FWF inspection at 80 hrs

With the weather turned really bad, I decided to take a serious look at my RV7a FWF installation after 80 hours. I typically look everything over at 25 hr oil changes and when in phase one, all the time. These typical inspections look for fluid leaks, loose stuff, and anything that looks out of order. With this inspection, I looked at every wire, hose, cable, bolt, clamp, ect.... A very through looking at. Following is what I found:

First, When I decowled, I noticed some oil dripped or splattered on the lower cowl in the front left corner. Also,there are two rub marks, one I was aware of and one that is new.



The big one on the front is from the snorkel I custom built. I miscalculated the clearance between the two and have known for some time that this was rubbing. I plan to remove the snorkel and rebuild it. The second new rub is at the very bottom of the photo on the right side from an exhause hanger that has moved. Need to take a look at that.

Here is a closer look at the rub and the offending hanger.






Next photo shows the oil on the starter right above the drips. Looks like it might be from the cylinder base? Not sure and will need to look deeper. Can the cylinder bolts be re-torqued?




Next 2 photos are more disturbing, showing blue fuel stains at the spider. Need to research this, know there are SB on these plugs. Any help to send me in the right direction would be appreciated.





Next is a photo of the RV crack! At the oil cooler mount, I already did the Van's recommended doubler and I had installed the recommended brace from the oil cooler to the center case bolt. The baffel still cracked and the brace also cracked at one end. I am replacing the brace with a steel tube and will reinforce the corner. Should I replace the cracked baffle also or is the reinforcement enough. A new baffle piece is only about 11 bucks but it will involve painting etc. (I'm thinking I will)



I also found that the mixture cable had moved and is just starting to rub on the engine mount. I can install a set of Adel clamps to take care of this.



All of my exhaust gaskets are dry except this one. It may be leaking or the source of the very thick black stuff may be from above and just baking on the exhaust. Need to get in there with mirrors and lights.



That is the extent of what I found during this very extensive inspection. I will report the fixes and discoveries when I am done in a week or two.

Good job on your inspection. I would suggest you do this thorough of an inspection every time you do an oil change. That crack in the baffle did not happen overnight.
In regard to the baffle support. I added another .040 doubler bent in an angle (know your bend radius limits) and reinforced that area on the outside where you have the crack. (in hind sight, I should have done the other side, back baffle, as it cracked after about 500 hours). I repaired it with an .040 angle. Also, I used a piece of .025 angle spanning the length of the oil cooler flange on both sides in addition to the washers. I also used a 4130 steel brace I fabricated out of some tubing that runs from the back baffle inside corner to the case.
I do not believe there is an acceptable repair to your current baffle. I would replace it and make the above mods or follow some of the others that have done it in different but successful ways.

My spider had a small amount of blue staining early on, but less than yours. It has since "dried up". They use fuel lube on these plugs and it must allow some small amount of seepage. I do not know what is acceptable and what is not. Mine are tight and do not seep anymore.

JonJay,

Correct on the crack, it started as a crack between two rivets at about 40 hrs and I have been watching it closely. The support brace broke and the crack developed into this in the last 8 hrs. I have been intending to fix it at annual if it didn't change until then. This is a major change and needs fixing.

The blue stains may have been present in a very small way but not enough to get noticed. This time they were screaming at me. I have no doubt that they may have been leaking in some form for a long time, but not enough to get my attention. There wasn't the blue stains present like this until now. I typically go over everything fuel and oil related everytime I pull the cowl, and I have the top cowl off frequently. I run my fingers under every fitting.

As far as the oil leaks, the cowl has been totally clean until this time. I usually wipe down the inside with a clean cloth and a little paint thinner everytime its off.

What's interesting about the oil on the starter is that it's black. The oil on the bottom of the cowl is clear to honey colored. Have to think about what this means. Different sources?

The only difference in the last 8 hrs from the last inspection, is that I have flown it in very cold temps. As low as 5 ?f. Pryor to that, always in warm temps. Could that have anything at all to do with any of this?

Paul - good to know you are keeping a diligent eye on things. I will let the engine and maintenance experts chime in on the fuel stain and oil leaks.
When I had the small show of fuel weeping out of the plugs I checked them and they where tight.
My only thought on the dirty oil is that flying in the extremely cold weather may have allowed some oil to make it past the prop seal. It doesn't take much. Probably just something to watch.
It didn't look to me like there was enough oil to worry too much about. I know there are those here that have perfectly dry lycomings but I am not one of them.

