Hi Guys.
I heard an interesting thing the other day, and it regards changing the valve stem oil seals with out removing the cylinder head.
Obviously the cams need outing as do the spark plugs.
So you can either make a spark plug with a bsp fitting on it and a hole through the old plug screw back in to the cylinder you will work on and compress the cylinder with air, which keeps the valves shut, the colletts can be removed, and springs, oil seal removed, and pop the new one on ....But keep the pressure on in the worked on cylinder.
Alternatively, take out plug, and with the cylinder at bdc, push a long length of soft string into the cylinder, leaving a tail out to pull later. Then, by hand, turn the engine till the string compresses the valves against the string/top of cyl head/valves, then the colletts can be removed and so on...Then once done, turn the engine back the opposite way just to slacken off then pull the string out, hoping some gremlin hasnt knotted it up for you!!
I guess thats all very well, until you either loose the string, or the mrs trips over the air line hose.... by by valve... then it is head off job, but in principle it has worked.

 

I think you've got to have a bad leak to chance doing that. If the seals are leaking then it's certainly time the head came off anyway so the guides and valves can be checked and replaced/lapped if necessary. That should not be before 50K at the earliest, unless you've been tracking of course.
Nice thinking though. Thanks for sharing. You never know when that knowledge may manifest.

 

That procedure has been around for a long time. The hard part is compressing the spring far enough to get the keepers out and back in.

 

I also think, if you are going down that route, I would be happier to remove the the head. In actual fact the whole idea of string etc fills me with dread .