---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Sun 11/04/12: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:27 AM - Re: Air box mod to fix filter deformation (Denis Walsh) 2. 09:07 AM - Re: Air box mod to fix filter deformation (William Dean) ________________________________ Message 1 _____________________________________ Time: 06:27:20 AM PST US From: Denis Walsh Subject: Re: RV-List: Air box mod to fix filter deformation An excellent post. I would like to add a few comments. =46rom the pictures, it appears to be the same as for my carburetor Lyc 180 HP, in my RV-6A. I would highly recommend that all who have the O-360 air box do this modification, and also replace the filter when it no longer fills up the air box space, just as you did. My experience with the K&N filter and air box on my 180 HP O-360A1A was very similar. While mine did not curve, it definitely shrank, which presented the same problem. the vertical shrinkage caused a "failure to seal" at the top. The diameter also shrank. The combination of the two caused the filter element to have a lot of rattle space within the air box enclosure. As the years went by, i noticed the bottom of the fiberglass box was showing a lot of wear, and the filter element was apparently shrinking! It seemed to rattle around in the box a little more, each time I opened it up for its 100 hr cleaning and re oiling. My first action was to install a bottom plate, which looks just like yours, although i used a heavier thickness. It helped seal the top and bottom but did not help the "shrinking radius" problem. Nonetheless I did notice a reduction in the silica amount on my next oil analysis. Later on, I noted the shrinkage problem as such and replaced the filter with a new one. At this point I was able to hold the new filter next to the new one and verified it had indeed shrunk in all dimensions! Strange but true. I wish I could give you a time estimate on how long between filter changes but I can't. This type thing I just replace on condition. I believe I am on my third filter at 2,830 hours. So I would guess they lasted around a thousand hours each. I will note that they were in great condition otherwise. Those things will last forever, if you clean them gently. It may well be unrelated that my air box is sealed like yours, and the fact that my engine is still purring at 2,830 tack hours, but on the other hand it may have helped? D Walsh, RV 6A, flying for 15.5 years. On 3Nov, 2012, at 4:18 , Carl Froehlich wrote: > All, > > This is a mod to the air box I did on the RV-10, and just now back fitted onto the RV-8A. > > Over the years with the RV-8A I=92ve had to repair the air box and replace the filter. As you can see from the first photo, the bottom of the filter deforms (curves in). This tends to shorten the filter such that it drops out of the top and impairs the seal with the top plate. I also had to add fiberglass to the bottom of the air box as the relative motion between the bottom of the air filter the air box eroded away the fiberglass bottom. > > The fix was to add a .032=94 aluminum plate to the bottom of the air box. The plate eliminates the bottom erosion and the added brackets hold the filter shape. A side benefit is that alternate air door now sandwiches the bottom fiberglass between two piece of metal making a sturdier install. I also took the step to add proseal between the aluminum plate and the air box bottom. > > Carl > ________________________________ Message 2 _____________________________________ Time: 09:07:41 AM PST US From: William Dean Subject: Re: RV-List: Air box mod to fix filter deformation Please remove billoves2fly@yahoo.com from your email list.=C2- He passed away on October 29, 2012.=C2- =0A=C2-=0AThank you. =0A=C2-=0AThe Dean Family=0A=0A=0A=0A________________________________=0AFrom: Denis Walsh =0ATo: rv-list@matronics.com =0ASent: Sunday, Novembe r 4, 2012 8:26 AM=0ASubject: Re: RV-List: Air box mod to fix filter deforma tion=0A=0A=0AAn excellent post. =C2-I would like to add a few comments. =C2-From the pictures, it appears to be the same as for my carburetor Lyc =C2-180 HP, in my RV-6A. =C2-I would highly recommend that all who hav e the O-360 =C2-air box do this modification, and also replace the filter when it no longer fills up the air box space, just as you did. =0A=0AMy ex perience with the K&N filter and air box on my 180 HP O-360A1A was very sim ilar. While mine did not curve, it definitely shrank, which presented the s ame problem. =C2-the vertical shrinkage caused a "failure to seal" at the top. =C2-The diameter also shrank. =C2-The =C2-combination of the tw o caused the filter element to have a lot of rattle space within the air bo x enclosure.=0A=0A=0AAs the years went by, i noticed the bottom of the fibe rglass box was showing a lot of wear, and the filter element was apparently shrinking! =C2-It seemed to rattle around in the box a little more, each time I opened it up for its 100 hr cleaning and re oiling.=0A=0AMy first a ction was to install=C2-=C2-a bottom plate, =C2-which looks just like yours, although i used a heavier thickness. =C2-It helped seal the =C2 -top and bottom but did not help the "shrinking radius" problem. =C2-No netheless I did notice a reduction in the silica amount on my next oil anal ysis. =0A=0ALater on, I noted the shrinkage problem as such and replaced th e filter with a new one.=0A=0AAt this point I was able to hold the new filt er next to the new one and verified it had indeed shrunk in all dimensions! =C2-Strange but true.=0A=0AI wish I could give you a time estimate on ho w long between filter changes but I can't. =C2-This type thing I just rep lace on condition. =C2-I believe I am on my third filter at 2,830 hours. =C2-So I would guess they lasted around a thousand hours each. =C2-I wi ll note that they were in great condition otherwise. =C2-Those things wil l last forever, if you clean them gently. =C2-=0A=0AIt may well be unrela ted that my air box is sealed like yours, and the fact that my engine is st ill purring at 2,830 tack hours, but on the other hand it may have helped? =0A=0A=0A=0A=0A=0AD Walsh, RV 6A, =C2-flying for 15.5 years.=0A=0A=0A=0A =0AOn 3Nov, 2012, at 4:18 , Carl Froehlich wro te:=0A=0AAll,=0A>=C2-=0A>This is a mod to the air box I did on the RV-10, and just now back fitted onto the RV-8A.=0A>=C2-=0A>Over the years with the RV-8A I=99ve had to repair the air box and replace the filter.=C2 - As you can see from the first photo, the bottom of the filter deforms ( curves in).=C2- This tends to shorten the filter such that it drops out o f the top and impairs the seal with the top plate.=C2- I also had to add fiberglass to the bottom of the air box as the relative motion between the bottom of the air filter the air box eroded away the fiberglass bottom.=0A> =C2-=0A>The fix was to add a .032=9D aluminum plate to the bottom o f the air box. =C2-The plate eliminates the bottom erosion and the added brackets hold the filter shape.=C2- A side benefit is that alternate air door now sandwiches the bottom fiberglass between two piece of metal making a sturdier install.=C2- I also took the step to add proseal between the aluminum plate and the air box bottom.=0A>=C2-=0A>Carl ive Search ==== ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rv-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RV-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rv-list Browse Digests http://www.matronics.com/digest/rv-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.