/4 and refitted no problem.Wish you all the best.
Cheers
Bitsa

[Piki]

Hi Bitsa, I do not want to take off the block because the rings will change its position(they moves) and then them Will work in other position on the cylinder and this is not good. The engine has 55000 km and I have fit new rings( 53000km)

[Bryanj]

Doesn't matter as the rings rotate around the piston when running

[Piki]

Hello, really? I read in Forums and talk with the mechanic that it is not good, because the rings  has worked in a position and they are fit about to a determinate shape the cylinder bore if we change the position of the rings, the rings will work in other area of cylinder. When the engine is run, the rings does not rotate or rotate very little............(I read it in Forums and ClassicMechanics)
I can Take off the cylinder block is more easy work for me(I have other o´rings and other cylinder gasket) but I do not know what I can do, 

[Bryanj]

It has been proven before that rings rotate arround a piston, ialso if they did not why is it necessary to peg two stroke rings.

In a marine diesel with a 1 meter bore and 2 meter combined stroke running at 110 rpm the rings rotate 4 to 6 times every hour---as proved by Doxford on an experimental engine in the late 60's

[ka-ja]

Hi,
    A gentle bit of cross hatching with some wet+dry will help the rings bed in again

[Piki]

Ok guys, I will take off the cilynder block and remove the gasket and 4 o´rings.......
Thank you for your attention.