Pulled the head of the 25 I bought to see what the water passages look like, they are clear in both the head and block. But while I was that far into the engine I broke the manifolds loose and peeked
into the passage with a mirror. I see a big step between the valve stem and head. Looks like I will be changing the valves. I think I have determined by reading old threads on sizing the valves that the standard stems should be 0.312, am I right?
But I can not figure out what diameter the standard heads should be. Can some one aim me at a set of specks that show this.
Langs catalog use to have that on the inside of the front cover. Very useful info provided by one of our vendors in the hobby. if you have one you can find most of the specs right there,
You can also download a complete catalog.
Hmmm,...."Valve tappet to stem clearance"........022" - .032". Seems a bit excessive maybe?
That is for the original Ford valve, two-piece, with the steel shank and iron head.
The heat expansion of new one piece steel valves is much less, so the settings are different for modern parts.
Ford two piece valve
Those are the kind of gaps you would see using the piston travel method of setting the valves.