what caused valve seat to drop?

K

Kyle_truck_pull

New member
Joined
Aug 13, 2010
Messages
42
friend of mine dropped a valve seat on #6 cylinder (exhaust), the piston is pretty bad and the head not so good. what causes the seats to fall out like this? the head was ported, and only has 2,000 miles on it since it was replaced. the old head had several cracks and burnt seats/valves. just wondering what could of caused this. I havent seen one frop before, just heard about it before.
any info would be great!
 
got hot and the valve seat came out? that would be my guess. depends on who put the seats in and if they oversized them and pressed them in.
 
If they are anything like panties this
[ame="http://www.youtube.com/watch?v=ASu3hMxjKQ8"]http://www.youtube.com/watch?v=ASu3hMxjKQ8[/ame]
 
Not nearly enough information to even begin to trouble shoot the problem. As a general answer though... Heat causes the metal around the seat to expand more then the seat itself. When the seat cools it contracts more then the head and the valve seat drops.

The possible causes are just to many to list. One think that is pretty clear by your description is that the seats were not, rolled, pinned, or other method used to retain the seats. These methods if done properly won't keep the seats from getting loose, but they will keep them from dropping. That will at least limit the destruction.

Paul
 
is it possible that the shop that put the head together used seats for the wrong year head? I dont know what the differences are between years on the 24 valve heads, but I heard that certain years they did have problems with the valve seats. I know they ported the head for him, but before they did they wanted the old head to practice on. that alone would of scared me away from that shop. Also this new head is supposed to be the head off of the better year. if that makes sense
 
I dont believe there is a difference between years. Like paul said they probably didnt use a method of retaining them in the head. If they did use one of those methods they didnt do it properly
 
You must log in or register to reply here.
Back
Top