Valves

[70MC]

I am using Ferria 6000 series valves that have had 1 valve job done and also had a clean cut taken off the stem tips. I now have the heads off and realize that i had valve float, the valve tips have a circular pattern on them and look as though they have a very very small cup, or dent in them. The valve stem tips have a steel tip that looks to be about .100 thick. I want to have a cut taken off the tips again but fear they are hardened only a few thousands deep. How much can be taken off a valve tip with out worring?

[maxracesoftware]

The valve stem tips have a steel tip that looks to be about .100 thick. I want to have a cut taken off the tips again but fear they are hardened only a few thousands deep. How much can be taken off a valve tip with out worring?

i always thought the Hardened-Tip was Heat-Treated or hardened throughout ??

i've reground a ton of valve tips so far
and haven't noticed any increased wear out of ordinary
due to grinding too much off passing thru hardness layer ?

i get to see the reground Tips often enough on refreshens
and .005 to .015 should be plenty safe

sometimes i've had to grind +.020" off , and haven't noticed any accelerated Tip wear or anything unusal ?

[OldSStroker]

Yes, a thin case on an inserted tip would be a dumb design. The tips should be thru-hardened and should be the same no matter how far you grind into them.

[user-z68766209]

Up to .030 is OK.
Brian B

[70MC]

Last month i called Ferria and asked the same question to them, the tech told me no more than .003 should be ground off. But that did not sound right to me since valves could be given many valve jobs, it would seem to make since that the tips could be touched up a few times.
That was far from the first time i have gotten bad info from a tech.
Thanks for the help everyone.