If the valve guide has worn too much and the play is too great then the cylinder should be pulled and new guides installed. If it’s too tight then they can be reamed and the stems polished with the cylinders installed by dropping the valve inside the cylinder using the dental floss and safety wire trick.
You stated the maximum allowable clearance (wobble), is there a minimum clearance? My understanding is these have a tendency to get carbon build up causing the exhaust valve to stick, seems like this would be a good way to spot that as well. Great video, thanks!
There is a minimum. I forget exactly but it’s around .010” or so. Good point. If it were less than that you could investigate further and consider reaming the guides to clear out carbon coking.
It’s great that you know how to do that maintenance. And equally great that your A&P works with you so you can do it.
Thank you so much! I need to do this on my O-235 (experimental aircraft) and this is a great tutorial .
Thanks for this video. What is the work/replacement needed if the wobble isn't within limit? Change / clean the valve? Thx
If the valve guide has worn too much and the play is too great then the cylinder should be pulled and new guides installed.
If it’s too tight then they can be reamed and the stems polished with the cylinders installed by dropping the valve inside the cylinder using the dental floss and safety wire trick.
I do is I use a thin screwdriver and a dab of grease to have the valve keeper stick to it because the magnet is gonna wanna make it come back out
Thanks! Great technique! Also keeps the retainers from being magnetized.
Awesome! TY
Can you tell me what brand is your spring compressor tool. Great video.
www.aircraftspruce.com/catalog/topages/compressor2.php
You stated the maximum allowable clearance (wobble), is there a minimum clearance? My understanding is these have a tendency to get carbon build up causing the exhaust valve to stick, seems like this would be a good way to spot that as well. Great video, thanks!
There is a minimum. I forget exactly but it’s around .010” or so. Good point. If it were less than that you could investigate further and consider reaming the guides to clear out carbon coking.
The valves stick from lead build up. If able, run mogas and lean aggressively.