What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Paint flaking off cylinder barrel. Normal? Common?

A

alpinelakespilot2000

Well Known Member
My 300-hr Aerosport Power 0-320 has a fair amount of black paint flaking off all four of the barrels, particularly on the flange that connects to the case. Is this common, normal, OK?

257hxr9.jpg
 
Steve after my tach flipped first thousand hours about two years ago I worried about this. Factory baked Lycoming only three years in service? :eek:







Imagine now after recommended TBO? I don't even want to post a picture :)
 
normal is....as normal does?!

'Normal' is for the engine to leak just enough oil to keep the metal parts from rusting!
It's a finely engineered Lycoming feature.....no extra charge! :D
 
My Warrior has a low-time O-320 rebuilt by Penn Yan. Same as Vlad's pic above. I was told by an A&P that it is very common and not to worry. Don't know if this is true but he said years ago a paint formulation change was made and flaking became common thereafter.
 
Paint

When we used to judge aircraft at the SWRFI, we quickly learned that paint was only worth a very small percent of a score. Translation= paint don't make them fly and better, just keeps them lasting a little longer. The last engine I built for myself, I spent a good amount of time prepping and painting with very good high temp engine paint. You guessed it, it flakes off too.
I know this dose not settle your concern but, this is why we work on them every week end, or so it seems. Yours as always, R.E.A. III #80888
 
Thanks for the replies. As I understand it, paint on surface contacting the case would have been a no-no during the initial build, so there should be no paint to loosen there to reduce the torque on the nuts holding the cylinders to the case, right? That was my initial concern, though having to somehow try to keep the rust away is a bit of a concern.

That said, my Aerosport has always "weeped" oil from points unknown, so things usually get a pretty good "anti-rust" oil misting eventually. :D :(
 
You got it.

Yes, if it is a factory engine they paint it after it is assembled. You are correct in, if you paint it as you go together with it, you want the flanges clean with no paint on the mating surfaces. It's not in the book, but you may want to hit that rust with a little corrosion-X from time to time. Most will rightfully tell you anything you put on the surface will change the heat exchange rate, but "I" have had good luck if this is not over done with my rust buckets.
Yours, R.E.A. III #80888
 
Robert Anglin said:
Yes, if it is a factory engine they paint it after it is assembled. You are correct in, if you paint it as you go together with it, you want the flanges clean with no paint on the mating surfaces. It's not in the book, but you may want to hit that rust with a little corrosion-X from time to time. Most will rightfully tell you anything you put on the surface will change the heat exchange rate, but "I" have had good luck if this is not over done with my rust buckets.
Yours, R.E.A. III #80888
Click to expand...
A 3 mil layer of coating like Corrosion X is less of an insulator than 10 mils of rust! Not to mention stopping the corrosion damage. Myth busted. ;) I'm with you Robert. Steel parts get some protective coating on my plane when/if the paint fails.
 
Normal....but could be important

Seems to me there was a Lycoming SB to verify that there is not paint under the cylinder bolts. If the paint flakes away under the bolt, the torque values are lost and could cause a cylinder to loosen.
In one case I know of, this happened and caused a loose cylinder and a couple of broken studs.
So, it could possibly be a big deal.........depending on where the paint is.
YMMV
 
sf3543 said:
Seems to me there was a Lycoming SB to verify that there is not paint under the cylinder bolts. If the paint flakes away under the bolt, the torque values are lost and could cause a cylinder to loosen.
In one case I know of, this happened and caused a loose cylinder and a couple of broken studs.
So, it could possibly be a big deal.........depending on where the paint is.
YMMV
Click to expand...
Thanks Steve. As noted above that was one of my initial concerns. Having said that, I can't imagine Aerosport Power would have installed it with paint on the mating surfaces, but might be worth a call to confirm.
 
You must log in or register to reply here.
Back
Top