Thanks for the inspection report, Paul. I had wondered about the durability of the aluminum brace, as I had just read about to others that were made from tubing. I will be moving to the baffles soon and this us useful information.

On the black oil. It seems that there is a small about of oil but there is movement or heat causing it to be black. RocketBob might be a good guy to comment. You built this engine didn't you? Isn't there an oring a at the base, and no sealant to be used there to ensure good metal-metal contact? It appears that the cylinder base has relative motion. Motion is not good for these parts. Mark the nuts before you attempt to retorque so see if they move, and now much. If they move, consult your engine guy.

The more clear oil seems to just be minor leaks. Not serious, but I would fix them to keep the under cowl clean.

I reviewed your oil cooler reinforcements and thought that was nailed! I will follow your modifications with interest.

JonJay,

I too have never owned a dry Lycoming! Not even close. And you are correct, there is a very small amount of oil present.

I checked the back side of the starter ring and it is dry. Also checked the front side of the baffles and they are dry as well as the top of the top cowl. I can't find any evidence of the prop seal leaking. The whole front end is dry except for this issue.

BillL,

Yes, I built the engine under the watchful eye of a very well known engine builder. There is no sealant at the base of the cylinders. I also cleaned part of it off and upon very close inspection, there does not appear to be any movement at the cylinder base.

On the crack, I am going to replace the cracked baffles and the doubler if it is cracked. I will also install a heavy angle using the rivet holes from the existing baffles and oil cooler nuts, and installing a second set of rivets into the side baffles. Finally, a steel tube will replace the aluminum angle brace.

All repairs and changes I wanted to make are well on the way to being finished. One question I had that couldn't be answered until disassembly, is if the crack in the side baffle CB-1004A was all the way through to the other components of the assembly or just in that one piece? After drilling out all the rivets and unbolting the accessories and attachments, I have the answer!

Its just the side piece CB-1004A. The rear baffle, oil cooler doubler, and the FF-713 spacer are all fine.

Here is a photo of the side CB-104A. Cracked almost all the way top to bottom.



This is the FF-713 Spacer, No cracks and looking good.



Finally is a photo of the CB-705A rear Baffle. No cracks at all.



I didn't take any photos of the FF-709 Doubler but it is also crack free.

While doing the removal of this assembly, I discovered a little oil between the side baffle and the head. Just in one place. Discovered a loose screw in the valve cover. Rechecked all the screws in all 4 covers and many of them were loose! I hadn't thought to check these but they are now added to my maintenance list.

More later.

Paul K said:

All repairs and changes I wanted to make are well on the way to being finished. One question I had that couldn't be answered until disassembly, is if the crack in the side baffle CB-1004A was all the way through to the other components of the assembly or just in that one piece? After drilling out all the rivets and unbolting the accessories and attachments, I have the answer!

Its just the side piece CB-1004A. The rear baffle, oil cooler doubler, and the FF-713 spacer are all fine.

Here is a photo of the side CB-104A. Cracked almost all the way top to bottom.

This is the FF-713 Spacer, No cracks and looking good.

Finally is a photo of the CB-705A rear Baffle. No cracks at all.

I didn't take any photos of the FF-709 Doubler but it is also crack free.

While doing the removal of this assembly, I discovered a little oil between the side baffle and the head. Just in one place. Discovered a loose screw in the valve cover. Rechecked all the screws in all 4 covers and many of them were loose! I hadn't thought to check these but they are now added to my maintenance list.

More later.

Click to expand...

I would add some reinforcement to the back baffle on the inboard side of the oil cooler. You are reinforcing the entire corner and making it stiffer as well. The vibration and force has to go somewhere and it will go there in my experience, just inboard of where your brace screws too on the back baffle, assuming it attaches right next to the cooler. It took more than 500 hours for mine to crack there, but it eventually did. All fixed with one piece of .040 angle.

Valve cover screws loose? They should be very lightly torqued or you will deform the cover and loose your seal and more leaks will propogate. I "feel" check mine every time the cowling comes off. After a while, I may find only one or two that need, ever so lightly, tightening up. I also switched to silicone gaskets. Highly recommend that if not already done.

JonJay,

Thanks for the advice on the additional reinforcing. Will Do. Don't know if I had mentioned it but the aluminum angle I had used for the oil cooler brace from the center case bolt had also cracked at the engine side. I'm changing that to steel tubing left over from a tube and fabric build a friend did.

