RAM air door missing seal

[00-Negative]

Started flying my M20E in September and have put around 40hrs on it since purchase. I noticed the RAM air door had a small gap around the top and sides. Looks the the seal is either completely deteriorated or was removed and looking back at pictures I took when I bought the plane, it was like this when I purchased it. LASAR does not have the seal in stock. I'll prob replace with baffle seal material next week. 

Here's my question:  I need to fly my wife/girls this weekend to a cheer competition. I sold them on the plane by convincing them that we would use it to fly to these competitions and we already had to drive the first one d/t weather. They're eventually going to figure out that I spent all of our money on a plane for me.  Can I cover the RAM air door opening with 3M aluminum foil tape temporarily until I replace the seal?

 

Thanks,   

David

 

[Shadrach]

You can make a seal out of rubber gasket material (1/8” IIRC). You can buy sheets of it at your local auto parts store. I would not bother taping it up unless you live in a dusty environment. You’ve been flying it as is since you bought the plane, another flight isn’t going to make a difference. Depending on environment, you might see elevated silicon in the oil from running without a gasket. It’s an easy fix. I would take care of it ASAP...
 

[00-Negative]

Yes sir. Thanks for the response. I might be able to get it done tomorrow. 

[201Steve]

1 hour ago, 00-Negative said:

. They're eventually going to figure out that I spent all of our money on a plane for me. 

Hahahahahah

[Ron McBride]

Before flying, find the old seal and remove it.  The old seal can block air going into the fuel injection system.   No air, no power…

[RobertGary1]

If be careful putting anything on it. Anything making it past (including ice, tape, etc) can go straight to the impact tubes and stop fuel flow. 

[Fly Boomer]

On 1/11/2024 at 8:32 AM, 00-Negative said:

Here's my question:  I need to fly my wife/girls this weekend to a cheer competition.

I wouldn't change anything just before the flight you describe.  If there is an incident, you won't have to worry about them "finding out eventually".

[mpilot]

Bringing this back around, as I found mine the same way after purchase. initially thought the cable needed adjusting but now am pretty certain it's just missing the seal. 

@00-Negative did you seal yours up as suggested with the gasket material, or did you get it to someone to fix?

thanks

 

Edited November 10, 2025 by mpilot

[00-Negative]

7 hours ago, mpilot said:

Bringing this back around, as I found mine the same way after purchase. initially thought the cable needed adjusting but now am pretty certain it's just missing the seal. 

@00-Negative did you seal yours up as suggested with the gasket material, or did you get it to someone to fix?

thanks

 

The final product uses 1/8" silicone baffle seal as suggested. I've replaced the seal 2x. After that flight, my A&P and I replaced the worn seal with the same material that was already in place which is a thinner, more flexible rubber material. I did find the original broken piece of seal behind the air filter. The first seal we made lasted less than 100 hours and I found it cracking again on the top. I then used the 1/8" silicone baffle material  which was trimmed to fit perfectly in the opening without bending or stressing the seal material but still touching the side walls of the RAM opening with the door fully closed. The previous thinner seal material was cut slightly oversized and flexed against the side walls with the door closed which caused it to crack in short time. The 1/8" baffle material will not allow flexion in such a short gap, so it will need to be trimmed absolutely perfectly. As mentioned in the thread above, I had elevated silicone levels in my oil analyses through the first few months of owning my plane which I attributed it to new silicone rocker cover seals, push rod seals, air filter had not been changed in 2-3 years,  replacing worn intake accordian boot, and other such overlooked maintenance items through the first several months of ownership. After the second RAM air door seal, my silicone levels came down. 

The ram air door can be removed easily without removing lower cowl or disconnecting anything. Remove the air filter and open the RAM air door nearly all the way. You can then access either 2 or 3 round head machine screws on the back of the ram air door and slide the door off of the tongue that holds it in place. There are flush rivets holding the seal in place. My A&P told me to drill out the rivets, cut a new seal, come back and we'll put it back together and re-install. I went to my shop and completely shredded the thing with terrible technique and ignorance about rivets. So we then fabricated a new door with a new seal. 

The RAM air door can easily be reproduced with hand tools. It might be a good idea while you're doing this to fabricate a completed and painted 2nd door with a new seal in place. I have compiled a hangar full of backups like this. I can remove and replace that RAM air door in a few minutes. But to remove, drill out the rivets, cut a seal, and re-install (If I have the materials on hand) will take a few hours which can delay or cancel a trip. I flew to Galveston that weekend for the competition, but it was eating at me. 

-David

[DCarlton]

6 hours ago, 00-Negative said:

The final product uses 1/8" silicone baffle seal as suggested. I've replaced the seal 2x. After that flight, my A&P and I replaced the worn seal with the same material that was already in place which is a thinner, more flexible rubber material. I did find the original broken piece of seal behind the air filter. The first seal we made lasted less than 100 hours and I found it cracking again on the top. I then used the 1/8" silicone baffle material  which was trimmed to fit perfectly in the opening without bending or stressing the seal material but still touching the side walls of the RAM opening with the door fully closed. The previous thinner seal material was cut slightly oversized and flexed against the side walls with the door closed which caused it to crack in short time. The 1/8" baffle material will not allow flexion in such a short gap, so it will need to be trimmed absolutely perfectly. As mentioned in the thread above, I had elevated silicone levels in my oil analyses through the first few months of owning my plane which I attributed it to new silicone rocker cover seals, push rod seals, air filter had not been changed in 2-3 years,  replacing worn intake accordian boot, and other such overlooked maintenance items through the first several months of ownership. After the second RAM air door seal, my silicone levels came down. 

The ram air door can be removed easily without removing lower cowl or disconnecting anything. Remove the air filter and open the RAM air door nearly all the way. You can then access either 2 or 3 round head machine screws on the back of the ram air door and slide the door off of the tongue that holds it in place. There are flush rivets holding the seal in place. My A&P told me to drill out the rivets, cut a new seal, come back and we'll put it back together and re-install. I went to my shop and completely shredded the thing with terrible technique and ignorance about rivets. So we then fabricated a new door with a new seal. 

The RAM air door can easily be reproduced with hand tools. It might be a good idea while you're doing this to fabricate a completed and painted 2nd door with a new seal in place. I have compiled a hangar full of backups like this. I can remove and replace that RAM air door in a few minutes. But to remove, drill out the rivets, cut a seal, and re-install (If I have the materials on hand) will take a few hours which can delay or cancel a trip. I flew to Galveston that weekend for the competition, but it was eating at me. 

-David

Got any pics of the RAM door removed with the old/new seals?  I've wondered about this too and what happens to seal parts if they get sucked in.  I'm not I even sure want a seal that might age and get sucked in.  I need to take another look at the system to better understand it.