FWF at 550

I got back from a lunch flight today with 551 hours on the clock, so I figured it was time to drain the oil yet again. My intent was to let it drain overnight and head home to get stuff done, but about the time I got the cowl off and the drain hose on, I heard rain on the hangar roof, and (since I was riding the motorcycle) I was stuck there for awhile. Looking for other stuff to do, I realized that it had been 150 hours since I'd checked the plugs, so I pulled those for cleaning, gapping, and rotation. Since I had the plugs out, I figured "why not check the timing?" since that had been untouched since the last condition inspection. One thing lead to another, and although I still have to put oil back in tomorrow, I basically pulled a complete FWF condition inspection before I headed home.

I am still mighty impressed at the maturity of th overall design. My FWF is bone stock (except for some extra reinforcement on the baffles), and I found very little to no wear or issues except for a groove being worn into the number four cylinder oil return line. This was caused by the safety wire ( running through nylon hose) that holds the fore and aft baffles tight underneath the cylinders. It's interesting that the nylon was wearing a hole in the aluminum, and not the other way around. I plan to give that a very careful inspection tomorrow with a good light, when it is cooler, and see if it is serviceable as-is until I can get a replacement.

I still have very few oil seeps after 20 months of flying, with only a few drips here and there to remind me that, after all, this is still a Lyclone - if it's not leaking, it doesn't have any oil in it! The Mag timing had drifted about 2 degrees early (I had checked it last October, and it was close enough not to fuss with), so I loosened up the nuts and reset them precisely - it gave me a chance to use my little laser pointer that clamps on the ring gear - too cool! I got extremely lucky in that after I tightened the nuts back up, the timing was as close to perfect as I have ever seen it - usually I screw it up a touch when the clamps move the mags as they are tightened.

The air box is still in good shape - the repair I did to the carb heat arm a few months back (drilled a new hole for the bug nut holding the cable) hasn't worn at all. If I can get another 450 hours out of it like the first one, I'll be a happy man! After seeing the thread on exhaust cracks the other day, I looked very carefully at mine, and it's in great shape at all. I think part of the reason I've had good luck is that I built carefully to have no pre-load in any parts that are fastened together. Fasteners hold things together, they don't PULL things together.

The oil screens and filter are clean as whistles - no metal or carbon particles that I could find. All the wiring looks new - no chafing or fraying. I really like having a clean engine compartment because it makes inspecting things like wiring so much easier, not having to deal with grime. I am also very impressed that the baffles are holding up so well - I had an awful lot of cracking on my old Grumman baffles in the equivalent time...once again, lack of preload probably heps in the wear department. The area around my oil cooler is also built like a tank - maybe that's why I have a slightly heavy left wing.....

I'll finish up tomorrow morning with fresh oil, safety wire on a few things, fix that rubbing oil line, and do a quick compression check before buttoning things up. It really doesn't take long to do a thorough inspection when you've kept things in good shape, and I try to do it every 100 hours or so. I'm curious how long I'll go on these Mags....I always considered Slicks to be "throw-aways" whose life started to ebb about 500 hours. They seem to still be doing great though, so I'll fly until I suspect a problem.

Just thought folks might want to know that if you stick to good practices and simple principles, these things can be trouble free!

Paul

Paul - I admire your diligence in maintaining your aircraft and hope you keep it up. It sounds like you enjoy it. But Yikes! That sounds like a lot of work and attention to detail. I myself am still struggling just to get the empennage from not looking too bad... I am beginning to wonder what engine work will be like.

--JCB

if it's not leaking, it doesn't have any oil in it!

Great, now I'm pondering how one would hang a Wasp on a -8. Thanks a lot.

Oil Return Line Wear

Here's a picture of the wear I found. The first is how the lines and the safety wire (inside the nylon tubing) were routed. The second is with the tubing pushed away, and shows the groove in the oil line. (The primer line on the other side of the nylon tube was not actually touching it, and I opened up the clearance even a bit more.)





The groove was not all the way through, so until I soure another one, I slit a piece of black automotive fuel hose and put it around the oil line to act as a chafe guard. I'm still amazed that the nylon wore through the aluminum, but I think that little bit of oil film from somewhere else picked up some aluminum oxide and acted like sandpaper....that's the dark gray mess that you see.

I had the exact problem..resulting in replacing 2 of the return lines... My solution was as yours with a peice of hose slit and placed over the lines...
Sheldon

Alternate security

Another method to consider: 2 properly sized rubber insulated adel clamps bolted together around both the oil tubes and the nylon tube to hold them at a set distance apart.

just my 2 cents from a new guy in town..

Bill

WilburD2 said:

Another method to consider: 2 properly sized rubber insulated adel clamps bolted together around both the oil tubes and the nylon tube to hold them at a set distance apart.

just my 2 cents from a new guy in town..

Bill

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Not a bad idea Bill, but in this case, the only reason for the nylon tube is to house the safety wire that is holding the baffles together, and I think I'd end up with too much tension in the system. I frequently use your method to separate two tubes though - I like Adel clamps for fluid lines!

Paul

Instead of a new tube

Why not simply cut out the grooved part and use a 2" length of fuel hose and 2 hose clamps.

I am SOOO cheap...

Frank 7a

frankh said:

Why not simply cut out the grooved part and use a 2" length of fuel hose and 2 hose clamps.

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And ruin the artistry of one of Mahlon's engines?!? Surely, you jest....(but it would certainly work!)

Nylon is tuff stuff

Just FYI, nylon is the aramid polymer family big brother to kevlar.
Extremely strong, tough, and chemical resistant. Everything plastic
would be nylon if only it did not have its "quirks".

Kerry Stevens

Nylon wire ties can cut 4130 motor mounts. According to what I've read, it's the grit picked up in normal operations that actually does the cutting. It gets embedded in the plastic & creates a cutting tool.

I had an old starter cable with a cloth jacket cut an oil line return line several years ago.

FWIW...

Charlie

rv7charlie said:

Nylon wire ties can cut 4130 motor mounts. According to what I've read, it's the grit picked up in normal operations that actually does the cutting. It gets embedded in the plastic & creates a cutting tool.

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This is why I cut all my wire ties off the motor mount and reinstalled them with a piece of bicycle inner tube under them.



Kent

kentb said:

This is why I cut all my wire ties off the motor mount and reinstalled them with a piece of bicycle inner tube under them.Kent

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You may have made it worse. The softer the material, the easier for particulate to embed in it and become an abrasive pad. I had the soft rubber seal on my truck's camper shell completely wear through the tailgate steel. One good solution to motor mount clamps is wrapped cord.