Are Hardened Valve Seats Necessary?


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By oldcarmark - 15 Years Ago
Looks like I will be doing a valve job on my 56.I am pretty sure the heads are original.Do I need to have hardened valve seats installed when redoing the heads?
By crenwelge - 15 Years Ago
It depends on how much you care to spend. Hard seats are better. I have never had any because I still have my own valve grinding equipment and I would have to outsource the seats. I do use lead substitute though. I don't know if its necessary for as little as I drive my jalopies. Unleaded really played havoc on farm machinery that was built in the leaded gas days as well as older farm pickups that pulled stock trailers. I was the last distributor to sell leaded gas in my area and then I sold unleaded with lead additive until it became illegal in 1998. I do however sell lead additive in bottles which is legal.
By mctim64 - 15 Years Ago
It's best to put hard seats in as long as you have it apart but if the seat isn't beat in to far you can cut the cast iron and it will last a few thousand miles on unleaded.
By Ted - 15 Years Ago
I’ll add that without the hardened seats, valve guide wear increases significantly which ends up just costing more in the long run.  If it’s a vehicle that’s just being driven 2500 miles a year or less, then the cost of hardened seats my not be justified depending upon your budget.  70K miles on unleaded fuel without hardened seats seems to be the record here with 35-40K miles being the average where the heads must be pulled again and worked on.  At that point, most customers simply opt to go with the hardened seats and never look at the inside of their engines again.
By oldcarmark - 15 Years Ago
Thanks Ted. I just talked to an engine machinist about the seats.He says only exhaust need replacement seats as long as the intakes can be reground.I think they all should be done.Opinion?
By HT32BSX115 - 15 Years Ago
oldcarmark (9/17/2009)
Looks like I will be doing a valve job on my 56.I am pretty sure the heads are original.Do I need to have hardened valve seats installed when redoing the heads?




You should put hardened seats in your engine if you have the heads off. Now, having said that, I ran my 57 Ford 292 for many years on unleaded gas and never had a problem. I'm sure it was just pounding the seats to death.



When I had the 292 that's going on my F600 rebuilt, I asked about hard seats. The shop owner told me that "everybody" puts hard seats in old engines when they rebuild them without even asking.........It's a non-issue nowadays.....They just do it.



Incidentally, you can run your engine on an AVGAS mix if you're worried about valve seat damage. Just don't tell anyone that you're doing it. It's a violation of federal law if you run it on the highway with leaded fuel.



Cheers,





Rick






By Hoosier Hurricane - 15 Years Ago
Mark:

I for one agree with your machinist, if you put in seats, only the exhausts need it, unless the intakes are pounded so badly that they can't be ground.  But if your '56 heads are pounded that badly, you can cut the intake seats oversize and put 1.94 valves in them.

By oldcarmark - 15 Years Ago
Thanks for that suggestion John.What is the favoured head gasket to use?NOS Ford good or no good?
By speedpro56 - 15 Years Ago
I'd use composit over steel anytime. Felpro or Best gaskets should do fine. That's probably what most of us use.
By oldcarmark - 15 Years Ago
Now another question about seats.I understand they come in tungsten steel or chrome of some kind.Tungsten is about $1.00 more each.Is that the way to go?
By Hoosier Hurricane - 15 Years Ago
Chrome steel is probably the seat of choice.  Tungsten is probably used in extreme duty engines, industrial and over the road trucks.  What does your machinist say?  8 bucks more for a valve job isn't much if they are that much better.
By oldcarmark - 15 Years Ago
Thanks John.Actually the hi-chrome are cheaper to buy than the Tungsten.I am trying to get a little better informed on my options on redoing these heads.As much as my machinist knows HOW to recondition these heads its up to me on what parts and how much I want to spend.I value the input from members like yourself who have the experience with these motors.