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Baffle Question

Edwardoc

Member
When I first installed the baffles on an IO 360 I lined the inner surface of the baffle that raps around the cylinders with mylar tape as suggested by someone on the forum to decrease the wear of the cooling fins wearing the aluminum. I removed one of the baffles for some maintenance and the tape had melted and was a mess. Does anyone have any suggestions for lining the surface next to the cylinder? There are some groves worn in some of the areas through the tape after 600 hours. I used 3/16 inch SS welding rod and bent and threaded them to connect the inner coolers together. I used nylon tubing to cover them but they melted on one side. Any suggestions on covering the rods to reduce any wear on the drain back tubes with something more heat resistant?:)
 
I have seen beads of high temperature silicone used to cushion the baffles where they touch the fins. Not in time for mine unfortunately.

For the tie rods, I covered them with a yellow fuel line used for gas powered model aircraft. I haven't inspected them specifically yet, (only 27 hrs) but the tubing is obviously designed for use around engines... It is tougher than silicone tubing and impervious to oils...
 
I glued a piece of the Vans supplied black baffle seal material to the baffles on the curved parts that wrap around the bottom of the cylinders. It seems to be holding up very well for the last 850 hours!

Jerry Esquenazi
RV-8 N84JE



When I first installed the baffles on an IO 360 I lined the inner surface of the baffle that raps around the cylinders with mylar tape as suggested by someone on the forum to decrease the wear of the cooling fins wearing the aluminum. I removed one of the baffles for some maintenance and the tape had melted and was a mess. Does anyone have any suggestions for lining the surface next to the cylinder? There are some groves worn in some of the areas through the tape after 600 hours. I used 3/16 inch SS welding rod and bent and threaded them to connect the inner coolers together. I used nylon tubing to cover them but they melted on one side. Any suggestions on covering the rods to reduce any wear on the drain back tubes with something more heat resistant?:)
 
I replaced melted tubing with fresh. Did it two times. Will do probably two more times before engine wears out :)






 
Aren't those baffle tension rods supposed to be bent to keep them off the cylinder fins?
IMG_3256-M.jpg

On mine, they do touch the oil return lines, but a dab of RTV is there to hold them from rubbing.
IMG_3268-M.jpg
 
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Aren't those baffle tension rods supposed to be bent to keep them off the cylinder fins?

That's the latest design Bruce - yes. Many of us still have the old "stone knives and bearskins" design baffles....made back when you safety-wired the lower baffles together!
 
Lower Baffle Tie Rods

Hey fellas,

On my -8 after first six or 8 months I also noticed the nylon protector tube had melted and scorched in a couple of spots. So come first condition inspection I removed that stuff and replaced it with a same diameter Teflon tubing that has a much higher temp rating, like 450 deg or so. Been in that engine compartment since 2009 and still looks spotless. No melting. I got it at some plastics store that sold all types of different plastic products for industry. Just Google up Teflon tubing and see what you find. Good luck.
 
I glued a piece of the Vans supplied black baffle seal material to the baffles on the curved parts that wrap around the bottom of the cylinders. It seems to be holding up very well for the last 850 hours!

Jerry Esquenazi
RV-8 N84JE
What type of adhesive did you use?
 
Mine are lined with 9oz plain weave glass impregnated with Loctite 598 between 4mil plastic sheets. Cut the plastic and glass sandwich to exact size, peel one side, stick it to the fins, peel the other side.

My wraps are more extensive than just baffle lining, but that's another experiment.

http://www.henkelna.com/industrial/product-search-1554.htm?nodeid=8797922295809



Many of us still have the old "stone knives and bearskins" design baffles....made back when you safety-wired the lower baffles together!

Which still works just fine. Use 0.040" wire. Note that if you tie them across individual cylinders (rather than from the front baffle wrap to the rearmost baffle wrap) they don't cross the drainback tubes, so no rubbing.

 
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I did something similar to Dan--used 8 oz plain weave glass, placed on wax paper on a hard flat surface, pressed high temp rtv into the glass with a "bondo blade", placed a sheet of wax paper on the "wet" side, flipped it over and did the back side as well (very thin layer of rtv--it will satuarate the glass), cut the wax paper/glass sandwich to the exact size, peel off the wax paper and put in place. If you use this technique, be sure to peel the paper off the glass/rtv before it completely cures or the wax paper is permanently there--don't ask me how I know!! I did this while replacing my Eci category A cylinders, so the baffles were off and easy to measure. A retro-fit might be a little more difficult.

BTW, I also lined my PC 680 battery box with this material to protect it from heat.

Hope this helps.

Cheers,

db
 
Dan,
How many layers of the 9 oz. glass are those RTV impregnated clamshells? Do you "wet" then out with a squeege like epoxy? What holds them in place?
Thank you!
 
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Dan,
How many layers of the 9 oz. glass are those RTV impregnated clamshells? Do you "wet" then out with a squeege like epoxy? What holds them in place?
Thank you!

Lay a single ply of 9 oz plain weave, on a 4 mil plastic sheet. Squeeze out a wad of Loctite 598 (or Permatex Ultra Black, same thing) on the fabric, cover with another plastic sheet, and use a roller to work the sealant into the fabric, between the sheets. When saturated, just cut the sandwich into sections of exact size, then peel one side and stick it to the fins. Peel the other plastic sheet in a day or two. None have budged in 350 hours.
 
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