Valve Grinding
 

Hi All,
I have been grinding some Model A valves with my valve grinder and am finding by the time I am able to get a clean face there is not a lot of margin left. These are stainless valves with 70k+ miles on the motor but valves have not been ground before. Never had this concern before with flatheads and SBC's, newer motors etc.
Anyone else experienced this?


Thanks, Steve

Re: Valve Grinding
 

Don't know what your expecting, but with 70,000 miles, I would not grind them I would trash them. Valves are not that expensive. If you run a thin lipped valve, it is more likely to burn in the future. Also stem wear is likely. I wouldn't bother with them. JMO

Re: Valve Grinding
 

I don't know the specs on a model a, but I've found that a 1/32" margin on most old cars is enough.

Re: Valve Grinding
 

Specs for a margin can be tough to define. Valves come in all sizes. But a good rule of thumb, if it ends up being 50% of that on a new valve then I trash it.

Re: Valve Grinding
 

Are they original Ford stainless valves?---- they have a pretty thin margin to begin with

Re: Valve Grinding
 

These are aftermarket, had to go a ways to get a clean face. Guess I should just change them out. Like upgrading a computer, you end up replacing everything in the end.
I have done a lot of motors over the past 50+ years, never had to go that far into the face to clean it up.

Re: Valve Grinding
 

Depending on where your seat is you can also turn them to 90 degrees in you valve Facer and gain some margin. Just saying.

Re: Valve Grinding
 

Thats a good point. If the seat contact can be moved toward the stem you could maybe grind some more margin. I happen to like the contact area near the stem.