<VV> More on valve seat failures

[jvhroberts at aol.com]

 Actually, the worst temp swings in air cooled aircraft engines from full power at altitude to a dive to lower altitudes. That's where the shock cooling takes place. 

That being said...

Some seats are screwed in and pinned against rotation. Some are really deep and large. Some are made of alloys that more closely match the CTE of aluminum. Or any combination thereof. 

Most aircraft engines have to be able to be FAA certified. Meaning, any problems like this must be designed out of the engine before it gets that approval. Also, most aircraft engines are relatively slow turning, even the geared ones. And all aircraft engines are relatively low specific output compared to a Corvair engine. And ALL of the commercially available engines have adequate cooling under all conditions. Properly tuned and operated aircraft engines will never see the sort of CHTs that a Corvair engine hits. 

 

John Roberts
 

 

-----Original Message-----
From: Kerwin Nailor <kerwinnailor at verizon.net>
To: virtualvairs <virtualvairs at corvair.org>
Sent: Wed, May 9, 2012 8:50 am
Subject: <VV> More on valve seat failures


How do the air cooled aviation engines, flat and radial, deal with keeping 
seats in place? They get some pretty dramatic changes in temp, like heavy 
rain.


Kerwin Nailor
kerwinnailor at verizon.net 

 _______________________________________________
This message was sent by the VirtualVairs mailing list, all copyrights are the 
property
of the writer, please attribute properly. For help, mailto:vv-help at corvair.org
This list sponsored by the Corvair Society of America, http://www.corvair.org/
Post messages to: VirtualVairs at corvair.org
Change your options: http://www.vv.corvair.org/mailman/options/virtualvairs 
 _______________________________________________