Scott's Sonex 1629 - N629SX

[ScottM-Sonex1629]

Some additional engine progress! Case is assembled with crank and cam shafts, and sealed up. First two sets of pistons/cylinders are measured, shimmed & RTV sealed to case. Cylinder head is sitting in position for glory sake! Still need to clean up the metal shavings and gasket up the push rod tubes and do a final install. Just doing one side of the engine at a time (unlike assembly direction instructions). I'm working with gravity and not trying to fight it!

[Bryan Cotton]

Looks good Scott. Prop may need some balance though.

[SonexN76ET]

I don't think you want to seal the case with RTV! Sonex is adamant that you use the designated aviation sealer in your assembly manual. I originally did my case with RTV and after hearing the disastrous results that can occur and after talking to Kerry took mine apart and used the proper sealant.

[Sonerai13]

There are very few places on the AeroVee engine where RTV is appropriate. These are called out in the manual. Sealing case halves and cylinder bases are NOT the places where RTV should be used. PLEASE follow the manual when assembling the engine, including use of appropriate sealers in appropriate places, and you will avoid a lot of trouble.

[MichaelFarley56]

Scott can fill you in for sure, but I don't believe he used red RTV for the case halves. I think it's Permatex (Loctite) Anaerobic Gasket Flange sealant, supposedly the same stuff Rotax uses on their engines. A lot of people on the old Yahoo boards swore by this stuff and after using it myself I can say its a good product. I tried to use the Aviation Gasket sealant (#3 I believe) and that was about the most worthless product I've ever tried! It never did set up after 10 days untouched; I ended up disassembling parts, cleaning, and rebuilding after trying that stuff.

I think the only thing Scott has RTV'd is the cylinder shims.

[ScottM-Sonex1629]

Mike is correct. Anaerobic Flange gasket maker on the case halves. High temp red RTV only on the cylinder shims.

[SNX1508]

There are very few places on the AeroVee engine where RTV is appropriate. These are called out in the manual. Sealing case halves and cylinder bases are NOT the places where RTV should be used. PLEASE follow the manual when assembling the engine, including use of appropriate sealers in appropriate places, and you will avoid a lot of trouble.

Hi Joe,

I will begin assembling my AeroVee in the near future, so these posts on that subject caught my attention.
The AeroVee assemble manual, REV U, calls for Permatex Aviation Form-A-Gasket #3 or Flange Sealant, but other posts here say the #3 is not up to the task. Shall I follow the assembly manual and hope for the best?

Terry

[MichaelFarley56]

There are very few places on the AeroVee engine where RTV is appropriate. These are called out in the manual. Sealing case halves and cylinder bases are NOT the places where RTV should be used. PLEASE follow the manual when assembling the engine, including use of appropriate sealers in appropriate places, and you will avoid a lot of trouble.

Hi Joe,

I will begin assembling my AeroVee in the near future, so these posts on that subject caught my attention.
The AeroVee assemble manual, REV U, calls for Permatex Aviation Form-A-Gasket #3 or Flange Sealant, but other posts here say the #3 is not up to the task. Shall I follow the assembly manual and hope for the best?

Terry

Hi Terry,

Always follow the manual!

Mike

[JerryCPP]

I assembled my AeroVee using Dirko silicone type "THE" sealant for VW and Porsch, according to my local foreign parts store. It is made in Germany, so it had to be perfect. It leaked. I took it apart and tried again, being even more careful. It leaked again. I called Kerry and asked what that blue stuff is in the assembly video. He said to use #3 Permatex. The third time, it almost doesn't leak. If anyone has a sealer that actually works, I'd like to know what it is, not just a general reference to "Flange Sealer."

[ScottM-Sonex1629]

This is the product Mike used and gave me a tube of which I used on my case:

http://www.permatex.com/products-2/prod ... ker-detail