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-   -   Making a Little Bit of Metal (https://vansairforce.net/community/showthread.php?t=135233)

Jerry Fischer 06-11-2017 06:40 PM

We need to save him ...
 
Quote:

Originally Posted by DanH (Post 1179507)
Ahh...a wonderful opportunity to learn all about the inside of your engine.

There, doesn't that feel better?

a beer Sunday @ OSH Dan...:D

Jerry Fischer 06-11-2017 06:46 PM

Try...
 
Quote:

Originally Posted by MartinPred (Post 1179634)
I bought this engine as a zero-time overhaul from Ly-Con. I presume they're stock, but I can't really say.

Can anyone recommend a good shop that can overhaul a cam? This engine only has 800 hours on it and so far everything else is looking pretty good. I plan to just IRAN everything as I take it apart.

-Matt

Phil Scadden @ Phil's cylinder service, he may be able to recommend a shop as he built the cylinders for my RV7. He's in Brookville Ohio outside Dayton. 937-833-0843

tim2542 06-11-2017 07:28 PM

Quote:

Originally Posted by MartinPred (Post 1179634)
I bought this engine as a zero-time overhaul from Ly-Con. I presume they're stock, but I can't really say.

Can anyone recommend a good shop that can overhaul a cam? This engine only has 800 hours on it and so far everything else is looking pretty good. I plan to just IRAN everything as I take it apart.

-Matt

Sorry for more bad news, but I can just about guarantee that cam will red tag, especially if it's a custom grind as Lycon is likely to do, it's already been ground at least once, it's probably not worth the shipping cost to find out. Same with the followers. You can get a kit with or without hydraulic assemblies, they can be swapped out later if you don't want to spend the money now.
Start shopping for a new kit. Sorry to be a wet blanket, but once you split the cases on one of these it's very hard to find a place to stop short of an overhaul and remember you've had steel circulating throughout the engine, most of which will have been trapped by the filter, but not all. For example you'll want as a minimum new main bearings, and its probable you'll find the case halves fretted and in need surfacing and line bore. The oil pump will likely have damage from the unfiltered oil passing through it.
Don't get me wrong, you can split it, replace the cam and go right back with same parts, but the investment in time and money to get the cam swapped out, it may make better financial sense to go back with a completely sound engine, cylinders of course considered separately, everything else yellow tagged, remachined and ready to go another 2000 hrs.
Tim Andres

Jeff Hagg 06-12-2017 06:43 AM

Metal in oil cooler
 
Replace your oil cooler and lines as well or you will be doing all this over again and again.

sblack 06-12-2017 11:28 AM

Quote:

Originally Posted by Jeff Hagg (Post 1179783)
Replace your oil cooler and lines as well or you will be doing all this over again and again.

Why? Because they are contaminated with metal? I have not heard this advice before. Can you elaborate?

sblack 06-12-2017 11:29 AM

This is why I kind of chuckle when I hear guys say "this engine has only 500 hrs on it - that's 1500 left". Well, maybe, but probably not.

Boyd Birchler 06-12-2017 12:44 PM

Lycomings like to eat the front 2 cam lobes. Have seen it many times, at least twice on my own engines. I have had just as good of luck just replacing cam (new) and the 3 bad lifters as I have had doing a complete major. Of course take a look at the oil pump gears and housing. I have never, so far, seen any damage from the small amount of metal lost from the lobes on the crank or rod bearings. I did see one oil pump housing with minor scoring, that I did replace ( it was definitely still serviceable).

A&P/IA

theduff 06-12-2017 01:00 PM

LyCon Camshaft
 
The cam in the picture has been reworked by firewall forward with their "centralube" oiling modification. The cam has an internal oil passage drilled through it with the holes on the face of the cam lobe providing additional lubrication during operation and more importantly during cold starts.
It was developed to prevent this exact failure mode " spalling" from happening. Lycoming switched to roller tappets for this very reason. LyCon was a big proponent of these cams before the roller tappets and unfortunately they are not fool proof. That camshaft and follower are a very expensive piece of junk.
When you rebuild the engine and if you stay with flat tappets use the newest design Lycoming flat tappet as they have a hard facing that has all but eliminated this problem. Do send your cooler out for rebuild and have all your oil lines remade or professionally inspected and cleaned as you will be chasing a lot of metal around trying to get rid of it all. Any Ferrous metal remaining will soon fail the new engine, surgically clean is almost clean enough !


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