Stainless Steel Valves and Hardened Valve Seats

[Chatt69chgr]

Everyone knows that 906 heads do not have hardened valve seats.  They also know that 452's do.   Someone told me that you don't have to worry about valve seat erosion in 906's if you just use stainless steel valves.  In other words, the use of stainless steel valves means you don't have to worry about whether your heads have hardened seats or not.  This sounds crazy to me and I don't believe it.  Could someone comment on this.  Thanks.

[Purple440]

I thought lead in the old fuel kept the non-hardened sets from getting fubar. 

[Chatt69chgr]

Thats what I thought too.  The person that was using the 906's with stainless steel valves that made this claim mostly just takes his car to the strip.  I do think I have heard that erosion of the valve seats occurs over a fairly long period of time.  So if you were not accumulating a lot of miles on the car, maybe it would end up not being a problem.  I have a nice set of 452's myself----I just want to know the answer to this for academic reasons.   

[firefighter3931]

Opinons are mixed on the SS valves with unhardened seats. I prefer a later head with the hardened seats and a SS valve....that is the best of both worlds. 

The theory behind ss valves and non hardened seats is that there is less metal transfer between the valve and seat which in turn reduces wear. It really depends on how much you will drive the car and how long you want the heads to last. If you're only driving a few thousand miles a year you could get several years out of a set of heads that don't have the induction hardened seats.

Of couse it's just as easy to use a set of 452 castings and be done with it. 



Ron

[Chatt69chgr]

Thanks Ron.  I appreciate the explanation.  I do plan on using the 452's I have and stainless steel valves.