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Hardened valve seats

 
boomer300
User
Posts: 97
Joined: 05/08
Posted: 07/26/14 02:14 PM

When did Ford start using hardened seats? I am specifically looking for 351W heads C9OE and D0OE. I don't want to burn a head. thanks  

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cushman350
Enthusiast
Posts: 648
Joined: 07/06
Posted: 07/27/14 08:45 AM

http://www.fordmuscleforums.com/all-ford-techboard/424842-unleaded-gas-valve-seats.html

Unleaded gas came out in 1975, as did hardened seats.

Many 'hardened' seats that head shops install aren't really any different than the metal they carve out of the heads for the install. Special seats, like Steelite, are significantly more expensive, and are a PITA to cut a seat on. These are the only real 'hardened' seats out there.

Most vehicles do NOT need hardened seats. Seat erosion is most common on engines that are run under a hard load for extended periods of time, such as those used in tow vehicles. Hotrods are are generally just run hard for short periods, and don't have a problem.

Carving big chunks of cast iron out of the valve seat area for their installation weakens the head and can lead to cracks. If the head is cut too deep, the shop can break into a water jacket, and the head will be junk. Plus, if the seat is not installed properly, it can fall out and cause all sorts of problems. In my opinion, seats should not be installed in most engines unless they are needed for repair.

An alternative repair for sunken seats is the installation of slightly larger valves. (1.84"/1.56" 351W size for example in a 289/302) This puts the 'new' valve seat out past the sunken area, and raises the valve back up nice and high where it should be.

Good Luck!  

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boomer300
User
Posts: 97
Joined: 05/08
Posted: 07/27/14 08:52 AM

Wow. Great information.  thanks.  

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