Very cool, thank you.
+1 I just did this a few weeks ago. 66pics in all (IO-540) and it took a bit of practice but wasn’t difficult. The hardest part was collecting all the pics off my phone and renaming them using Savvy’s file convention for upload to their site. I already has a break-down subscription but upgraded my accpun5 account it so they would analyze all the pics.
Hope so. You don’t know until the machine shop gets it. Fingers crossed.
. Had low compression and hissing in the exhaust on two cylinders in my Hatz. Lapped them in place and all was well again.
How so?
Post #18.
Same question but I'll ask it differently. What specifically do you think those IAs from Post 18 will learn from this?
That lapping is a viable option until the valve turns green and starts coming apart. They both wanted to overhaul the cylinder as I understand the story.
Or maybe in their experience lapping tends to be a temporary fix at best? Actually, I’m pushing more toward the lapping method used in this thread then anything else. What I also find interesting is there is no mention of trying to stake the valve first. Regardless, while the OP has an E/AB, would you use this in place lapping method on your engine to correct a problem?
I would absolutely try lapping a valve in situ before pulling a cylinder. I will freely admit though that most of my knowledge is theoretical.
So what would be the Part 43.13 reference you'd use to sign off the in-place lapping?
So what was your reference for signing off lapping those valves? The only place Lycoming references lapping valves that I could find is in SB301, and it says that it shouldn't be needed, but if you do it, make sure to clean up well. I'd argue that valve lapping is such a standard and well known procedure that referencing manufacturer guidance is not needed. No one references manufacturer's guidance when changing oil. Many things are just logged with a good description of the work, leaning on "other methods, techniques, and practices acceptable to the Administrator". The only thing novel here is doing it with the cylinder in place, and even then, Lycoming tells you how to remove the valve with the cylinder in place if you need to ream the guides.
Ha. I asked first. However, Part 43.13 is a performance standard, ie., how you perform the task, and is different than what reference you state in your mx record entry which falls under Part 43.9 guidance. So considering SB 301 has you remove the cylinder for the valve work and SB 1425 has you leave the cylinder installed for reaming a valve guide, how would you connect the two to meet the Part 43.13 performance requirement?
Staking is using a "fiber" or soft metal drift and placing it on the rocker directly above the valve stem and hitting it several times with a small hammer. However, once you do that you need to pull the prop through one revolution to make sure the valve reseats properly. Its always best to stake before any other task even though you have only a 50/50 chance it will do anything. But if you're lucky it can dislodge a piece of carbon or other debris that was holding the valve open.
If you think you're having valve issues get a copy of SB 1425 and follow its recommendations prior to the reaming part. Keeping your oil clean along with several other items can help manage a number of valve issues sometimes.
