S

szicree

Well Known Member
I've searched the archives on this, but wanted to see if anybody had any recent and slick way to do it. I've considered the suggestion of safety wiring the baffles to the inter-cylinder baffle, but am concerned about the wire eventually pulling through the inter-cylinder baffle (alum). I'm also not thrilled about having to remove them in order to reinforce. I like the idea of threaded rod with joggles, but am concerned about them rotating.

I realize I might be overthinking this one, but I really don't want a plane that constantly has squawks, and the last thing I want is a severed oil return line. Pictures or advice would be greatly appreciated.
 
Lower baffle ties

Steve,

I used 3/32 stainless welding rod and threaded it for #2 nuts. I put washers and nuts on both sides at both ends. I only have a little over 100 hours on the plane but so far so good.
 
One technique is to take the mandrel from a pop rivet, and bend one end to form an "L" with one long side and one side that's 1/4" long or so. Then, you drill two holes in what I'll call the tension tabs on the baffles. One hole is towards one side of the tab, the other hole is centered on the tab.

The short leg on the bent mandrel goes through the off-center hole in the tab, and safety wire goes through the other hole and is wrapped around the pop rivet mandrel, then doubled up and twisted along its full length to the other tension tab. Drill similar holes on the opposing tab and tie off the safety wire to that "L" after tensioning. Remember that the safety wire needs to be twisted along its entire doubled up length.

The length of the mandrel gives plenty of bearing surface so it doesn't pull through the tabs on the baffles. The end of the "L" going through a hole keeps the mandrel from rotating.

Mine have been this way for 8 years with no problems. I do have nylon tubing over the safety wire to give some level of protection to the oil return lines should they touch.
 
Pull a steel pop rivet (you should have them already).. I used the large diameter one.. from the baffle seal material... and thread the wire through it.. that will prevent it from cutting through the aluminum...
 
szicree said:
I've searched the archives on this, but wanted to see if anybody had any recent and slick way to do it. I've considered the suggestion of safety wiring the baffles to the inter-cylinder baffle, but am concerned about the wire eventually pulling through the inter-cylinder baffle (alum). I'm also not thrilled about having to remove them in order to reinforce. I like the idea of threaded rod with joggles, but am concerned about them rotating.

I realize I might be overthinking this one, but I really don't want a plane that constantly has squawks, and the last thing I want is a severed oil return line. Pictures or advice would be greatly appreciated.
Click to expand...

After 2,154 hours, I pulled my cylinders for overhaul / replacement. I used the safety wire like Van suggests with washers. They lasted 11-years and 2,154 hours with problems. There were marks in the oil return lines but no problems or cause for rejection. When I installed the new cylinders, I place a 1" piece of 3/8" hose over the one oil return line that had a mark from where the nylon guard had made a mark.

I have seen this done many different was on many aircraft. The way Van suggests is the lightest, lowest cost solution that accomplishes the job necessary.
 
Radomir said:
Pull a steel pop rivet (you should have them already).. I used the large diameter one.. from the baffle seal material... and thread the wire through it.. that will prevent it from cutting through the aluminum...
Click to expand...

Or just a #4 or #6 washer. You can use a pair of pliers to bend it in half a bit so that it will fit the contour of the intercylinder baffle, if you like.

I have been running this setup for over 100 hours and no problems. I recently redid a few of the wires (due to insufficient tension) and found no signs of pulling through.
 
I have tried the locking wire between the baffles and it touches the rear cylinder, is that normal ? Does the nylon tube not melt ?
Thanks
David
 
I used drill rod, threaded on each end, bent where required to clear the oil lines and double nutted. works great after 360hrs

Doug
RV6
 
Lower Baffle

Lower Baffle ties
What ever design of fastener you go with, a short story experience. Just lately a friend of mine that has a RV7 and has been fighting hotter than normal CHT?s at higher power settings and has tried just about everything on cowl intake and exit air flows with no success. Lastly we opened up the lower baffling through the cylinders to allow more flow through. The CHT?s dropped 20 plus degrees. Just a thought so if you change baffling exits you doesn?t have to re-engineer you fasteners.

Thomas S.
www.g3ignition.com
 
Here is a picture of my solution. I copied it from somewhere. The stainless is around steel piano hinge rod with a 90 deg bend to locate it. Its holding up well.

PS The twisted stainless runs into plastic tube. You can just see it below the EGT sensor.
 
Make sure

The plastic sleeve is nylon...Available in the brake kit or from your local hydraulics emporium..Other plastics will melt.

Frank
 
AN bolts for lockwiring

I had concerns about the holes wearing from the safety wire also. Instead of a washer, I used an AN-3 bolt and washer on each end of the baffle. The heads were on the outside of the baffle. Run the lockwire, using the nylon brake line tubing for chafing protection. The lockwire goes where the cotter pin normally would.
 
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