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O-540, Sam James Plenum, and Oil Filler Neck

flybill7

Well Known Member
Friend
Just about to install the Sam James plenum and realized that with the O-540's oil filler neck on the top of the engine, either I'll have to remove the top cowl and plenum everytime I want to check the oil, or I'll have to cut a hole in the plenum, which kind of defeats its purpose. Has anybody out there come up with a creative solution?
 
I added a simple sliding door to access mine:

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What I did, using the inside of the plenum as a form (packing tape as the release).

This was my first RV-10 build. On the new build I’m still using the James Cowl and plenum but modified for the IO-540 Cold Air Sump.

Of note Jimmy at James Cowl can provide similar parts.
Carl
 

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What I did, using the inside of the plenum as a form (packing tape as the release).

This was my first RV-10 build. On the new build I’m still using the James Cowl and plenum but modified for the IO-540 Cold Air Sump.

Of note Jimmy at James Cowl can provide similar parts.
Carl
How did you seal the bottom of the oil dip stick tube?
 
How did you seal the bottom of the oil dip stick tube?
Simple. With the dip stick out I found a scrap piece of PVC pipe that was a close fit to go over the dip stick tube. I cut a hole in the bottom of the fiberglass well to fit the other side of the PVC pipe. With the plenum on and PVC pipe in the well, the PVC pipe is trimmed to length. Dip stick back in and just a touch of RTV between the PVC pipe and inside of the well. Done.

Side note, Jimmy at James Cowl has (or will soon have) pre-made wells and fiberglass tubes.

Carl
 
Thought about doing the “dipstick well” thing, but I was concerned that movement of the upper lid due to pillowing or anything else might pop the dipstick off. If it was screwed on, less concern, but the 540 dipstick is only held in place with an Oring. Also didn’t like the (admittedly slight) loss in plenum volume.

Is there any chance the lid can pop the dipstick off in flight?
 
I sunk mine a little farther down on the dip stick tube then found a big rubber grommet to seal it off. Be mind full the cut out is needed for hidden oil door hinge clearance
 

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This started it's life as a Sam James plenum for a RV10 then I modified it heavily to get the fit. I did make a mold of it once it was completed then made the carbon lid. I could make another if your lid if your interested.
 

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I molded a recess into the plenum to match the oil door in the cowl


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I would replace the bottom of the scrubber box with a sheet rubber. The cowl is fixed in position the engine is not: you need to provide for the engines movement especially on start up and shut down. The way it is you may find it would pop the filler stick out because of the relative movement.

Please disregard my stupid statement here; the plenum is solidly attached to the engine, so there is no relative movement.
 
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I would replace the bottom of the scrubber box with a sheet rubber. The cowl is fixed in position the engine is not: you need to provide for the engines movement especially on start up and shut down. The way it is you may find it would pop the filler stick out because of the relative movement.
The plenum is not attached to the cowl. It’s part of the engine. They move independently.
 
I sunk mine a little farther down on the dip stick tube then found a big rubber grommet to seal it off. Be mind full the cut out is needed for hidden oil door hinge clearance
Al and Richard
Beautiful work. With a recess like you both have, I was concerned about debris, moisture, etc. getting funneled down into the oil fill hole.

Has that been an issue at all? I have a hole cut in the plenum top and a rubber donut to seal the plenum to the cowl. But I like your method for absolute sealing and to prevent some small amount of engine vibration transferred to the airframe.
 
Al and Richard
Beautiful work. With a recess like you both have, I was concerned about debris, moisture, etc. getting funneled down into the oil fill hole.

Has that been an issue at all? I have a hole cut in the plenum top and a rubber donut to seal the plenum to the cowl. But I like your method for absolute sealing and to prevent some small amount of engine vibration transferred to the airframe.
So far no but only have 15 hrs on it. The filler neck sticks above the grommet about 3/8" so it's not really that easy for dirt to fall in or get pushed in. Seams to be easy to keep clean and to wipe around it with the dip stick install.
 
Al and Richard
Beautiful work. With a recess like you both have, I was concerned about debris, moisture, etc. getting funneled down into the oil fill hole.

Has that been an issue at all? I have a hole cut in the plenum top and a rubber donut to seal the plenum to the cowl. But I like your method for absolute sealing and to prevent some small amount of engine vibration transferred to the airframe.
Thanks!
No it has been fine in service. Around 400h.
It stays pretty much spotless. Occasionally I get a drip or two of oil while filling or checking.
The one thing I have to be very careful with is ensuring that I leave the dipstick in when I’m removing or installing the screws. I have nightmares about dropping one down the dipstick tube!
I have thought a bit about alternatives like skybolts perhaps. But haven’t done anything about it as yet.
 
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