Many of the screws were loose, the one that had oil next to it was finger loose! Don't know how that happens but will watch them in the future. I have the cork gaskets, will order a new set of silicone gaskets and install them at the annual in just a few months.

Paul K said:

JonJay,
Many of the screws were loose, the one that had oil next to it was finger loose! Don't know how that happens but will watch them in the future. I have the cork gaskets, will order a new set of silicone gaskets and install them at the annual in just a few months.

Click to expand...

I tried the "Real Gaskets". Very nice product, but the ones I received where much thicker and a bit wider. The thickness was not a problem, but the width was. They overlapped onto the edge of the baffle causing them to not sit down correctly, or at least I did not like how they fit. I ended up finding OEM Lyc silicon ones that where exactly the same width as the cork.
Just something to look out for.

Paul,

You have one oil cooler mounting hole on the outboard side that you have not used. In between the two with the aluminum spacer tubes. I'm thinking those rather long bolts through the tubes may move slightly under extreme vibration allowing a leveraging component to be added to the vibratory forces acting on the nutplates where the baffle cracked. I wonder if adding a third short bolt (with washers under the nut/head) would help prevent cracks? The nutplates don't have as much of a "washer" component on their sides as a regular washer does to spread the load. Just a thought.

Bevan

My oil cooler is installed with three bolts on the outboard side, the Vans-furnished later-style doubler, AND an additional .063 doubler that goes all the way around the oil cooler opening ... that I fab'd up after I read about the cracking problems others had. No guarantees, but I have no evidence of cracking after 110 hrs.

Also on the flange cracks from the oil cooler, it looks as if there's no structural connection between the cracked flange and that reinforcement angle at the top left of the photo.



Perhaps there is but it's out of the picture. Still, if there isn't anything, it's worth adding something to transfer the out-of-plane loads on the flange to that angle. A thick bracket made from a piece of angle, with the upper oil cooler nutplate mounted to that (so that the flange is sandwiched between the bracket and the oil cooler) and riveted to the angle shown would do it nicely. You'll need at least two rivets joining the bracket to the angle.

Dave

My plan is at this time, to add an aluminum angle vertically in the corner and extend the existing rivets through it. Then add rivets through the angle into the side of the baffle. Hopefully this will transfer some of the stress into the side skin. I am also going to connect the existing side angle to this new angle with at least two rivets using a angle clip between the two. Also will look into adding a third bolt on the outside of the oil cooler. Finally in addition to this, I am replacing the support angle from one of the oil cooler bolts to the center case bolt as a stiff arm. I had one of aluminum but it broke.

Another form of support for the entire assembly is the carbon fiber plenum that is bolted to the top of all of the sections of baffling. It was my hope that this would act as a membrane across the top and add much additional support and stiffness. Obviously, there are other forces going on here. I have yet to get my WW200 prop dynamically balanced but that is also on the ASAP list.

Paul K said:

I am replacing the support angle from one of the oil cooler bolts to the center case bolt as a stiff arm. I had one of aluminum but it broke.

Click to expand...

Hi Paul. Might this be one of your problems? I know others have done this, but the aft left baffle corner, to which the oil cooler is attached, is designed to float with the #3 cylinder. If you try to fix it to the center case you are preventing that float and thus creating stress. If one wants to use a brace, I would argue it should connect the baffle at the oil cooler to the #3 cylinder instead. That way, everything is moving in harmony. A fuller explication of this can be found in the archives here somewhere.

Having said all that, I'm not aware of anyone developing the baffle crack if they proactively reinforced that corner with angle. That's where I'd start.

Good luck.

It took much longer than expected but I am finally getting some of the issues taken care of that I first wrote about.

I ordered a new baffle section and added some reinforcement per what others have done and based on what appears to work for them. Here is a photo of the new part before installation.


Mostly added a corner angle and tied it into the side horizontal angle with a clip.

I had also removed the custom built snorkel because it was rubbing on the inside of the cowl as a result of my miscalculation.


While I was at it, I reinforced the plenum at the front inlets because they were showing small cracks in the outside corners and I just wasn't happy with the look. Here are the two rebuilt pieces before installation.


Snorkel installed.




Here is the plenum set in place to see how it looks and fits.




The carbon fiber really shows well.

I also adjust the exhaust hanger so it won't rub on the cowl, Went ahead and replaced the aux battery, Installed hot pads on the bottom of the oil pan, and repaired everything else earlier mentioned. I also inspected the rear HS spar per the very recent SD, no cracks.